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Tidal Power: Making Waves in the Energy Game

Allen Huang — Thu, 12 Dec 2024 15:29:01 +0000

EARTHDAY Explainers - VII

Tidal Power: Making Waves in the Energy Game

By Allen Huang

As the world races to combat climate change and reduce our dependence on greenhouse gas emitting fossil fuels, a centuries-old energy source is making waves—literally. The rhythmic rise and fall of ocean tides, driven by the gravitational forces of the Moon and Sun along with the Earth’s rotation, is emerging as an increasingly reliable source of renewable energy.

Tidal energy shares similarities with hydroelectric power, particularly in its use of natural water movement to generate electricity. However, it generally requires a smaller geographic footprint as it does not require large dams or barriers or reservoirs, and, depending on the technology used, can have a lower impact on local ecosystems.

These advantages make tidal energy a compelling solution for coastal communities, offering a reliable and consistent source of renewable power that can help reduce carbon emissions. Unlike wind and solar, which are intermittent, tidal energy is predictable, driven by the natural gravitational forces of the moon and sun, ensuring a steady energy supply. Moreover, tidal power systems can be designed to have minimal impact on marine ecosystems, with some technologies allowing for integration into existing coastal infrastructure.

By tapping into the vast energy potential of the oceans, tidal energy can power local grids, support energy independence, and help reduce reliance on fossil fuels, all while preserving the health of marine environments. While the modern world is waking up to the power of today's energy - other ancient civilizations were all too aware of its power.

A Little Bit of Wave History

The origins of tidal energy date back over two thousand years, with the use of tide mills occurring in the Roman Empire around the 1st century BCE.

These early systems harnessed the natural ebb and flow of tidal waters to power grain mills. A typical tide mill featured a waterwheel or a set of paddles positioned in a tidal channel or basin. As the tide came in, water would fill a turn the wheel. The movement of the wheel was then transferred via a system of gears to rotate the millstones, grinding grain into flour. During the falling tide, water was released through sluices, and the process would reset as the tide came back in.

In many tide mills, the waterwheel operated both as a power source for grinding and a mechanism for controlling the flow of water, making them highly efficient in areas with strong tidal currents. By the 7th and 8th centuries CE, tide mills were common across Europe, especially in tidal regions like Britain, France, and the Low Countries. These systems were not only used for milling grain but also for other tasks, such as pumping water and sawing timber.

Some continued to operate well into the 19th century, long after steam power had begun to replace traditional water mills. But it is the ingenuity of these early tide mills which laid the groundwork for the advanced tidal power systems we are seeing gradually develop across coastal locations today.

What’s the Big Win With Tidal?

The biggest benefit of tidal power comes from the high level of power conversion rates. Similar to hydroelectricity, approximately 80% of the power the turbines collect from tidal energy becomes usable electricity.

However, tidal energy systems can only generate electricity during tidal flow periods, typically 4-6 hours per tidal cycle. This creates intermittency, as tidal energy production pauses between cycles. While tidal is predictable, it offers less consistent energy generation compared to wind and solar, which can operate for more extended periods.

Predictability and Reliability

Plus tidal energy is one of the most predictable forms of renewable energy because tides follow a regular, cyclical pattern driven by the gravitational pull of the moon and the sun. This means that tidal energy generation can be forecast years in advance, making it more reliable than other renewable sources like wind and solar, which are dependent on weather conditions.

Tidal energy is not weather-dependent. Tidal energy production happens every day, without interruption, as long as there is a tidal cycle. This provides a consistent and stable supply of energy for coastal communities, and even potentially for the wider national grid.

Because tidal energy is predictable and reliable, it can act as a complement to other intermittent renewable sources like wind and solar power. For example, when solar or wind energy output is low due to weather conditions, tidal energy could fill the gap, providing more stable and continuous energy. Hybrid systems that combine tidal energy with wind and solar could be highly effective in achieving grid stability and reducing the reliance on fossil fuels.

How Does Modern Tidal Power Work?

Primarily speaking, tidal energy systems primarily fall into two categories: tidal range power, by which tidal barrages are the most common form, and tidal stream power. While tidal ranges generate electricity in a fashion similar to traditional hydroelectric power, with water falling from an elevated place onto turbines to generate electricity, tidal stream power actually works more like wind energy, with bladed turbines rotating from the force of the ocean currents to power generators. All of these systems are each suited to distinct conditions and operational requirements.

Tidal Range Energy In More Detail

Tidal range refers to the vertical difference in height between high tide and low tide. It's a measure of how much sea level rises and falls due to the gravitational pull of the moon and sun, along with the Earth's rotation. The bigger the range, the more potential energy can be generated. In places where the tide has a large range—sometimes as much as 15 meters or more—there is more energy available to capture.

Tidal range systems work best in areas with strong tidal movements and wide, shallow coastal regions. These include places like the Bay of Fundy in Canada, where the tidal range can reach up to 16 meters, or the Severn Estuary in the UK, where the difference can be more than 13 meters. Other countries with favorable conditions include South Korea, France, and parts of China, which have natural harbors, estuaries, or coastal regions that experience high tidal fluctuations.

In case you want more detail, there's a formula for calculating the amount of energy that can be produced from tidal range systems: 𝑃 = 𝜌 ⋅ 𝑔 ⋅ 𝐴 ⋅ ℎ²

Where:

𝜌 is water density

𝑔 is gravitational acceleration

𝐴 is the impounded area (the area where water is collected)

ℎ is the height difference between high and low tide.

The larger the tidal range and the area where water can be captured, the more energy can be generated

Tidal Stream Energy In More Detail

Tidal stream, on the other hand, refers to the horizontal movement of water caused by tidal currents, which occur when the tide goes in and out. These currents are created as the ocean water moves back and forth, pulled by the gravitational forces of the moon and sun. The result is fast-moving streams of water, much like underwater rivers, that can flow through narrow channels, along coastlines, or between islands.

Some of the best locations for harnessing tidal stream energy include the Pentland Firth in Scotland, where tidal currents reach speeds of up to 10 knots, or the Mersey Estuary in England. The Strait of Messina between Italy and Sicily also has strong tidal flows, as does the Cook Strait in New Zealand. These areas have strong, consistent tidal currents that can generate enough energy to power local communities and industries.

The energy from these fast-moving tidal streams can be captured using special machines called tidal stream generators, which work much like underwater wind turbines. As the water flows past these turbines, it causes the blades to turn, and that turning motion is converted into electricity. This clean, renewable energy can be used to power homes, businesses, and even entire cities along coastlines.

In contrast to tidal range systems, which rely on the rise and fall of water levels, tidal stream energy uses the movement of the water itself, making it a more flexible option for areas with strong, consistent currents. And since tidal stream generators can be installed on the seafloor, they have less impact on the surrounding environment compared to large tidal dams.

Tidal Barrages In More Detail

Tidal barrages, which are estuarine barrages, akin to massive dams. Built across estuaries (a partially enclosed body of water that connects rivers or streams to the open sea) with high tidal ranges, they trap water during high tide and release it through turbines at low tide, generating electricity.

The power generated is proportional to both the area of the impounded water and the square of the height difference between the water levels inside and outside the basin, making tidal range energy most effective in locations with large natural tidal ranges and suitable geography for creating large impoundments.

Unlike river-based hydroelectric facilities, where water can flow only by one direction, tidal barrages can be either one-directional or two-directional, also known as “double generation.” The traditional unidirectional generation produces electricity during one phase of the tidal cycle, which is typically when water flows out of the reservoir through turbines during low tide.

However, two-directional generation harnesses power during both tidal phases: as water flows into the reservoir during high tide and as it flows out during low tide. Whether or not a tidal barrage is one or two-directional usually depends on the tidal range itself: the larger the range, the more likely it would be a one-directional facility.

To sum up how the tidal energy methods differ:

Tidal range is the difference in water levels between high and low tide, which can be used to generate energy.

Tidal stream, uses moving water to spin turbines and generate power.

Tidal barrage is a specific system that captures tidal range energy by building a dam to trap water and release it through turbines.

What Other Emerging Tidal Technologies Exist?

In addition to the relatively mature tidal barrages and tidal streams, there are other new techniques being developed to harness wave power: tidal lagoons and dynamic tidal power. Both of which are still mostly theoretical concepts that have not really come to fruition.

Tidal lagoons, which is also a form of tidal range power, do not require the existence of estuaries to be built. As the name suggests (lagoons are semi-enclosed bodies of water slightly separated from the ocean), tidal lagoons are built as standalone structures that can be placed in areas with high tidal ranges to form artificial lakes.

These lagoons use walls to trap water during high tide and release it through turbines during low tide, generating electricity. Tidal lagoons can also function in a two-directional manner, generating power as water flows both into and out of the lagoon, without being disruptive to the local environment as much as the tidal barrage.

Dynamic tidal power, or DTP, on the other hand, is a much bolder attempt to collect electricity from tidal power. It involves constructing long, dam-like structures—potentially up to 60 kilometers—in open coastal waters at an angle to the shoreline. These structures, equipped with turbines, exploit the phase difference between tidal currents on either side of the dam to generate electricity. As tidal currents interact with the dam, a pressure differential is created, driving water through the turbines and producing power.

Neither Tidal Lagoons or Dynamic Tidal Power Are Widespread - Why?

Neither tidal lagoons nor dynamic tidal power have been realized on a large scale due to the significant technological, financial, and environmental challenges both of them come with. Firstly tidal lagoons require substantial upfront investment and face uncertainties around their long-term economic viability. For instance, the proposed Swansea Bay Tidal Lagoon in the UK has been indefinitely stalled due to the high costs as well as concerns about its cost-effectiveness compared to other renewable technologies.

Dynamic tidal power faces even greater hurdles, and the concept so far has not progressed beyond theoretical models. The immense scale of construction and lack of proven prototypes make it a high-risk venture, at a time when other more feasible alternatives already exist.

Challenges of Tidal Power: Cost

The biggest hurdle for wider tidal power adoption is indeed cost. Initial capital investment for building tidal power facilities can be very high compared to other renewable energy sources like wind or solar. This is because tidal power requires expensive infrastructure, including dams, turbines, and complex engineering solutions that need to withstand the harsh conditions of the ocean.

For example, the Sihwa Lake Tidal Power Station in South Korea, with an installed capacity of 254 megawatts, is one of the largest tidal power stations in the world. It was built at a cost of $298 million in 2011. Plus, the cost per megawatt of capacity for tidal power is higher compared to other renewable energy sources like wind or solar.

Environmental Concerns

While any damage tidal may do pales in comparison to the harms of fossil fuels there are some environmental impacts associated with tidal barrages in particular. Researchers suggest that tidal barrages could destroy benthic habitats (the physical environment on the bottom of a body of water where organisms live and grow), causing potential disruption to underwater ecosystem patterns. But unlike land-based solar farms or wind turbines, tidal energy installations often have a smaller geographic footprint overall.

Then other concern is sedimentation and tidal patterns can be altered by the tidal barrages which also threaten migratory fish routes, and given tidal barrages strongly resemble the structures used to make impoundment dams, the challenges they pose for the environment do bear an eerie resemblance.

For tidal stream facilities, despite the relatively low impact to the environment, the harsh marine conditions themselves pose their own set of challenges toward the long-term operability of these projects. Tidal energy systems are constantly exposed to powerful ocean currents, wave action, and saltwater corrosion, all of which can degrade materials and components over time.

Having said all of this, like other forms of renewable energy, tidal power produces zero emissions while generating electricity. Unlike fossil fuels, tidal energy doesn’t release carbon dioxide (CO2) or other harmful pollutants into the atmosphere, making it an important tool in the fight against climate change.

Will Tidal Energy Have A Future?

The global potential of tidal power in theory is enormous. One estimate in 2023 suggests that tidal power globally could produce 1,200 terawatt-hours of electricity per year, which is 14% of the global renewable energy production level in that year. However, that number is under threat, ironically, from rising sea levels, as shifting geographies could render formerly ideal locations useless.

Tidal energy offers many unique advantages: it's predictable, reliable, and on the whole it is environmentally friendly. It’s a great match for coastal communities and has the potential to complement other renewable energy sources like solar and wind. While challenges like high initial costs and some environmental concerns do exist, tidal power is a promising renewable energy solution, especially as technology advances and costs decrease.

Tidal power offers a predictable, sustainable wave of opportunity—meaning our oceans might be the key to a cleaner, more reliable energy future.

The post Tidal Power: Making Waves in the Energy Game appeared first on Earth Day.

Turning the Tide: The Story of Hydropower’s Role in the Renewable Energy

Allen Huang — Wed, 06 Nov 2024 14:15:11 +0000

EARTHDAY Explainers - VI

Turning the Tide: The Story of Hydropower's Role in the Renewable Energy

By Allen Huang

Hydropower harnesses the dynamic movement of water to generate electricity and is one of the oldest and most widely used renewable energy sources in the world. It is one of the world's oldest renewable energy sources, dating back 2,000 years to a time when both the ancient Greeks and Romans used water wheels to grind grain and other tasks.

Today, hydropower is the largest renewable electricity source, generating around 16% of the world's total electricity. China, Brazil, the United States, Canada, Russia, India, Norway, Venezuela, Sweden, and Japan have all been successful in using hydroelectric power to feed their electricity grid but hydro power comes with numerous points of view, debates and controversies. Let's take a closer look at hydropower's development journey and its outlook for the future.

How Does Hydroelectric Power Work?

Hydroelectric power is generated by harnessing the potential energy of water as it flows from higher elevations to lower ones, reminiscent of the dramatic rush of waterfalls. This movement is captured using turbines that are set in motion by the flowing water. As the turbines spin, they drive generators that convert this mechanical energy into electricity.

When electricity is needed, water is released from the reservoir and flows through a penstock (a large group of pipes) to a turbine at a lower elevation. The moving water spins the blades of the turbine, which is connected to a generator. The generator converts the mechanical energy of the spinning turbine into electrical energy, using an electromagnetic process.

The electricity is then sent through transformers to increase its voltage for efficient transmission over power lines to homes and businesses. Such a process relies heavily on the hydrological cycle, where the sunlight evaporates water downstream, leading to precipitation that flows through rivers, providing a consistent and renewable source of energy.

You can calculate the efficiency of hydroelectric power generation depending on factors such as the flow of water (Q), measured in cubic meters per second; the height or head (H) through which the water falls, measured in meters; and the overall efficiency (η, also known as Eta) of the system, which is usually around 90 percent.

When you multiply these factors together with the gravitational constant (the acceleration that objects experience when falling freely near the Earth's surface, which is 9.81 meters per second squared), you get a power output measured in kilowatt hours (kWh).

Let’s take an example of a hypothetical dam built on the Hudson River based on this formula. The average flow rate (Q) of the Hudson river is around 600 cubic meters per second. Assuming a dam being built at a 50 meter head (H) and the 90% efficiency (η), this dam will lead to approximately 265,000 kWh, which means this one dam produces enough electricity to power 25 American households for a year in just an hour.

Hydroelectric plants can range in size from small micro-hydro systems generating a few kilowatts to massive installations like China’s Three Gorges Dam, which has a maximum installed capacity of 22.5 gigawatts, equivalent to what 25 households use in a year within an hour.

Regardless of scale, the underlying principle remains the same: converting the gravitational energy of falling water into usable electricity. However, the site-specific nature of hydroelectric power means that each project is designed to fit the local geography, hydrology, and energy needs.

Hoover Dam, on the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona

Attribution (CC BY 2.0)

History of Hydroelectric Power

Water has flowed across the Earth for millennia, shaping landscapes and powering human innovation. The energy generated by this movement has long been harnessed to drive various industries, even before the Industrial Revolution, in the form of watermills and aqueducts. While the use of water wheels to grind grain and power machinery dates back thousands of years, the birth of modern hydroelectricity occurred in the late 19th century, during the Second Industrial Revolution.

In 1882, the world's first hydroelectric power plant began operation on the Fox River in Appleton, Wisconsin, lighting two paper mills and a residence. Early installations, similar to that in Appleton, emerged in regions with access to significant water resources, such as the Alps and the Great Lakes basin in North America.

A key reason for the advancement in hydroelectric power was the evolution of turbines. The transition from water wheels to turbines allowed for greater energy output from higher falls. The development of impulse turbines like the Pelton wheel further enabled hydroelectric projects in high-head environments that waterwheels couldn’t do.

Just a few decades later, hydropower plants were being built at a rapid pace around the world, ushering in a new era of renewable energy. By the 1940s, hydropower accounted for around 40% of electricity generation in the United States.

The pièce de résistance of all this industrial hydroelectric boom was the Hoover Dam on the Colorado River, situated between Nevada and Arizona. Built during the Great Depression as a means to control the waterflow, manage irrigation and produce electricity, its construction took six years and nearly a billion dollars in today’s money. Meanwhile, the Grand Coulee Dam on the Columbia River in Washington State, which was built around the same time, has an installed capacity of 6809 mWh, is the largest dam in North America, and among the largest hydroelectric projects in the world. However, due to the social and environmental costs of building these projects, large impoundment constructions have stopped in the United States for decades.

The post-World War II period saw a significant expansion of hydroelectric power projects, particularly in developing countries. Governments and international organizations recognized the potential of hydroelectric power to provide clean, renewable energy and stimulate economic growth, but it would gradually give way to fossil fuel and nuclear generation despite its continued usage and development to satisfy the need for energy use in sectors such as infrastructure, military and transportation.

Not All Hydroelectric Power Plants Are The Same

There are several types of hydroelectric plants, each suited to different environments. The most common type is the impoundment facility, which is the most common type of hydroelectric dams in the world and the one that many would most easily recognize in photos.

They feature a large dam wall that contains and stores river water in a reservoir. When electricity is needed, water is released from the reservoir, and flows through turbines, to generate power. The reservoir provides a stable, controllable flow of water, allowing the plant to ramp electricity output up or down relatively quickly to meet changing electricity demand, with the Hoover Dam being perhaps the most famous example.

Other notable examples of this infrastructure include Canada’s Site C Dam and Churchill Falls Generating Station, both integral to the country’s power grid. In Brazil, the Belo Monte dam and Itaipu dam (which crosses between Brazil and Paraguay), serve as cornerstone facilities, supplying a substantial portion of the country’s electricity. Norway’s Sima Power Plant is another example, utilizing impoundment hydropower to support national energy needs.

What makes hydropower one of the most controversial in renewable energy is the well documented environmental and ecological issues created as a result of these constructions, particularly impoundment facilities.

Dams can harm aquatic ecosystems in several ways. They disrupt the flow of sediments, which are important for wildlife and farming. When plants and trees are submerged underwater due to dam construction or flooding, they can decay and release harmful greenhouse gasses like methane and carbon dioxide, contributing to climate change. This loss of vegetation also disrupts local ecosystems and wildlife habitats.

As rivers naturally flow, water transports sediments downstream to replenish soils and maintain the ecosystem's circulation and overall health. When dams are constructed, the sediment will start to build up in reservoirs, resulting in a lack of supply and the eventual erosion of the habitats downstream and build up behind the walls of the reservoir causing damage to the dam or require frequent removal of sediment. The degradation of habitats will impact both the wildlife and local agriculture.

Dams block the migration route of fish, especially species like salmon, that rely on free flowing rivers to spawn. While there have been efforts to mitigate the effects through fish ladders and bypass systems, the success is at best varied (actually mostly unsuccessful). At times, the failure of the bypass measures have resulted in the costly removal of dams at times in emergency efforts to revive fish populations:

Elwha River, Washington: The Elwha and Glines Canyon Dams were removed in 2011 and 2012, respectively. This restoration project aimed to revive the salmon populations that had significantly declined due to the dams blocking their migration routes.

Breach of the Klamath River Dams, California/Oregon: In 2021, four dams on the Klamath River were removed to restore salmon and steelhead populations. The dams had disrupted fish migration and contributed to ecological issues in the river.

Maine’s Penobscot River: A series of dam removals began in 2004 with the removal of the Great Works Dam and continued with other dams. This project aimed to restore fish passage and improve habitat for species like Atlantic salmon, which had been severely impacted by the dams.

The impact of dams to oxygen levels is perhaps one of the lesser-known, but most dire consequences of these structures. When vegetation and soil are submerged by reservoirs created by dams, they decompose without oxygen, a process that produces carbon dioxide and methane. The gasses that build up are then released into the atmosphere, either directly from the water surface or through dam turbines.

In the Himalayan country of Bhutan, which relies heavily on hydroelectric power, methane emissions from submerged vegetation have been linked to the melt on glaciers, causing concerns of disastrous flooding, and led to the power plants run on a much lower capacity than its full capability. Bhutan’s situation is far from an anomaly: a global study on reservoirs across the world, many of which were created as a result of dam constructions, are responsible for between 6-8% of anthropogenic methane emissions

The most serious impact, and the most significant environmental challenge to the large hydroelectric power plants in the form of dams, are the risks of Glacial Lake Outburst Floods (GLOFs) and dam failures. GLOFs occur when the natural dam containing a glacial lake fails, releasing large volumes of water downstream, often impacting hydropower infrastructure. With climate change accelerating the melting of glaciers as a result of greenhouse gas emissions, the concern has become even graver.

There are a lot more dams than we think, many of which are no longer serving as functional hydroelectric power plants and are way past their expected lifespan. There are more than 91,000 dams in the United States alone, most of which were built more than 50 years ago, and over 2,300 of them are under “high-hazard-potential,” according to the American Society of Civil Engineers.

Another variation on the impoundment system is pumped storage hydropower (PSH), which provides a more flexible source of energy to meet varying demands. They consist of two reservoirs at different elevations, connected by pipes or tunnels. During times of low electricity demand (often nights or weekends), excess electricity from the grid is used to pump water from the lower to the upper reservoir, effectively storing energy.

One of the advantages of pumped storage hydropower (PSH) is its ability to respond quickly to changes in electricity demand. Unlike some other renewable energy sources that can take time to ramp up production, PSH can typically begin generating electricity within minutes of a demand spike.

When electricity demand increases, the water stored in the upper reservoir is released through turbines. This process is quick because the system relies on gravity to allow the water to flow back down to the lower reservoir, which can happen almost instantaneously.

The turbines that generate electricity are connected directly to the water flow, allowing them to spin and produce power as soon as water is released. Since PSH systems are already set up to generate electricity at a moment's notice, they can adjust their output rapidly in response to real-time changes in demand. This rapid response capability makes it invaluable for grid stability, especially as more intermittent energy sources like wind and solar are integrated into the energy mix.

One of the most famous pumped storage hydropower (PSH) facilities is the Bath County Pumped Storage Station in Virginia, USA. It's one of the largest PSH plants in the world, with a total capacity of around 3,000 megawatts. The facility features two large reservoirs and plays a critical role in balancing energy supply and demand for the region, storing excess energy during low demand periods and generating electricity when demand is high. Bath County is often cited as a key example of the effectiveness of pumped storage in enhancing grid reliability and supporting renewable energy integration

In this way, PSH acts as a giant battery, helping to balance electricity supply and demand. PSH is the largest form of grid energy storage available today, accounting for over 90% of global storage capacity. Additionally, many PSH facilities can operate efficiently for decades, with some even exceeding 50 years of service, demonstrating their long-term viability as a key component of sustainable energy systems.

A Less Environmentally Damaging Hydropower System

As well as impoundment style hydroelectric plants with dams there are run-of-river systems. These are favored due to their lower environmental impact, compared to the more traditional impoundment style dams, as they maintain a more natural water flow.

They may have a small dam or weir to create a head and divert water to the turbines, but they do not significantly impede the river's flow. As a result, their power output is more dependent on seasonal conditions and may fluctuate more than impoundment facilities. They are often built in series along a river, forming a cascade of projects.

Because they don’t require large reservoirs, run-of-river systems are better for preserving local ecosystems and fish migration patterns as they do not need areas of land to be flooded. For example, in British Columbia, Canada, run-of-river projects can generate electricity while allowing salmon to navigate upstream, ensuring that vital wildlife populations are supported alongside renewable energy production.

The People Problem

The other issue with dam based systems is that if a dam structure fails due to architectural or engineering weaknesses, lack of maintenance, or natural disasters, it can lead to massive flooding, destruction of ecosystems, loss of human life and property and long-term, likely irreversible environmental degradation.

The other issue is that as a result of building large-scale dams and creating reservoirs hundreds of thousands people across the world are displaced. It was estimated that nearly 80 million people have been displaced, or involuntarily settled, as a result of these types of dam construction projects.

For example, during the construction of the Three Gorges Dam in China, 1.2 million people across the Yangtze River were moved away from their homeland, as hundreds of towns and villages were submerged under water to create new reservoirs. These displacements not only uproot people physically but also lead to the loss of livelihoods and cultural identity.

Emerging New Hydroelectric Technologies

In recent years, as technologies have developed, other forms of hydropower constructions have emerged to challenge the conventional techniques and systems.

One of them is underground hydropower plants, which are built through excavation deep below the earth's surface, making use of underground water flows or reservoirs. The main components, such as the turbines, generators, transformers, and control systems, are housed in underground caverns, which are connected by tunnels to the water source and outlet. These plants channel water from a high-altitude reservoir through tunnels that lead to turbines located deep beneath the surface, generating electricity efficiently.

Notable examples include the Obervermuntwerk II in Austria, situated in the Montafon Valley. This facility achieves a capacity of about 110 megawatts as part of a larger hydroelectric system in the region. Similarly, the Huangdeng Pumped Storage Power Station in China utilizes underground caverns for its turbines and generators, enabling efficient energy storage and generation, crucial for balancing grid demands.

In the United States, the Glen Canyon Dam and Hells Canyon Dam incorporate underground elements that enhance their operational efficiency. The Glen Canyon facility features tunnels that direct water to its turbines, while Hells Canyon leverages underground infrastructure as part of its extensive hydroelectric project.

Additionally, Bhutan's Tala Hydroelectric Plant utilizes underground tunnels to transport water to its turbines deep within the mountains, boasting a significant installed capacity of about 1,020 megawatts. These plants exemplify how underground hydropower can effectively harness energy while minimizing surface disruption and maximizing efficiency.

Another emerging new hydropower technology are gravitational vortex energy power plants which represent an eco-friendly way of generating electricity from low-head water flows.

This technology works by creating a swirling vortex in a circular basin where water flows in, rotating a turbine located at the center of the vortex. The continuous motion of the vortex keeps the turbine spinning, generating energy even in smaller streams or rivers.

Examples of gravitational vortex energy applications include the Vortex Bladeless turbine being tested in Spain, which harnesses energy from both wind and water. Although primarily wind-focused, similar principles can be applied to vortex technology in water environments. Another project is the HydroVortex in Canada, which aims to demonstrate the efficiency of vortex turbines in various water conditions. As this technology matures, more projects could emerge, showcasing its potential for sustainable energy generation.

It’s All About the Turbines

The turbine is the most crucial component of a hydropower plant because it is the central mechanism that converts the energy of flowing or falling water into mechanical energy, which is then transformed into electricity. Without the turbine, the immense potential energy stored in water due to its flow or elevation would remain untapped.

There are two main types of hydropower turbines: impulse and reaction turbines. They differ in design and how they capture the energy from flowing water to generate electricity. The choice between these turbines depends on several factors, including the head (the height from which water falls), flow rate, and specific site conditions. A higher head usually means more potential energy, which can be converted into electricity more efficiently.

Impulse turbines work best in situations where water falls from a great height but has a relatively small volume. They convert the energy of a fast-moving jet of water, which hits the turbine's buckets or blades, causing the turbine to spin.

In contrast, reaction turbines are better suited for low-head, high-flow conditions because they can efficiently convert the energy from large volumes of water with less vertical drop. These turbines operate by utilizing both the pressure and velocity of the water to spin their blades. Water enters the turbine through a spiral casing, which guides the flow onto the turbine runner, allowing for effective energy conversion in situations where the water falls from a shorter height

As water flows through the runner, which is the rotating part of the turbine that converts water energy into mechanical energy, it causes the blades to rotate, generating electricity. Reaction turbines are often used in large hydroelectric projects with low head and high flow rates. The Francis turbine is versatile, suitable for various head and flow conditions. Kaplan turbines, with adjustable blades, are ideal for low-head, high-flow situations and are commonly found in run-of-the-river projects, where the natural river flow is harnessed without large dams or reservoirs.

The Benefits and Continued Success of Hydropower

One of hydropower’s most significant advantages is its renewable nature. Hydroelectric power is classified as a form of renewable energy because it relies on the natural water cycle, which is continuously replenished by solar energy. When the sun shines, it drives evaporation from the Earth's surface, forming clouds that eventually release precipitation. This precipitation flows back into rivers and streams, creating a continuous supply of water. However, it's the movement of this water—whether from flowing rivers or falling waterfalls—that is harnessed to generate electricity.

As long as this cycle continues and the water is in motion, hydropower remains a viable and renewable source of energy.

Unlike fossil fuels, which are finite and release greenhouse gasses when burned, hydroelectric power generates energy without diminishing water resources or producing emissions. In hydroelectric systems, water is not consumed or altered, making it a sustainable and clean energy source for the long term.

Reservoirs created by hydroelectric power plants store water during periods of low demand and release it when energy needs peak, ensuring a steady supply of electricity. Moreover, hydropower plants are highly efficient, with some facilities converting up to 90% of the available energy into electricity, a much higher rate than most other energy sources (such as the 17-20% in solar and the highly varied conversion rate among wind turbines).

As a result of the high rate of conversion, hydroelectric power provides critical support to the stability of electricity grids. Hydropower plants can adjust output rapidly, allowing them to respond to fluctuations in demand. This ability to ramp up or scale back water flow within minutes makes hydropower an ideal source for balancing electricity grids, especially as more intermittent renewable sources like wind and solar are integrated.

Additionally, pumped storage hydropower plants, which store energy by pumping water to a higher elevation and releasing it during peak demand, offer a highly effective way to store excess energy, helping to ensure a reliable electricity supply even when renewable sources are less productive.

Many hydroelectric facilities are multipurpose, providing benefits such as flood control, irrigation, and recreation. Reservoirs created by dams can prevent floods by regulating water flow and storing excess water, which can also be used for agricultural purposes during dry periods. These reservoirs often become recreational areas (for example, Lake Mead was formed as a result of the Hoover Dam), supporting activities like boating and fishing, which can further boost local economies.

What does Hydropower’s Future Look Like?

The future of hydropower is shaped by both its immense potential and the challenges it faces in the context of climate change and sustainable development. Its status as the world’s largest source of renewable energy is unlikely to change in the near future and continues to exist as an enduring and stable option of energy supply, which means countries striving to meet decarbonization targets will still vye for hydropower to do so.

However, achieving these goals will require significant investments in new hydropower capacity, especially in developing regions where untapped resources remain abundant. According to the International Renewable Energy Agency (IRENA), hydropower's installed capacity may need to more than double by 2050 to meet the global climate target of 1.5 degrees celsius. This will demand not only massive financial investments, but also technological innovations and policy reforms to ensure the sustainability and resilience of future projects.

Another significant trend shaping the future of hydropower is the shift toward smaller, more sustainable projects. Large-scale dams are known for their environmental and social impacts, including the displacement of communities and the damage of local ecosystems. In response to these concerns, there is growing interest in low-impact hydropower technologies, such as hydrokinetic turbines and micro-hydropower plants, which generate energy without the need for large reservoirs or significant alterations to river systems.

In recent years, solar panels have been combined with the reservoirs on impoundment facilities to provide spaces to generate electricity through more diverse means. The photovoltaic panels, which float on the top of the reservoir overlooking the dam, can balance each other to meet the demand when there isn’t enough waterflow to generate the adequate amount of electricity through the dams alone. One research from the Renewable Energy journal estimates that if this pairing is implemented across the world, they will be able to drastically reduce the cost of solar electricity and meet 40% of the global electricity demand.

Threats to Hydropower

Hydropower generation relies on predictable water flows, which are ironically, and increasingly, threatened by changing precipitation patterns, glacial melt, and extreme weather events. In many regions, such as the Himalayas and the Amazon Basin, climate change is causing both increased flood risks and prolonged droughts, which can severely disrupt hydropower production.

The variability of water availability caused by climate change could make hydropower less reliable in certain areas, particularly in regions where glacial meltwater or seasonal rainfall is a critical component of river flow. Researchers suggest the incorporation of climate resilience models into their design and operation, including adaptive reservoir management and the use of hybrid systems that integrate solar or wind energy.

Hydropower’s future depends on effectively addressing the significant environmental and social challenges associated with its construction. As a crucial player in the transition to renewable energy, hydropower must adapt to these emerging issues while continuing to play an essential role in our energy systems. The success of the global shift toward renewable energy will rely on how well hydropower navigates these challenges.

Tags: explainer, sustainability

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The Heat is On: Harnessing Nature’s Underground Oven

Allen Huang — Thu, 17 Oct 2024 13:13:16 +0000

EARTHDAY Explainers - V

The Heat is On: Harnessing Nature’s Underground Oven

By Allen Huang

It’s World Geothermal Energy Day on October 17 - probably not a date you have marked in your calendar, vying with Halloween but perhaps we do need to give this latent energy source a lot more love.

In the quest for renewable energy, we’ve built massive dams, constructed towering wind turbines, and covered fields with solar panels. Yet, amidst these efforts, are we overlooking a powerful energy source right beneath our feet? Geothermal energy remains largely untapped, waiting to be harnessed.

The Science Beneath Our Feet: Understanding Geothermal Energy

Perhaps the simplest and cleanest description of geothermal comes from the U.S. Energy Information Administration (EIA): Geothermal energy arises from the decay of radioactive particles in the Earth’s core—specifically uranium, thorium, and potassium. This decay generates immense heat, creating a continuous 'thermal engine' that we can tap into for generating heat and electricity

When you witness lava flowing from a volcano or a geyser erupting with steam and hot water, you’re observing the powerful forces of natural geothermal processes at work.

Volcanic eruptions occur when magma—molten rock formed from intense heat and pressure deep within the Earth—forces its way to the surface. This magma originates from the melting of rocks in the mantle, which occurs due to the Earth’s core generating immense heat from decaying uranium, potassium and thorium. As our planet’s tectonic plates move and shift, the magma can erupt through cracks in the Earth’s crust - volcanoes!

Geysers, on the other hand, are formed from underground water reservoirs near these molten rocks, and they erupt when the water is boiled into steam. a well-known sight all over the world from Yellowstone park in the U.S to the Great Geysir in Iceland to El Tatio, in Chile.

A Brief History of Human Use

Geothermal has been used by human beings in one form or another for thousands of years; ten thousand years ago it was believed that American Paleo-Indians used the boiling water from natural hot springs to cook and clean. In fact geothermally created natural hot springs have been utilized all over the world throughout human history, including in China, and by the Roman Empire. By the Second Industrial Revolution, engineers had managed to harness geothermal energy to heat the inside of buildings with specially designed hot water pipelines. These pipelines were first used in Boise, Idaho, in a facility opened in 1892 and which still runs today to power the State House and City Hall.

The first industrial application of geothermal energy for electricity came from the small village of Larderello in Tuscany, Italy. In 1904, Italian engineer Piero Ginori Conti used the natural steam from the geothermal to power an engine, and they soon built a commercial power station entirely based on geothermal energy.

After the end of World War II, many more countries have seized on the opportunity to develop their own geothermal facilities. The Geysers, the first geothermal power plant in the United States, located in the Mayacamas Mountains in Northern California, was built in 1960. Today, it remains the largest geothermal power plant system in the world, with 725 megawatts of installed generating capacity, which is enough to generate the entire city of San Francisco.

It is clear that geothermal energy has been harnessed by humans for millennia, but today, advancements in technology are unlocking geothermal's true potential, which is to create electricity, and not just provide a ton of hot water!

Why Is Geothermal a Renewable Energy?

"Geothermal energy is renewable because the Earth has retained a huge amount of the heat energy that was generated during the formation of the planet. In addition, heat is continuously produced by decay of radioactive elements within the Earth. The amount of heat within the Earth, and the amount that is lost through natural processes (e.g. volcanic activity, conduction/radiation to the atmosphere), are much, much more than the amount of heat lost through geothermal energy production….Over time, it is commonly necessary to drill additional wells in order to maintain energy production as temperatures and/or reservoir fluid pressures decline." Drew L. Siler, PhD, Geothermal Geologist, American GeoSciences Institute

As a renewable energy, the most significant benefit for geothermal energy is the reduced level of greenhouse gas emissions (GHG) it is responsible for in contrast with fossil fuels, when used to generate electricity. On average, geothermal electricity power plants, produce 122 grams of CO2 per kilowatt-hour (g/kWh), which is about 73% lower than typical natural gas power plant emissions (450 g/kWh) and 86-90% lower than coal-fired power plants (900-1300 g/kWh).

How is Geothermal Energy Extracted & Turned Into Electricity

The conventional extraction of geothermal energy involves drilling wells into geothermal reservoirs, typically located 1–5 kilometers beneath the surface.

These wells tap into both low-temperature resources (below 150°C) and high-temperature resources (above 150°C). Drilling geothermal wells requires specially designed rotary drilling equipment to handle the harder rock formations and higher temperatures encountered, unlike conventional oil and gas wells.

Once the wells are completed, geothermal fluids—hot water, steam, or a mixture of both—are extracted from the reservoir and brought to the surface through a system of pipelines. These fluids rise through the well due to pressure differences and natural convection.

It’s the steam created which can be used directly to drive turbines for electricity generation, while the hot water can be sent to a heat exchanger to transfer its thermal energy.

How Many Methods Are There To Turn Heat into Electricity?

Currently, there are four separate methods to transform the extracted geothermal power from the crust for electricity generation. The conventional extraction methods, known as dry steam, flash steam, and binary-cycle, make up the majority of the traditional geothermal power generation across the world. In recent years, enhanced geothermal systems (EGS), which involves human made inductions of geothermal energy through drilling wells and creating reservoirs, has made geothermal power more widely available.

Dry Steam Power Plants utilize steam from geothermal reservoirs to directly turn turbine generators. In this type of system, superheated steam is drawn from underground reservoirs that naturally contain minimal water. Since the steam emerges from the Earth in a "dry" state, with little or no liquid water mixed in, it can be piped directly to a steam turbine, which spins to generate electricity.

This method is highly efficient because there is no need to first separate water from steam or flash the steam into existence. This method is suitable for geothermal fields that produce dry steam with minimal water content, such as The Geysers in Northern California. However, due to rigorous requirements for suitability, dry steam geothermal fields are rare and only exist in a few locations worldwide.

Flash Steam Power Plants extract high-pressure hot water from deep within the Earth and convert it to steam by reducing the pressure in a process known as "flashing." In a flash steam plant, geothermal fluid is pumped from underground reservoirs that contain both hot water and steam, typically at temperatures exceeding 182°C (360°F). As the pressurized water is brought to the surface, it enters a flash tank, where a sudden reduction in pressure causes some of the water to vaporize, or "flash," into steam. This steam is then used to drive turbine generators, producing electricity.

Flash steam plants are highly versatile because they can work with geothermal reservoirs that contain a mixture of steam and water, unlike dry steam plants which require pure steam. Additionally, any liquid water left after the flashing process can be injected back into the Earth or used in a secondary flash tank for additional energy production. Flash steam power plants are the most common type of geothermal plant because they can efficiently harness high-temperature geothermal resources, which are found in a wider range of geothermal fields compared to dry steam reservoirs.

Binary-Cycle Power Plants transfer heat from geothermal water to a secondary fluid with a lower boiling point, usually easily vaporizable organic compounds like hydrocarbons, through a heat exchanger. The vaporized secondary fluid drives the turbines. This method is highly effective for lower temperature resources between 107°C (225°F) and 182°C (360°F) and operates in a closed-loop system, keeping the geothermal water and secondary fluid separate.

This minimizes emissions and prevents the release of harmful gasses, making it a cleaner energy solution compared to other geothermal technologies. Due to its ability to harness moderate-temperature geothermal resources, binary-cycle plants can be used in a wider range of locations. A prominent example of a binary-cycle power plant is the Chena Hot Springs Plant in Alaska, which operates efficiently using relatively low-temperature geothermal resources.

Enhanced Geothermal Systems (EGS), also known as Hot Dry Rock (HDR), artificially stimulate and enhance geothermal reservoirs by injecting water to create fractures in hot dry rock formations in a process known as stimulation. This method expands geothermal energy potential to areas without natural hydrothermal resources, usually deeper beneath the surface, and could vastly increase the accessible geothermal energy worldwide.

It’s important to point out that, unlike fracking, Enhanced Geothermal Systems (EGS) stimulation, which is used to generate geothermal energy, typically uses much less water with much smaller pressures. In many cases, the water is recycled within a closed-loop system, minimizing waste and contamination risks. Additionally, EGS does not involve extracting fossil fuels or producing harmful byproducts like methane, which further reduces the risk of water pollution.

Plus Geothermal Energy Can Still Be Used for Heating and Cooling

When not being used to generate electricity, the extracted geothermal energy can be turned into a steady source for heating and cooling different places, including factories, agriculture fields, as well as industrial factories. Applying geothermal energy relies on two methods: direct use applications and geothermal heat pumps (GHPs), replacing the fossil fuels of natural gas and coal that have been traditionally used to generate heat.

Direct use applications involve tapping into geothermal reservoirs that provide naturally heated water or steam from the Earth. This method requires minimal energy conversion, making it incredibly efficient. The geothermal water, typically ranging from 70°F to 300°F (20°C to 150°C), can be used directly for various heating applications. When the water can exceed the atmospheric boiling point of 212°F (100°C) due to the high pressure deep underground, making it an even more versatile energy source.

One of the most common uses of direct geothermal energy is for building heating. Geothermal fluids are piped through a heat exchanger to warm buildings through radiant floor systems or radiators. In some areas, entire neighborhoods benefit from district heating systems, where one geothermal source supplies heat to multiple buildings.

Geothermal energy is also used in agriculture, where it provides warmth to greenhouses, extending the growing season and improving crop yields. Aquaculture facilities use it to maintain ideal water temperatures for fish farming, which can boost growth rates and reduce energy costs. In industrial processes, geothermal heat is employed in various applications, such as food dehydration, milk pasteurization, and lumber drying, providing an affordable and reliable heat source.

While direct use applications rely on naturally hot water, geothermal heat pumps (GHPs), also known as ground-source heat pumps, use the Earth’s stable underground temperature for both heating and cooling. The ground or groundwater maintains a constant temperature year-round, which makes it an ideal source of heat exchange.

In the winter, GHPs extract heat from the ground and transfer it into buildings. A water-based solution circulates through a series of pipes, called a "ground loop," buried below the surface. This fluid absorbs heat from the Earth, and the GHP system uses this heat to warm the building. In the summer, the process is reversed. The GHP extracts heat from the building and releases it into the cooler ground, providing efficient cooling.

So How ‘Hot’ Can Geothermal Heat Actually Get?

Just how much heat can be produced by geothermal depends on something called the geothermal gradient. This is the rate at which the Earth's temperature rises with increasing depth—typically about 25–30 degrees celsius per kilometer down into the crust.

Understanding geothermal energy requires an idea of the earth’s basic structure and composition. So here goes: below our feet lies the Earth's crust, averaging about 30–70 kilometers thick on land and 5–10 kilometers thick under the oceans.

Beneath the crust is the mantle, extending down to about 2,900 kilometers, composed of hot, semi-solid silicate rocks rich in iron and magnesium. The core lies even deeper, with temperatures estimated between 5,000 and 6,000 degrees Celsius, comparable to the surface temperature of the Sun.

Image by brgfx on Freepik

Other Reasons to Love Geothermal

Aside from contributing less GHG, which helps to mitigate climate change, unlike solar and wind, which depend on the weather of the day to function properly, geothermal energy is not dependent on weather conditions.

No matter the method of generation, geothermal energy is based on the constant heat generated from the Earth’s core, making it a reliable source of base-load electricity that operates 24/7, regardless of external weather conditions.

Most energy power plants, such as coal or nuclear power plants, require large volumes of water for cooling, but geothermal plants, especially those using dry-cooling systems, can operate with minimal water use. This reduction in water dependency not only preserves vital freshwater resources but also helps avoid the negative environmental impacts associated with the heavy water usage in other energy sectors.

As they both use similar technologies and rely on drilling, some abandoned oil and natural gas wells in the West have been retrofitted to become sites for geothermal production. The abandoned wells are surveyed, evaluated, reconfigured, and then used to establish a heat exchange system to develop into a new geothermal power plant.

In recent years, the Department of Energy has actively pursued the development of geothermal energy from abandoned oil wells through its Geothermal Technologies Office (GTO) and the Wells of Opportunity (WOO) initiative. The WOO initiative funds various projects across the United States, from improving well permeability in Nevada to harvesting waste heat from existing wells in Texas and California. By tapping into the millions of inactive wells across America, this approach significantly reduces expensive drilling costs, and addresses environmental concerns by giving new life to abandoned infrastructure.

The economic benefits of geothermal energy extend beyond its operational efficiencies. Take heat pumps used for residential heating for example, compared to conventional HVAC systems, geothermal heat pumps can reduce energy consumption by 25% to 50%, which can become a full replacement of HVACs in many climates. They are popular in both residential and commercial buildings, offering a sustainable alternative for heating and cooling. Additionally, geothermal heat pumps have long operational life spans—often lasting upwards of 25 years—and require less maintenance, as they are protected from outdoor weather conditions and do not rely on fuel combustion.

Reasons To Love Less About Geothermal

As geothermal plants are usually built near regions closer to the earth’s crust, which are mostly situated on fault lines and are susceptible to seismic activity, the drilling, injection and extraction of fluids has been a long held concern from some scientists over the feasibility and safety of their widespread usage.

The development of enhanced geothermal systems (EGS) has raised further concerns about induced seismicity, which are earthquakes triggered by human activities. As EGS involves injecting fluids into hot dry rock reservoirs deep underground, this can change stress fields and cause the rock to fracture, potentially leading to seismic instability.
A study by the National Academies of Sciences, Engineering, and Medicine titled "Induced Seismicity Potential in Energy Technologies" concluded that geothermal energy has a low likelihood of causing noticeable earthquakes. This is because the process involves both injecting fluid into and extracting it from underground reservoirs.

The practice of EGS in the United States is still under the experimental phase. The Frontier Observatory for Research in Geothermal Energy (FORGE) is the only active site for EGS research and development, and it is still being mostly used to test the potential of EGS instead of widespread utility implementation.

When fluid is injected, it increases pore pressure which reduces the effective stress clamping faults together. This pore pressure diffusion is one of the main mechanisms triggering injection-induced earthquakes. Temperature changes from injecting cold fluids into hot rock also play a role by causing thermoelastic stress changes.

Additionally, geochemical reactions between injected fluids and reservoir rocks can weaken faults through stress corrosion. The mechanisms of injection-induced seismicity are complex, involving coupled thermo-hydro-mechanical-chemical (THMC) processes, making it difficult to calculate.

While most injection-induced earthquakes tend to be small (below magnitude 3), occasionally larger events do occur, such as a magnitude 5.5 quake in Pohang, South Korea in 2017 associated with an EGS project. Concerns about such damaging induced seismicity have led to some EGS projects being canceled in the past. In the aftermath of the Pohang earthquake, scientists worked to develop solutions to mitigate risks in the future. They found that pressure from fluid injections had activated a previously unknown fault, leading to the large quake. To address this, researchers proposed improved monitoring techniques to detect hidden faults, along with advanced models to predict how injections alter subsurface stresses.

They also recommended implementing adaptive "traffic light" systems that can rapidly modify injection strategies if worrying seismic activity emerges. With such efforts, the goal is to enable safer EGS development going forward, as EGS has been widely shown to be the leader in the next generation of geothermal applications.

Aside from induced seismic activity water use, geothermal power plants can often require significant amounts of water for cooling and steam production too, which can strain local water resources, even though many geothermal power plants use close-loops to encourage water circulation.

Plus geothermal plants require substantial land for drilling and infrastructure, which can disrupt local ecosystems, biodiversity and communities; however, research has suggested that such land use is still relatively insignificant compared to development in oil and natural gas.

The upfront costs of geothermal projects, particularly for exploration and drilling, can also be significant; IRENA estimates that it costs $1,870 to $5,050 per kilowatt (kW) to construct a geothermal plant, with the cost heavily dependent on the geological conditions of the sites themselves. In comparison, larger wind farms cost only about $1,500 per kW to construct. This can sometimes make it harder to attract investment compared to more other renewable sources like wind and solar.

Geothermal Energy’s Current Status in The U.S

Currently, geothermal energy is hugely underutilized in the U.S., with the vast majority of heating demand—about 60%—being met by fossil fuels such as natural gas, propane, and oil, which accounts for 40% of total greenhouse gas emissions in the country. Geothermal heating systems, including ground-source heat pumps and district heating, account for only a small fraction of the U.S. heating market; according to the IEA, there are only 1.7 million geothermal heat pumps are used across the United States, and only 40% of them are used for residential purposes, which is 0.5% of all American households. The Department of Energy, using money allocated from the Inflation Reduction Act, has promised to install 28 million geothermal heat pumps across the country.

According to the U.S. Department of Energy, almost 4 gigawatts of electricity is produced using geothermal technologies, which is enough to power 3 million homes. While this is only 0.4% of all electricity generation, it remains the most amount of geothermal electricity generated in the world, with most of the current geothermal power plants located in California and Nevada.

The U.S. government has been seizing the opportunity of renewable energy development to aggressively expand the development of geothermal power plants in recent years. This process was enacted using two different means, both through congressional legislation and through investment plans from the federal government.

In Congress, after the passage of a similar bill in the House of Representatives, a group of bipartisan Senators have introduced the Geothermal Energy Optimization (GEO) Act of 2024 to streamline the permitting process in the same way it was done in the past to oil and gas permitting.

The current permit process, which follows strict guidelines, would result in reviews from multiple agencies and takes nearly a decade before any construction could even begin. The proposed changes in the bill will establish geothermal inspectors (ombudsmen) and strike teams, providing technical assistance and mediation for dispute resolution, ensuring efficient project development, as well as setting new targets for geothermal leasing on federal land, requiring the Bureau of Land Management to hold leasing auctions more frequently.

While most energy projects on federal lands, managed by the Department of Interior’s Bureau of Land Management (BLM) are strictly reviewed and regulated, the BLM has recently expedited the process of geothermal permitting through categorical exclusion of the National Environmental Policy Act (NEPA). In their press release to expedite geothermal permitting on federal lands, Tracy Stone-Manning, the director of BLM, called the technology “one of the technologies that can move our country toward a clean energy future.”

Map of the geothermal resources in the United States, source: NREL

Following measures from Congress and the BLM, the Department of Energy has also released a new report to assess the practicality of massive commercial expansion of geothermal energy in the United States. With the money provided through the Inflation Reduction Act and the Bipartisan Infrastructure Law, the Department estimates that there will be potential to expand geothermal power to 90 gigawatts by 2050, a 22-fold increase from current capacity.

To reach what the report describes as a “liftoff,” the department needs to demonstrate market potential through successful deployment in greenfield conditions and validation projects across 5-10 different geologic settings using 20-25 billion dollars of startup investment. Once the startup investment is proven to be successful, large-scale geothermal projects that could utilize hundreds of billions of dollars for more widespread usage will be constructed across the country.

Global Hotspots: How Countries are Harnessing Geothermal Power

While the U.S. leads in geothermal electricity generation, countries like Iceland are harnessing this resource to heat 90% of its homes and generate 30% of its electricity. The Hellisheiði and Nesjavallavirkjun power plants are examples of large-scale geothermal facilities.

Kenya is a leader in geothermal energy in Africa and is one of the top producers globally. The Olkaria Geothermal Plant, part of the Hell's Gate National Park, is a major facility contributing to the national grid, providing about 40% of the country's electricity. The East African Rift System provides significant geothermal potential in the region.

Ethiopia is exploring its geothermal resources, particularly in the East African Rift. The Aluto-Langano geothermal plant has been operational since 1998, and more projects are in development to harness the country's geothermal potential.

Italy has been the home to the world’s first geothermal power plant in Larderello, and it continues to harness geothermal energy for its energy grid, producing around 4% of its electricity from geothermal sources.

Many countries in Latin America is also looking to geothermal energy. For example, Mexico is a significant player, primarily in the Cerro Prieto Geothermal Power Station, one of the largest geothermal plants in the world. The country is actively expanding its geothermal projects as part of its commitment to renewable energy.

Chile is exploring its geothermal potential, particularly in the Andean region. While still developing its geothermal resources, the country has great potential due to its volcanic activity.

Australia is beginning to tap into its geothermal potential, especially in regions like the Cooper Basin and the hot rocks geothermal resource in South Australia. Although geothermal energy contributes minimally to Australia’s energy mix currently, there is significant interest and potential for growth, particularly with enhanced geothermal systems (EGS).

Globally, geothermal energy is gaining traction, proving its worth as a reliable renewable source.

Geothermal’s Future

Geothermal energy is poised to emerge as a crucial player in the global transition to clean energy. With its vast potential to significantly reduce greenhouse gas emissions, geothermal stands out as a reliable and sustainable resource. Unlike intermittent sources like wind and solar, geothermal offers consistent, base-load power generation, providing a stable energy supply regardless of weather conditions.

As technology advances and extraction methods improve, geothermal energy could play an even more pivotal role in diversifying the renewable energy portfolio. The ongoing development of Enhanced Geothermal Systems (EGS) opens up new possibilities, allowing us to tap into previously inaccessible geothermal resources, but it also requires drafting careful safety guidelines so it could prevent worsening seismic activity.

However, realizing this potential requires not only technological innovation but also supportive policies and investments. By fostering a regulatory environment that encourages environmentally sound geothermal exploration and development, governments can harness this underutilized resource.

With the right commitment and collaboration, geothermal energy could become as indispensable as wind and solar in our fight against climate change, driving us toward a cleaner, more sustainable future. The time to invest in geothermal is now—let’s unlock this powerful resource for generations to come.

Tags: explainer, sustainability

This article is free to republish on your web site, in your newsletter, magazine, newspaper, publications or blog. The imagery is cleared for use too. Please just keep the author’s name on the piece and that they are from EARTHDAY.ORG. Let us know if you re-publish so that we can try to acknowledge, tag or re post you! You can let us know via an email to davies@earthday.org or fielder@earthday.org.

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Blowin’ in the Wind

Allen Huang — Fri, 11 Oct 2024 12:00:38 +0000

EARTHDAY Explainers - IV

Blowin' in the Wind

By Allen Huang

The whirlwind of change is sweeping across the global energy landscape, and one of the clean energy sources at the forefront of this transformative journey is the rapidly expanding wind energy sector.

As the most recent report from the Global Wind Energy Council (GWEC), an international trade association representing the wind energy industry indicates, the industry has achieved its second most successful year to date in 2023, with installations increasing by an impressive 50% year-on-year.

Many countries around the world have harnessed this energy source with incredible results. Denmark, for example, has supplied 57.7% of their electricity through wind energy in 2023, reaching an all-time high. In Spain, wind energy accounts for nearly a quarter of electricity generation, reflecting significant investments in wind farms across the country.

The United States, with its vast landscapes, harnesses wind power extensively, particularly in states like Texas and Iowa, where wind turbines generate a substantial portion of their energy. Currently, wind accounts for 10% of total energy output and 22% of new electricity capacity, which, along with existing infrastructure, has the ability to generate enough power to 43 million households.

Meanwhile, Germany's robust wind energy sector contributes significantly to its ambitious climate goals, with wind farms playing a crucial role in reducing greenhouse gas emissions. It has overtaken coal, historically the most crucial source of energy, to be the largest source of electricity in 2023. These countries exemplify the global shift towards wind energy as a reliable and eco-friendly power source.

As nearly 200 countries set ambitious targets and pledge to triple renewable energy capacity by 2030, wind power is poised to play a critical role in reshaping our energy systems and paving the way for a net-zero future. Which is why EARTHDAY.ORG set the Earth Day Theme for 2025 as Our Power, Our Planet. With the specific aim of tripling renewable electricity generation by 2030.

How Do We Harness Wind Energy?

Wind energy harnesses the kinetic energy of moving air to generate electricity using large wind turbines. These turbines, which can have either horizontal or vertical axes, are equipped with blades that capture the wind’s energy. As the wind blows, it pushes against the blades, causing them to spin. This spinning motion turns the rotor, which converts the wind's kinetic energy into mechanical energy.

The mechanical energy from the spinning rotor is then transferred to a generator through a direct-drive system. The direct-drive system connects the spinning blades directly to the generator, skipping the need for gears, so there is less chance of things breaking. This setup allows the turbine to work more smoothly and consequently requires less maintenance because it has fewer parts that can break.

The generator, housed within something called the nacelle—a protective casing at the top of the turbine—converts the mechanical energy into electrical energy. The nacelle safeguards the turbine's crucial components and ensures efficient energy production.

A Wind turbine nacelle cross-section. (www.researchgate.net)

The Height Factor

The amount of power available in the wind, measured in watts, is proportional to the cube of the wind speed. This means that if the wind speed doubles at a constant rate, the amount of power available in the wind increases by eight times (because 2³ is 2 x 2 x 2 which is 8). So, even a small increase in wind speed can lead to a big increase in the amount of power you can get from the wind.

This consequently means that locations with high average wind speeds have significantly greater wind power potential than areas with lower average speeds.

Wind speed also typically increases with height above ground, so taller wind turbines can capture more energy. Why? Well because the air near the ground is slowed down by friction with surfaces like trees and buildings. As you go higher, this friction decreases as there’s essentially less to slow wind down and the wind flows more smoothly and quickly.

Therefore, taller wind turbines can capture these stronger, smoother and steadier winds at higher altitudes, allowing them to generate more energy compared to shorter turbines which are closer to the ground and the more obstructed wind.

Wind turbines are best situated in locations where the annual average wind speed reaches a minimum of 9 miles per hour (mph), equivalent to 4.0 meters per second (m/s), for small-scale wind turbines.

For utility-scale wind turbines, the ideal annual average wind speed should be at least 13 mph, or 5.8 m/s. In this context, "utility-scale" refers to large wind turbines used for generating electricity on a large scale, typically connected to the power grid and providing energy for widespread use. These are contrasted with "small-scale" wind turbines, which are used for local or individual applications, such as powering homes or small businesses.

Onshore Vs Offshore

There are two distinct ways that wind turbines have been used to generate electricity in large capacities, often referred to as “wind farms.”

Onshore wind farms are located on land, while offshore wind farms are situated in bodies of water, usually at sea. Both technologies have seen significant growth and advancement in recent years as countries go through their renewable energy transition.

Onshore wind energy has a longer history, with wind technology being installed on land for over a thousand years. In contrast, offshore wind energy is a more recent development, with the first offshore wind farm being built in 1991 in Denmark.

For onshore wind energy, once the electricity is produced, it is carried down through power cables inside the tower to a transformer at the base. The transformer increases the voltage of the electricity, ensuring that it can be transmitted efficiently over long distances to the power grid.

From the transformer, the electricity is fed into a switchyard, where it enters the broader electrical grid and is distributed to consumers. Onshore wind farms are often less expensive to build and maintain compared to offshore farms, making them a practical choice for certain places.

Despite its shorter history, offshore wind has seen rapid growth due to several advantages it offers over onshore wind. Offshore wind speeds tend to be higher and more consistent than on land, and the vast open spaces of the ocean allow for the installation of larger turbines and wind farms.

One of the key advantages of offshore wind energy is the size and scale of the turbines. With fewer space constraints compared to land-based wind farms, offshore installations can support larger rotor diameters and taller towers. This allows them to capture more wind energy, maximizing the potential output.

These turbines are anchored to the seabed by foundations, which vary depending on the water's depth and environmental conditions. Typically, offshore wind farms are located several miles from shore, taking advantage of stronger wind patterns while minimizing their visual and noise impact on nearby communities.

The electricity generated by offshore wind turbines is transmitted to shore through a network of connecting cables. These cables run along the seabed and link the turbines to an offshore substation, and from there, the electricity is sent to an onshore substation, where it is fed into the national power grid.

Energy Storage

However, only a portion of the total power in the wind can actually be captured by a wind turbine. The theoretical maximum, known as the Betz limit, is 59.3% of the wind's power. Actual wind turbines operate at lower efficiencies, typically 27-44% offshore and 30-35% onshore, due to various aerodynamic and mechanical losses.

Modern utility-scale wind turbines are usually horizontal axis machines with three blades. The blades use airfoil shapes to generate lift forces that cause the rotor to spin. Careful design of the blade shape and materials is critical for maximizing power output while minimizing loads and noise.

While wind is an abundant resource globally, it is intermittent. Wind speeds fluctuate over multiple time scales, so wind farms do not provide steady power output like conventional fossil fuel or nuclear plants.

To address this challenge, excess electricity generated during periods of high wind can be captured and stored in batteries. These batteries, such as lithium-ion or flow batteries, store the surplus energy as chemical energy.

When wind production drops or stops, the stored energy is released from the batteries and supplied to the grid, providing a more consistent and reliable power source. This method of energy storage helps to smooth out the fluctuations in wind power and ensures a steady electricity supply, even when the wind isn’t blowing.

Lithium-ion batteries are the most popular choice due to their high energy density and efficiency, making them suitable for both residential solar storage and large-scale grid applications.

For larger projects, flow batteries are often used; these store energy in liquid electrolytes and can be scaled up easily, offering long cycle life and robust performance.

In some cases, lead-acid batteries, though less efficient and with shorter lifespans, are still used due to their lower cost and established technology.

Sodium-sulfur batteries are another option, known for their high energy density and durability, making them ideal for stabilizing the grid in large-scale storage systems.

Emerging zinc-air batteries are also being explored for their high energy density and potential cost benefits, though they are still under development for large-scale use. Each type of battery helps address the variability of wind energy by storing excess power and providing a steady supply when wind conditions are less favorable.

Batteries are an essential component of the wind energy business but there are several challenges. They can be costly, with advanced technologies like lithium-ion batteries requiring significant investment, though prices are gradually decreasing.

Additionally, batteries have a limited lifespan, with their performance degrading after a certain number of charge and discharge cycles, necessitating eventual replacement.

Energy density refers to the amount of energy that can be stored in a given system or material per unit of volume or mass. Higher energy density means that more energy can be stored in a smaller or lighter space. The energy density of batteries, although improving, may still fall short compared to other storage methods, limiting their effectiveness for large-scale applications. Scaling up the density of the batteries, while appealing in theory, run amok to the issue of high cost and short lifespans.

There are other energy storage methods that are better suited for large-scale use. These methods include pumped hydroelectric storage, which stores energy by pumping water uphill to a reservoir and releasing it to generate electricity when needed, and compressed air energy storage, which stores energy by compressing air in underground caverns and releasing it to drive turbines.

Environmental concerns also arise from the production and disposal of batteries, including the impact of mining raw materials and recycling challenges.

Temperature sensitivity affects battery performance, as extreme conditions can degrade efficiency and longevity. Moreover, the rate at which batteries can be charged or discharged may not always meet the rapid demands of the energy grid, and large-scale systems require substantial physical space. Addressing these issues is crucial for enhancing the viability and sustainability of battery storage for wind energy.

The US Industry Blows Hard

According to the U.S. Energy Information Administration (EIA), the majority of U.S. wind electricity generation capacity is located in the middle of the country in states such as Texas and Oklahoma.

In 2023, The five states that produced the most electricity from wind in 2023 were Texas, Iowa, Oklahoma, Kansas, and Illinois. Together, these states accounted for approximately 59% of the total U.S. wind electricity generation that year.

In the U.S., the average household uses about 10,600 kWh of electricity per year. Given that the total U.S. wind electricity generation from the five top states in 2023 was about 250 billion kWh, we can calculate that the wind electricity from these five states alone could power approximately 23.6 million homes in the U.S. for an entire year, which represent 18% of all US homes.

The Global Growth is Palpable

It is not just the U.S that is seeing the light when it comes to wind.

The GWEC’s 2024 report indicates that both onshore and offshore wind have been experiencing significant growth globally, creating a 50% year-on-year increase from 2022 to 2023. Onshore wind installations surpassed the 100 gigawatts (GW) milestone for the first time, with 105.8 GW of new capacity added, while offshore wind had its second-highest year, with 10.8 GW of new installations.

By the end of 2023, the global cumulative wind power capacity reached 1,021 GW, a 13% increase from the previous year. Onshore wind accounted for the majority of this capacity, with 945 GW installed, representing a 12% year-on-year growth. Offshore wind capacity also grew, reaching a total of 75.2 GW globally.

Technological advancements have played a significant role in the growth of both onshore and offshore wind. Modern wind turbines are becoming increasingly larger and more efficient, with higher hub heights and longer rotor diameters. These improvements have led to increased energy output and lower costs.

In 2021, the average rotor diameter for offshore wind turbines reached 160 meters, a 43% increase from 2010. Onshore wind turbines have also seen significant growth, with the average rotor diameter increasing by 91% in China and 72% in Brazil between 2010 and 2021.

The world's largest wind turbine, the Goldwind GWH252-16MW, has set a new record for the most power produced by a single turbine in a day. Located offshore from Fujian Province, China, this gigantic turbine has a 252-meter (826.8 feet) diameter. In windy conditions, this one turbine alone can generate more than 380 megawatt hours (MWh) in a day, which is enough to power 170,000 homes.

Electricity Generated by Wind Energy is Getting Cheaper

The increasing adoption of wind energy is driven by a combination of factors, including falling costs, supportive government policies, and the urgent need to combat climate change. Many countries have set ambitious renewable energy targets, with wind power expected to play a crucial role in meeting these goals. According to the International Renewable Energy Agency (IRENA), wind energy could supply 35% of global electricity demand by 2050.

Wind Energy’s Issues

While wind energy boasts a smaller carbon footprint compared to fossil fuels, it is not without its own set of environmental challenges.

For one thing, we don’t see wind turbines in regular households as often as we see solar panels, for a good reason. Commercial wind turbines cost about 2.6-4 million dollars to build and more than 40,000 dollars to operate and manage, while they require 25-40 acres of land to be built and stand, which would be nearly impossible for most residential households to operate.

Residential wind turbines do exist, but according to industry estimates, the cost of installing a small wind turbine can range from 15,000 dollars for a 5-kilowatt system to upwards of 175,000 dollars for larger 15-kilowatt systems, significantly more than the average 27,300 dollars cost for a 10-kilowatt solar panel installation.

Factors such as the need for open space, strict permitting and zoning requirements, limited wind resource availability, and ongoing maintenance costs contribute to the difficulties of implementing wind power on a residential scale. As a result, solar power remains the more accessible and affordable clean energy option for the majority of households.

Another one of the primary concerns surrounding wind turbines is noise pollution. The spinning blades generate both aerodynamic and mechanical noise, which can be a nuisance to nearby communities. Low-frequency noise, in particular, has been linked to sleep disturbances and other potential health effects.

To address these concerns, wind turbine manufacturers and operators are continually working to reduce noise through improved turbine designs, quieter gearboxes, and blade modifications.

Additionally, regulations and guidelines often require that wind farms be sited at a sufficient distance from residential areas to minimize noise impacts and ensure that noise levels stay within acceptable limits.

WIND TURBINES vs BIRDS

Another major concern is wind energy’s impact on wildlife, especially birds. Birds can and do collide with turbine blades, often killing them and there is concern about the potential disruption as well to bird migratory pathways.

Three separate studies published in 2013 and 2014 estimated that between 140,000 and 679,000 birds die annually in the United States due to collisions with wind turbines, a range that has likely increased over the past decade as more wind farms have been constructed.

Measures such as avian radar systems, which detect birds near wind farms and temporarily shut down turbines, have been implemented in some areas to mitigate these risks. In offshore wind farms, the impact on marine life also raises concerns, with noise from pile-driving during construction affecting sensitive species like fish and marine mammals.

However, the overall impact of wind turbines on bird populations is generally considered to be lower compared to other human activities, such as habitat destruction or collisions with buildings and vehicles. In fact more birds are killed by domesticated cats than wind turbines.

Many wind farms also implement measures to minimize bird collisions, such as placing turbines in less critical habitats, using bird-friendly turbine designs, and conducting pre-construction environmental assessments to avoid key migratory routes.

One technique is to paint one turbine blade black as this is believed to enhance the visibility of the blades. The black color creates a strong visual contrast against the sky and surrounding environment, making the blades more detectable to birds, especially during low-light conditions such as dawn and dusk when bird activity is heightened.

This increased visibility helps birds recognize and avoid the spinning blades, which might otherwise blend into the background and go unnoticed. While this approach is one of several methods employed to mitigate bird fatalities, it is a simple yet relatively effective modification that contributes to reducing the risk of collisions and improving overall safety for avian wildlife around wind farms.

The Plastic Problem

There is another issue with wind turbines that does have to be dealt with head on as well - wind turbines use a lot of plastics, primarily in the construction of their blades. Plastics are not just polluting our planet and impacting wildlife but also negatively hurting human health.

The blades are often made from composite materials that include plastics, specifically epoxy or polyester resins, combined with fiberglass or carbon fiber. These composite materials are used because they are lightweight yet strong, which is crucial for the blades to be both efficient and durable.

Plastics play a key role in wind turbine blades because they help create a smooth, aerodynamic surface that captures wind efficiently. They also contribute to the blade’s ability to withstand harsh environmental conditions, such as high winds and UV radiation.

However, the use of plastics does raise environmental concerns, particularly regarding the disposal and recycling of blades at the end of their life cycle. Efforts are ongoing to improve recycling methods and develop more sustainable materials for future wind turbine blades.

To make wind turbines more sustainable and less reliant on plastics, several innovative materials and approaches are being explored.

Researchers are developing blades from bio-based composites, using natural fibers like flax or hemp combined with plant-derived resins to reduce environmental impact.

Recycled plastics are also being incorporated to lessen the demand for new materials. Additionally, efforts are focused on creating recyclable thermoplastic composites that can be melted and reformed, and experimenting with wood-based materials, which have a lower environmental footprint.

New blade designs that use less material or feature flexible components aim to further minimize impact, while hybrid materials combining metals and ceramics offer potential for enhanced performance and recyclability. These advancements seek to address the environmental challenges of traditional blade materials, improving the overall sustainability of wind energy.

As the global transition to renewable energy accelerates, wind power stands out as a pivotal force in shaping a cleaner, more sustainable future.

Despite challenges such as noise, wildlife impact, and the use of plastics, the advancements in turbine technology, energy storage, and material innovation offer promising solutions.

The impressive growth in wind energy capacity worldwide, coupled with falling costs and increasing efficiency, underscores its crucial role in meeting ambitious climate goals. With continued investment and research, the wind energy sector is poised to overcome its current hurdles and drive the transition to a low-carbon economy. As we embrace the wind’s potential, we move closer to a future where renewable energy not only powers our homes but also preserves the planet for generations to come.

Tags: explainer, sustainability

This article is free to republish on your web site, in your newsletter, magazine, newspaper, publications or blog. The imagery is cleared for use too. Please just keep the author’s name on the piece and that they are from EARTHDAY.ORG. Let us know if you re-publish so that we can try to acknowledge, tag or re post you! You can let us know via an email to davies@earthday.org or fielder@earthday.org.

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Can The World Run On Sunshine?

Allen Huang — Wed, 21 Aug 2024 15:08:30 +0000

EARTHDAY Explainers - III

Can The World Run On Sunshine?

By Allen Huang

As the shadow of climate change looms ever larger, with greenhouse gasses driving rising temperatures and wreaking havoc on our planet, the calls for renewable energy to replace fossil fuels have intensified.

Among the energy alternatives being debated, solar energy has become one of the most widely touted primarily because the raw material that powers solar is essentially ‘free’: sunshine. But is this true? Can the world run on sunshine?

What’s The Evidence ?

A new study in Nature Communications, one of the leading peer-reviewed scientific journals in the world, reveals how solar energy is poised to reshape the global energy landscape, heralding a new era of dominance in renewable electricity generation within the next two decades.

The research, led by University of Exeter scientists, shows a rapid increase in productivity and technological advancement that positions solar to substantially displace coal, oil and gas, the nonrenewable energy sources responsible for the majority of greenhouse gas emissions which are accelerating climate change. Greenhouse gasses, such as carbon dioxide and methane, trap heat in the Earth's atmosphere, causing the planet to warm and leading to devastating consequences like rising sea levels, more extreme weather events, and ecosystem disruption.

The study projects that solar energy will account for over half of global electricity generation by the year 2050, while the cost of solar is expected to decline by 60% over that same period.

“A single year of sunshine exceeds all known existing energy reserves of oil, coal, natural gas and uranium put together. The future is renewable.”

Aidan Charron, Associate Director, Global Earth Day, EARTHDAY.ORG

How does sunshine become energy?

Solar energy is converted into electricity using photovoltaic (PV) cells made from semiconductor materials like silicon. When sunlight hits these cells, it excites electrons in the semiconductor, creating free electrons and "holes" (areas where electrons are missing). This movement of electrons and the corresponding holes generate a flow of electricity in the form of direct current (DC).

These PV cells are grouped into modules, also known as panels, which can be assembled into larger modules called arrays.. The electricity generated in DC form is then converted to alternating current (AC) using an inverter, making it suitable for everyday use in homes and businesses.

One of the significant advantages of solar PV systems is their silent operation, and low maintenance, attributed to their lack of moving parts. Additionally, solar panels are designed to adapt to various environmental conditions, maintaining efficiency under different weather scenarios.

Beyond these operational benefits, it’s important to consider solar capacity — the measure of how much electricity a solar system can generate. Arrays can be scaled to fit different needs, from small residential systems on rooftops to extensive commercial solar farms. Each module functions as a small electricity generator, and when combined, they can produce a significant amount of power, solar capacity refers to the maximum electrical output a solar power installation can produce under ideal conditions.

What Determines Solar Capacity?

Solar capacity is determined by several factors, including the size of the solar array, the efficiency of the photovoltaic cells, and the amount of sunlight the system receives. Understanding solar capacity helps to evaluate how effectively a solar PV system can meet energy needs and contribute to overall energy goals.

Solar energy generation, which is the actual amount of energy created, not surprisingly followed a significant upward trajectory too. In 2023, the US generated 238,121 gigawatt-hours (a gigawatt is equal to 1 billion watts) of electricity from solar which represents an eight fold increase from the amount of electricity generated from solar just ten years earlier in 2014.

Total U.S. solar capacity is projected to grow to 673 gigawatts (GW) by 2034. With this capacity, and knowing that the average U.S. household in 2022 consumed the equivalent of 0.0108 gigawatt-hours (GWh) annually, it is estimated that solar energy could potentially power over 100 million homes in America in just ten years.

“If we put solar panels on half the world’s roof tops we could power the planet. Is it going to be easy? Nothing good is ever easy but that should not stop us. This is the world's Moon Shot , yet we can and we will achieve this.”

Kathleen Rogers, President EARTHDAY.ORG

Who Is Leading the Solar Race In The US?

In the US, California generates 68,816 gigawatt-hours and Texas generates 31,739 gigawatt-hours from solar. With the amount of solar-based electricity generated in one year, it is estimated that California could power San Francisco for 13 years, and Texas could power Austin for 2 and a half years. However, the development of solar power in these two states are facing vastly different political climates.

California has enthusiastically embraced solar energy to become the nation’s leader in solar production, perhaps due to its deeply rooted environmental policies and historical crises. Both of which have highlighted the need for renewable energy sources. The state’s journey toward solar supremacy began during the energy crises of the 1970s, which exposed the vulnerabilities of relying on fossil fuels. The state’s sunny climate, combined with its technological and economic capacity to support large-scale solar projects, further catalyzed the solar energy boom.

Leading with its ambitious Senate Bill 100 (SB 100) released in 2018, which mandated a transition to 100% zero-carbon and renewable energy by 2045, the Golden state has embraced comprehensive and structural changes to its energy system, emphasizing decarbonization through extensive investments in utility-scale solar and wind projects, alongside enhancing grid reliability and capacity. The framework is clearly designed to address environmental justice and equity, with an acute focus on solar energy.

In stark contrast, Texas appears to be retreating from its earlier welcoming stance towards renewables. Despite being the national leader in wind generation and second in solar power generation, 2023 legislative sessions have been fighting against the growth in renewable energy production. Attempting to introduce proposals that would increase the regulatory and financial burden on renewable energy projects.

These proposals, perceived by some critics as favoring the fossil fuel sector, include requiring additional state approvals for new renewable projects and imposing financial barriers that could drastically increase the cost of connecting renewable energy sources to the state grid. This legislative pushback reflects a broader political debate over the role of renewable energy in Texas’s future, suggesting a significant divergence from California's proactive renewable energy policies.

According to the 13th National Solar Jobs Census released in 2022, there are 263,883 solar energy workers across the country, working to manufacture, install, distribute, and carry out maintenance, marking a 3.5% growth in solar jobs compared to 2021.

“One recent estimate found that renewables lowered the cost of electricity to Texans by $11 billion last year, or $423 for every customer served by the state’s predominant power grid. Over the past five years, Texas has added 2,800 jobs to support wind and solar power generation at the same time that the state has lost 44,000 oil and gas extraction jobs, in part because automation has allowed producers to drill more wells while employing fewer roughnecks.”

Russell Gold, Texas Monthly, June 2023

Globally How Is Solar Doing?

In other parts of the world, solar energy is also on the rise, experiencing a rise in capacity and popularity. China has set an ambitious target of reaching 1,200 gigawatts of renewable capacity by 2030—a goal it is poised to achieve by 2025, five years ahead of schedule. This rapid expansion is exemplified by China's solar capacity, which is expected to reach nearly 1,000 gigawatts by the end of 2026.

This effort was boosted with the help of the national government through different legislations and programs providing subsidies for the PV sector since the early 2000s. While still using 63% of its energy from fossil fuels, solar energy has become 4% of the electricity grid. In 2022 alone, China installed as much solar capacity as the rest of the world combined and continued to double down on its solar initiatives in 2023.

Meanwhile, Europe is also making significant strides in the solar energy sector, driven by a sharp decrease in costs and an increasing awareness of the environmental benefits. Under the European Green Deal and the REPowerEU plan, the EU aims to dramatically increase its solar capacity, with a goal to reach nearly 600 gigawatts by 2030.

This increase represents a strategic move to reduce reliance on imported fossil fuels and enhance energy security. The EU has rolled out various initiatives such as the European Solar Rooftops Initiative and the EU Solar PV Industry Alliance to meet these ambitious targets. Additionally, solar energy jobs in the EU have surged, highlighting the sector's role in boosting the economy and contributing to the job market.

Australia too is embracing solar power, with solar PV generating around 10% of the nation's electricity by the end of 2021. Over 30% of Australian households have installed rooftop solar systems, and the capacity is growing. The Australian government has invested significantly in solar research and development, supporting projects that aim to increase solar module efficiency and reduce balance of system costs.

According to the Solar Energy Industries Association (SEIA), an industry trade association, the solar industry is poised for significant growth over the next decade, with projections showing that by 2030, one in eight American homes will use solar energy for electricity production, on track to quadruple its growth in 2020.

The Inflation Reduction Act

The Inflation Reduction Act of 2022, explicitly supports the development and manufacturing of renewable energy and made historic investments in clean energy. The Act earmarks $369 billion for climate and energy initiatives, a lot of which will go towards tax credits, both for the solar industry and for the individual homeowners, who want to install solar panels.

The Department of Energy's Loan Programs Office (LPO), has an unprecedented $400 billion to lend towards clean energy innovation. The LPO, led by the winner of the 2024 Earth Day Climate Leadership Gala award winner Jigar Shah, provides vital financing to innovative renewable projects, including solar, and is expected to encourage more private sector investment. For homeowners, the federal solar tax credit allows homeowners to deduct 30% of their system’s cost from their federal tax bill.

Will Consumers Save Money Going Solar?

Installing solar panels also has become a major cost-saving measure in dealing with increasing utility bills. After the initial investment in equipment and installation, it typically takes 5 - 15 years for solar panels to generate effectively ‘free’ electricity. With the average household consuming 10.8 megawatts-hours of electricity annually and the national average electricity rate at $0.17 per kWh as of March 2024, families spend around $1,834 per year on electricity.

Considering the 2.8% annual increase in electricity prices over the past decade, the average homeowner can expect to save approximately $46,000 over 25 years after installing solar panels.

Although solar panel warranties typically last 25 years, most systems continue to perform well for 30 years or more, leading to even greater long-term savings for homeowners. Websites such as Google’s Project Sunroof will allow homeowners to type in their address, showcase the usable sunlight per year and square footage available to construct solar panels, and calculate the potential savings compared to regular electricity bills in the long run.

All of this too comes with the added bonus that this form of energy contributes no greenhouse gasses and therefore does not contribute to climate change.

“Every time you turn on a light bulb or get in a car, you are making decisions about what kind of world you want to live in.”

Bill McKibben (2012)

That’s The Good News, Here’s The Less Sunny.

Despite its many benefits, solar power is not without its challenges.

One of the primary concerns is the variable nature of sunlight! The amount of sunlight available for conversion into electricity can be affected by the time of day, the weather, the seasons and of course location. The Global Solar Atlas, reveals how sunshine radiation and density vary significantly depending on these factors.

The sun doesn’t shine anywhere 24 hours a day, 12 months of the year, so the intermittent nature of solar energy is always going to be an issue. Which means solar power has to come with efficient and reliable energy storage solutions to ensure that on high sunshine days enough electricity is generated enough to power low sunshine days.

Researchers are working on developing more efficient lithium-ion batteries but lithium mining does have its own set of environmental issues, as well as the dangers it poses to miners. The other solution being developed are faster-charging solid-state batteries which would create better storage solutions. Solid-state batteries aim to replace the liquid electrolyte in traditional batteries with a solid material. This would make these batteries charge more quickly and potentially offer longer life.

Finally ‘net metering’, is another way of managing battery storage issues. It allows homeowners to earn credits for the excess energy that their system makes when it is very sunny and sends it back to the network electricity grid. They can either cash these credits in or use them to buy electricity back from the grid in low sunshine periods, when their solar panels are not creating the electricity they need.

Sunshine to Electricity Conversion Efficiency

The other big issue is ‘conversion efficiency’ which is the percentage of the solar energy shining on a PV device that is converted into usable electricity. In layman's terms it just means that not all the sunlight that hits solar panel arrays is turned into electricity, in fact most single sided solar panels have efficiencies of just 17-20%.

But solutions are coming. Firstly multi-junction PV cells, these panels are designed to capture more sunlight than traditional panels. Imagine stacking different types of solar panels on top of each other—each layer captures different types of sunlight. This makes these new panels up to 45% more efficient at generating electricity. Right now they are still expensive to make, so they aren’t widely available yet.

Secondly bifacial solar panels, are another innovation. These panels have cells on both the front and back. This allows them to catch sunlight that reflects off the ground or other surfaces, increasing their energy production. When paired with tracking systems that follow the sun’s path, bifacial panels can be 30-40% more efficient than regular, one-sided panels.

“For the first time in history, we can provide virtually unlimited, low-cost power to everyone. The impact on living standards worldwide will be profound. Improving the health outcomes of millions, if not billions, of people across the globe.”

Tom Cosgrove, Chief Creative and Content Officer, EARTHDAY.ORG

Solar Uses A Lot of Land

Additionally, unlike oil fields or coal mines, solar panels need to cover a lot of space to collect enough energy to power cities.

The world’s most forbidding deserts, the Sahara in Africa, the Kubuqi Desert in China, and Mojave Desert in California, have emerged as prime locations for harvesting solar power. With vast, flat expanses, rich silicon (a key material to the production of solar panels) deposits, and perpetual sunlight, deserts are ideal for solar panel installations. As this trend continues, researchers envision transforming the Sahara into a massive solar farm capable of meeting four times the world’s current energy demand.

Wildlife Can Be Impacted

While the rapid deployment of solar panels is essential for sustainable energy development, it's not without its ecological challenges. The expansion of solar farms, especially those that are ground-mounted, can lead to significant alterations in land use, potentially threatening local biodiversity.

According to a 2019 report by independent ecological consultancy firm BSG Ecology, these installations can disrupt habitats, change local flora and fauna dynamics, and may even act as ecological traps by attracting and affecting wildlife in ways that are detrimental. Large tracts of land are often cleared to accommodate solar farms, which can lead to a decrease in biodiversity.

In response to these ecological challenges, several innovative strategies are being explored. One promising approach involves integrating native vegetation and creating habitats within solar farms to support local wildlife and flora. This not only helps in preserving biodiversity but also enhances the ecological value of the area.

Additionally, some projects are adopting “agrivoltaic” systems, which combine solar energy production with agriculture, thereby supporting local communities and maintaining land productivity. Agrivoltaic systems have been widely used across the United States. Farmers use the solar panels to protect their crops, create shade and in turn save water, all while lowering their energy bills.

According to a newly published U.S. Department of Agriculture (USDA) report, solar farms occupy only 336,000 acres, or 0.04% of the entirety of all the farmland in the US. In many rural areas, such as Converse County, Wyoming, where the population density is only 3 people per square mile, local agrivoltaic projects such as the Dutchmen Project have become popular for their ability to generate general revenue and local jobs.

It Takes Energy To Make Solar Panels

While solar panels themselves do not emit greenhouse gasses the manufacturing of solar panels does require a significant amount of energy, particularly in the production of polysilicon, which involves heating giant furnaces to high temperatures.

The carbon footprint of this energy consumption varies depending on the electricity sources used by the solar panel manufacturer, for example every unit of electricity produced in China produces twice as much in carbon emissions, compared to the U.S. efforts to power photovoltaic-panel manufacturing with renewable energy sources like wind, solar, and geothermal is the most obvious solution to this.

The International Renewable Energy Agency (IRENA) predicts that there could be up to 78 million tons of solar panel waste by 2050, but this estimate assumes customers will keep their panels for the full 30-year life cycle. But with falling costs, researchers worry that consumers may choose to replace their panels much earlier, potentially leading to more waste. Current recycling infrastructure for solar panels is vastly inadequate and recycling is not financially incentivized, currently only one U.S. manufacturer (First Solar) has an active recycling initiative.

Here’s why - the cost of recycling a single solar panel is $20 - $30 which far exceeds the cost of $1 to send it to a landfill. New technology out of Australia’s School of Engineering at Macquarie University, are actively working on a solution by developing economically viable ways to delaminate solar panels more efficiently at the end of their lifespan as well as harvest the valuable materials that each panel contains, for example silver.

The Plastic Problem

Despite technological advances, the other issue that the manufacturing of solar panels is yet to solve is plastic.

Plastics are a form of petrochemical, which means it is made using fossil fuels, and it is not biodegradable in any meaningful sense, which has made it a serious environmental challenge due to the proliferation of microplastics and other harmful chemicals such as Bisphenol A and phthalates that leach out from plastics.

Currently, there are two different types of technologies used to manufacture solar panels, and both use plastic polymers, albeit in a relatively low proportion: a typical crystalline silicon PV panel includes about 10% polymer, while thin film technologies like cadmium telluride (CdTe) panels use 3-4% polymer, due to their higher glass content.

Currently, the plastic polymers in solar panel manufacturing are used primarily for encapsulating the solar cells inside the panels. This encapsulation provides a protective layer that safeguards the cells from environmental factors such as moisture, dust, and mechanical damage, ensuring the longevity and reliability of the solar panels.

In the name of cost-effectiveness, numerous leading solar panel manufacturers have shifted to incorporate more plastic in their new models which needs to be addressed. There needs to be a concerted effort by the solar industry to wean themselves off plastic and find ‘greener’ alternatives.

Hazardous Chemicals

Solar panels, particularly those using thin-film technology, also can contain hazardous materials like cadmium, selenium, gallium and indium, which pose environmental and health risks if not handled properly. Mining these materials can lead to significant soil, water and air pollution, and exposure to them can cause serious health issues.

Additionally, while silicone, the main component in most solar panels, is not toxic, the process of cutting silicon into wafers produces silica dust. This dust can be harmful if inhaled over long periods, potentially leading to silicosis, a permanent and irreversible lung disease.

Alternatives to silicon are being researched but in the meantime there should be stricter safety protocols protecting workers and better personal protective equipment (PPE), proper ventilation systems, dust extraction methods, and respiratory protection.

Global electricity generation technology expansion by technology (TWh), showing the time it has taken for key technologies to grow from 100TWh to 1,000TWh.
Source: Ember.

The Future Is Still Sunny

While there are challenges associated with solar energy, there are also viable solutions being developed every step of the way. In contrast, the fossil fuel industry lacks any effective methods for generating energy from oil, gas, or coal without producing greenhouse gasses, which are the primary driver of climate change.

As Denis Hayes, the organizer of the first Earth Day in 1970, noted solar energy has been the fastest growing energy source in the world for the last 19 years straight.

In the past three years, the use of large-scale batteries for energy storage has increased by 900 percent and a recent study by Lawrence Berkeley National Lab found that by the end of 2023, solar, wind, and battery projects accounted for 95 percent of all new electricity capacity planned for the national grid.

So solar may not be able to do it all alone, but in conjunction with other renewable energy sources, like wind, it pretty much can.

“Oil, coal and gas are finite. As long as the sun keeps rising, solar energy is infinite. That seems to present an obvious solution to our energy needs, literally staring us all in the face.”

Kathleen Rogers, President, EARTHDAY.ORG

Tags: explainer, sustainability

This article is free to republish on your web site, in your newsletter, magazine, newspaper, publications or blog. The imagery is cleared for use too. Please just keep the author’s name on the piece and that they are from EARTHDAY.ORG. Let us know if you re-publish so that we can try to acknowledge, tag or re post you! You can let us know via an email to davies@earthday.org or fielder@earthday.org.

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The Olympics vs. Climate Change

Allen Huang — Fri, 26 Jul 2024 13:00:58 +0000

EARTHDAY Explainers - II

The Olympics Vs. Climate Change

By Allen Huang

Few events match the exhilaration of the Olympic Games' opening ceremony. As the 2024 Games in Paris prepare to kick off on July 26 amid much anticipation, another discussion is gaining momentum alongside the athletic feats to come—how climate change is affecting sports? The Paris 2024 Olympics could be one of the hottest Games in human history with real concerns mounting over the implications of climate change on athletic performance and safety to come.

“The increasing temperatures and changing weather patterns are reshaping the landscape of sports, posing significant risks to athletes and events.”

Brian P. McCullough, Associate Professor of Sport Management, University of Michigan

According to the official website, the Games cover 32 sports and more than 10,000 athletes will compete in 329 medal events in a wide range of disciplines with 19 of them taking place outdoors, including track and field, sailing, equestrian, rowing and archery. It is these athletes who will be directly in the sun’s glare.

Given that the Games are being held in Paris in July and August, the hottest months of the year in the city of light, some weather forecasters are already predicting temperatures of 26.7℃ (80℉) for many of the competition days in the French capital. While this may not seem to be an extreme temperature, if you take into account the Heat Index, it becomes much more worrying.

People’s experience coping with heat is often not determined by temperature alone; scientists measure such experiences using the heat index, which often exceeds the air temperature because it takes into account both temperature and relative humidity, which affects how effectively the body can cool itself through perspiration.

As a result rising temperatures have already led to disruptions in event schedules and location changes to cooler times or venues, which could impact athlete preparation and performance. The global thermostat continues to climb, athletes across many disciplines are being forced to confront a new adversary that doesn’t discriminate based on skill level, extreme heat.

“With global temperatures continuing to rise, climate change should increasingly be viewed as an existential threat to sport.”

Lord Sebastian Coe, President of the World Athletics Association

The Evidence So Far

One of the leading pieces of available analysis on this topic came from the British Association for Sustainable Sport (BASIS), with the help of notable heat physiologists and climate scientists from University of Portsmouth and 11 Olympians. It looked at the all too real and serious threat extreme heat poses to top athletes in their report, “Rings of Fire”, the second such report.

The Rings of Fire concludes that athletes are indeed not just competing against each other, but also against the escalating threats posed by our warming planet and it is a real and serious threat.

Paris is No Stranger to A Changing Climate

Since France last hosted the Olympic Games in 1924, the average temperature in Paris has risen by 3.1°C, (5.6°F) posing significant challenges and risks to hosting the Games in Europe - the fastest warming continent on earth.

The frequency and intensity of heatwaves in the Paris region are rising dramatically, between 1947 and 2023, the region has experienced 50 heatwaves, and the situation has been particularly severe in recent years. The devastating heatwave of 2003 resulted in more than 15,000 deaths across France as whole. As recently as 2019, Paris recorded its highest ever temperature of 42.6°C (108.7℉); this heat wave killed 1,435 people across France.

The Global Trend

It is far from just Paris where the temperature is rising. According to the European Union’s Copernicus Climate Change Service (C3S), each month from June 2023 to July 2024, has been the hottest on record for its respective month since record-keeping began.

In its latest monthly bulletin, C3S indicates that 2024 may surpass 2023 as the hottest year on record. This rise in temperatures has been attributed to human-induced climate change and the natural El Niño weather phenomenon, which have both driven temperatures to unprecedented levels.

What Does Extreme Heat Do To The Human Body?

As temperatures soar to dangerous levels, the human body's regulatory mechanisms work overtime to maintain a core temperature close to 37°C (98.6°F). However, when exposed to extreme heat, these mechanisms can be overwhelmed and specific symptoms begin to manifest: heavy sweating, weakness, and dizziness, which can occur when the body struggles to regulate its internal temperature.

When humidity is high, sweat evaporates more slowly, which impedes the body's natural ability to cool down efficiently, making the perceived temperature feel hotter than the actual air temperature, thereby exacerbating the impact of heat on the body.

As temperature and humidity soar, the brain struggles to process information, leading to impaired judgment which can lead to accidents and potential injuries. The skin, responsible for cooling the body, can fail to evaporate sweat effectively in high humidity, causing heat stroke. The cardiovascular system is strained as more blood is trapped in the skin, increasing the risk of heart attacks.

Breathing hot, humid air can exacerbate respiratory conditions like chronic obstructive pulmonary disease (COPD) and asthma. Dehydration takes a toll on the kidneys, potentially leading to kidney failure or electrolyte imbalances.

Experts warn that as climate change intensifies, mitigating the health impacts of extreme heat will become increasingly critical. In extreme cases, it progresses to heat stroke, a life-threatening condition marked by confusion, rapid heartbeat, and even unconsciousness.

Heat stroke requires immediate medical intervention to prevent long-term damage or fatality and of course poses a real risk to athletes pushing their bodies to the limits in Olympic competition.

If we factor in the extreme competitive drive of athletes, which can often override their judgment when it comes to their own safety, it becomes easier to understand why Olympic and world-class athletes are increasingly weighing up a balancing act between competitive spirit and personal safety

Athletes Experience of Extreme Heat

British marathon swimmer Amber Keegan has spoken out about the impact of extreme heat creating a “nasty cocktail” of threats in her sport, an outdoor event. The physical demands of marathon swimming are already intense but the added stress of extreme heat that swimmers face can increase cramping, fatigue, and vomiting. All of which can deplete precious energy but also diminish mental clarity. Which if you are a marathon swimmer presents the possibility, of amongst other things, drowning.

Meanwhile, the account from Yusuke Suzuki, a Japanese race walker and 2019 World Champion, brings to light the long-term impacts of competing in excessive heat. Suzuki’s distressing experience, not at an Olympic Games but the Doha World Championships, where he suffered symptoms of severe dehydration and heatstroke due to extreme heat, including an elevated heart rate and gastrointestinal distress were not easy to walk away from.

Despite winning the race, the long-term effects were devastating; Suzuki struggled with overtraining syndrome, marked by chronic fatigue and muscle pain, which eventually forced him to withdraw from the Tokyo Olympics and significantly disrupted his career. His story is a chilling reminder of the prolonged recovery and lasting health issues athletes can face at the hands of extreme heat.

At the 2020 Tokyo Olympics, athletes also struggled with blistering heat and humidity, with temperatures soaring above 34℃ (93.2℉) on many days, with humidity approaching 70 percent. Live reports from Tokyo described scenes in which many athletes vomited and fainted at the finish line, needed wheelchairs to leave the field, and said they had real fears of losing their lives during the race.

One of the most infamous scenes as a result of the heatwave came from a tennis match at the Ariake Tennis Park in Tokyo, where the heat index reached a shocking 37℃ (99℉), which led Russian tennis star Daniil Medvedev to shout to the chair umpire mid-match that “I can finish the match but I can die. If I die, are you going to be responsible?” Even after winning the game, Medvedev said that he hadn't been able to breathe, felt “darkness” in his eyes and “was ready to just fall down on the court” due to the extreme heat and humidity during the match.

In order to more accurately understand the effects of hot weather on athletes, the Ring of Fire report uses a heat stress index called the Wet-Bulb Globe Temperature (WBGT) to measure the combined effects of temperature, humidity, wind speed and solar radiation on the human body.

While the original study generally concluded that the WBGT is only a threat to the human body when it reaches 35°C (95°F), a more recent study from 2022 disproves this; according to this study, as soon as the WBGT reaches 31°C (88°F), even the most young and healthy Olympic athletes are no longer able to regulate their own body temperatures, which increases the risk of heat-related illnesses such as sunburn, heat cramps, heat stroke, heat cramps, exhaustion and even heat stroke.

“Extreme temperatures, as witnessed during the Tokyo Olympics and other major events, severely impact athlete performance and safety. The body’s ability to regulate temperature is compromised, leading to risks such as heat exhaustion and heat stroke.”

Brian P. McCullough, Associate Professor of Sport Management, University of Michigan

To calculate what combination of temperature, humidity and wind would generate a specific WBGT you can use this calculator.

How Worried Are Athletes About Climate Change Impacting Them?

In 2023, a World Athletics survey revealed climate change is a growing concern among athletes, with 75% reporting negative impacts on their health and performance due to climate change—a significant increase from previous years. What is more, 90% of surveyed athletes believe World Athletics must play a crucial role in promoting a sustainable future, as extreme weather events become more frequent and severe.

To help kick start that ambition a group of athletes from across the globe, playing in different sports and governing bodies, have organized a nonprofit group called “EcoAhletes” to use the Paris Games as their platform to shine a light on the need for urgent action to tackle climate change. To achieve their goal of educating more people in sports to be wary of the climate crisis, EcoAthletes provides its members with these resources.

According to their website, these include mentoring, community outreach, and connecting athletes with climate-active brands for potential endorsement deals. In their most recent statement, they have implored the International Olympic Committee (IOC) to reconsider sponsorship deals from major gasoline vehicle manufacturer Toyota, and asked Coca-cola and Pepsi to ramp up reusable packaging for all participants of the Olympic Games. Although the 2024 Paris Olympics will be the largest sporting event ever to use reusable packaged drinks, a report by French newspaper Le Monde suggests that 40% of drinks will still be in plastic bottles.

A recent study reveals that 56 brands, primarily led by The Coca-Cola Company and PepsiCo, contribute to over 50% of the world's plastic pollution, with 400 million tons of plastic waste produced annually. Plastic production contributes annually to 5.3% of global greenhouse gasses, (GHG) which is predicted, by conservative estimates, to triple by 2050. Some reports predict plastic GHGs could contribute even more, reaching 20 - 30%, of all GHGs globally.

Can the Winter Olympics Survive?

If the issue facing the Summer Olympics is how to prevent rising temperatures from affecting the safety of athletes, the Winter Olympics faces an existential crisis. Can it find a venue, anywhere in the world, with enough snow to host it?

This is not hyperbole. A 2014 paper comprehensively analyzed historical weather data, climate models, and future projections and came to a startling conclusion: If global greenhouse gas emissions continue at their current rate, only 10 of the 21 former Winter Games hosts will be able to reliably host the Games by mid-century.

Many traditional venues for these games, such as Palisades Tahoe (1960), Grenoble (1968), and Sochi (2014), are becoming unsuitable due to decreasing snowfall by the 2050s; if carbon emissions continue at the rate they are now then only one location out the the 21 historical Winter Games venues, Sapporo (1972) in Japan, can be depended on to do so again by the 2080s. While advanced snowmaking technology can mitigate some of these issues, competitors nearly universally loathe this ‘solution’ as it cannot fully replicate real snow and of course it takes energy to produce.

It Is Not Just Olympic Athletes At Risk From Climate Change

The impact of the increasing heat index is not an Olympic only issue. Anyone watching the 2024 COPA America or the Euros cannot have failed to notice the extreme heat soccer teams were playing in, with their shirts drenched in sweat, often taking water breaks and players looking fatigued. It is also not just professional sports leagues either; across the United States, schools are struggling with maintaining outdoor activities as extreme heat hits the Western Hemisphere.

Climate Change Impacts Sports and Vice Versa

In thinking about these issues, we must recognize that sporting events do not occur in a vacuum; they also contribute greenhouse gas emissions. Previous Olympic Games, such as London 2012 and Rio 2016, produced an average of 3.5 million tons of carbon dioxide, only slightly less than the entire city of San Francisco emits in a year.

There are a variety of ways that major sporting events emit carbon dioxide, from building energy-intensive arenas, to spectator travel, to powering facilities, as well as a lack of proper recycling of plastic and food waste, all of these factors contribute to the large carbon footprint.

Should Sports Divest From Big Oil?

Is it time for a reevaluation of energy sponsorships within sports, as many of them are also major polluters. As the Rings of Fire report has pointed out, it remains an uncomfortable truth that fossil fuels are the primary drivers of global warming, responsible for nearly 80 percent of global greenhouse gas emissions, yet they continue to sponsor events that have been dramatically worsened by the rising temperatures.

“The Olympic Games should be a celebration of the very best of humanity—but the Paris Games are celebrating those companies condemning humanity to more heat, drought, and rising seas.”

Etienne Stott remarked, British Olympic gold medallist and slalom canoeist

From Saudi Aramco's involvement in FIFA, the International Cricket Council, and Formula 1, to TotalEnergies' support for the Rugby World Cup and the African Cup of Nations, the list is extensive.

The Paris Olympics is not fossil fuel sponsored but they have embraced the sponsorship of Air France, a major airline; Toyota, a major automobile manufacturer, and ArcelorMittal, one of the largest steel companies in the world as well as Coca Cola. According to new research by the New Weather Institute, the combined annual emissions from Air France, Toyota, and ArcelorMittal alone are estimated to be a staggering 33.6 million tons of carbon dioxide, which produces more pollution than eight coal plants running for an entire year.

The Olympic Pledge Needs Teeth

Organizers of the Paris 2024 Olympics have pledged that the event will be “historic for the climate,” aiming to generate no more than half the planet-warming emissions produced by recent Summer Games in London and Rio. To meet their goal, the few new structures built for these Games, the Olympic Village and the aquatic center, have been designed to generate 30 percent less carbon per square meter compared to standard projects in France.

The Paris Games will be powered primarily by the French power grid, which is one of the ‘cleanest’ in Europe due to its heavy reliance on nuclear energy. Additionally, solar panels will be installed across different venues, while the Olympic villages will not come with air conditioning units, instead relying on the building facades and water-cooled underground pipes for insulation.

Paris has implemented several measures to keep both spectators and buildings cool. Thousands of trees have been planted around the city, and light-colored surfaces and sidewalks have been installed to reflect heat. These are all notable achievements but for many they do not go far enough.

Our Future Needs More Climate Centric Action

Sports can no longer operate in a bubble, separate from the environmental crises shaping our world. While athletes are often celebrated for their physical prowess and determination, their greatest challenge yet, may be to join the fight for the future of our planet and humanity itself.

In the sweltering shadow of the five Rings, the upcoming Paris 2024 Olympics could become a pivotal moment in this ongoing battle, one where the stakes are higher than mere gold medals.

Tags: explainer, sustainability

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Is Going Electric Really Driving Us Green?

Allen Huang — Tue, 09 Jul 2024 13:20:23 +0000

Is Going Electric Really Driving Us Green?

Fuel Injection System

Fuel Tank

Powered by gas

Traction Battery Pack

Powered by electricity

Power Electronics Controller

Electric Traction Motor

Internal Combustion Module

A typical passenger vehicle emits

4.6 metric tons of CO2 per year *

Zero CO2 emissions **

By Allen Huang

On July 3, 1885, a mechanic named Karl Benz unveiled the world's first gas-powered automobile to the public in Mannheim, Germany. This groundbreaking invention would go on to revolutionize transportation, society and our entire world in ways unimaginable at the time.

Not least of all contributing to climate change, it is estimated that transportation contributes 27% of Greenhouse Gasses (GHG) emissions globally but that cars alone account for a staggering 75% of carbon monoxide emissions in the US.

However, 139 years later, as we grapple with the urgent climate crisis largely fueled by the very same internal combustion engines that once promised liberation and progress, the story of the car is evolving yet again.

Today, electric vehicles (EVs) are emerging as a crucial element in reducing greenhouse gas emissions and our dependence on fossil fuels. Governments and automakers worldwide are setting ambitious targets to transition to all-electric models, aiming to mitigate the environmental impact of transportation. It's perhaps ironic that in this very moment, as we reflect on the transformative impact of Benz's invention, we find ourselves at another pivotal juncture in automotive history.

EV vs GAS

Electric vehicles (EVs) are gaining momentum as a crucial strategy to replace gasoline cars and reduce greenhouse gas emissions. The International Energy Agency's Global EV Outlook 2024 report predicts that by 2024, EVs will constitute over one-fifth of the 17 million cars sold globally, and by 2035, they will represent half of all sales, potentially cutting oil demand by up to 10 million barrels per day, similar to current U.S. road transportation usage.

Governments and automakers worldwide, including industry giants like General Motors and Volvo, are setting ambitious goals to transition to all-electric models by as early as 2030. This shift aims to decrease reliance on oil and address climate change concerns.

According to the Department of Energy’s Alternative Fuels Data Center, AFDC, EVs contribute significantly to reducing greenhouse gas (GHG) emissions and particulate matter (PM2.5) pollution of conventional internal combustion engine vehicles (ICEVs), two of the largest factors in worsening climate and increased carbon footprint.

A 2022 research paper found that fully electric cars have a higher energy efficiency compared to ICEVs, including vehicle production, throughout the use phase, and end-of-life disposal, concluding that despite higher emissions from their battery production, the total greenhouse gas emissions over the life cycle of EVs still remain lower than those of comparable models of ICEVs, including Pickups, SUVs and Sedans. For example, while a gas-powered SUV emits 435-485 grams of greenhouse gasses per mile, a fully electric SUV only emits 199-209 grams.

The AFDC also pointed out that while electric vehicles (EVs) typically have higher initial purchase prices compared to conventional vehicles, their overall energy costs are lower, and these costs are expected to align more closely with conventional vehicles as production scales up and battery technologies improve. This phenomenon is already going into effect: EV tprices in February 2024 were 12.8% lower compared to February 2023, showing a significant year-over-year decline. In January 2024, the year-over-year decline was 11.6%, compared to January 2023, indicating that the rate of price decrease is accelerating.

However, there are other factors we should consider when determining the green merits of electric cars including the sources of the electricity needed to power them, their current dependence on lithium-ion batteries and their acceleration of tire wear, could all be points of concerns.

THE ELECTRIC POWER ISSUE

The carbon emissions of electric vehicles depend on the electricity used for charging. Regions that use low-emission or renewable energy make electric vehicles much cleaner over their lifetime compared to regions that rely on fossil fuels, especially coal.

However, according to research, the construction of clean electrical grids and the strategic replacement of coal electric plants in the United States has made the carbon emission of electricity still lower than that of gasoline cars.

This is largely due to the cleaner electricity mix and improved efficiency of electric engines over internal combustion engines. The adoption of renewable energy technologies in the power grid has contributed to lower carbon emissions in the electricity sector. This clean energy transition is integral to the environmental benefits of EVs.

Massachusetts Institute of Technology (MIT)’s website carboncounter.com — which provides interactive analysis on different types of vehicles classified by their class, powertrain, drive type and horsepower — can provide a straightforward outlook for the potential climate impact of different vehicles. To compare two similar cars based on data, the Audi Q4 e-tron (an electric SUV) and the Land Rover Evoque (a gasoline SUV), both have similar purchase, maintenance costs, and greenhouse gas emissions during production.

However, the Evoque costs $170 per month for fuel, while the e-tron costs $41 per month. Additionally, the e-tron produces 156 grams of carbon dioxide per mile, compared to the Evoque's 382 grams per mile.

Even with issues surrounding just how green the electricity is that we use to power our EVs, according to the MIT website, the vast majority of fully electric vehicles do have an emission standard below the 2030 emissions target. That’s the good news. Here’s the bad news.

LITHIUM BATTERIES

Lithium-ion batteries are used in nearly all EV as the predominant means of storing energy. Here’s how they work in electric cars: EV batteries operate on the principle of moving lithium ions and electrons through different parts of the battery to generate power. During charging, lithium ions move from the cathode to the anode across an electrolyte medium, while electrons travel via an external circuit to the anode, storing energy in the process. When the EV is driven, this process reverses: lithium ions flow back to the cathode from the anode, releasing stored energy as electricity that powers the vehicle's motor.

The production procedure of lithium-ion batteries, which are sourced from non-renewable raw materials such as lithium, cobalt, manganese, and nickel, is known for being water and carbon-intensive. Additionally, the manufacturing process generates toxic chemical byproducts, further contributing to the environmental concerns surrounding these batteries. Recycling lithium batteries remains challenging, and the EPA has reported the recurrence of fires caused by lithium batteries as more challenging to extinguish.

The other issue with lithium is that it is a finite element and mining it has led to environmental degradation. Lithium extraction, particularly in the lithium triangle (Argentina, Bolivia, and Chile), involves pumping large amounts of water from natural aquifers, which is crucial for local communities and ecosystems, and holding it in evaporation ponds, significantly reducing the volume of water returned to the environment and leading to water scarcity. The chemicals used in processing lithium from these brines, such as hydrochloric acid, can leak into the water supply or soil, contaminating local water sources and agricultural land, affecting both human populations and wildlife.

Lithium mining and processing can also disrupt local ecosystems through the creation of evaporation ponds and mining infrastructure on natural habitats, the release of toxic chemicals harmful to wildlife, the generation of dust and pollutants affecting air quality, and soil contamination impacting plant life and overall ecosystem health.

THE UNEXPECTED CONSEQUENCE OF EVs - TIRE WEAR & TEAR

The wear from vehicles poses a significant environmental problem, and this issue is exacerbated by electric vehicles (EVs). Due to the typically heavier weight and higher torque of EVs, tire wear can increase by up to 26%, according to testing results from Emissions Analytics, further contributing to the environmental impact of tire particulate matter. This in turn increases the shedding and dispersion of microplastics from the tires and these harmful plastic particles are then inhaled and ingested via water, soil and air by all of us and other animals. How does this happen?

As tires degrade, the emitted rubber, metals, and compounds accumulate along roadways, subsequently washed into waterways by rain, while finer particles remain airborne, contributing to worsening air quality. The health risks associated with the release of these toxic particulates is making global headlines and was the focus of the EARTHDAY.ORG Report - Babies Vs. Plastics.

This particulate pollution also includes a concerning chemical, known as 6PPD, which is used in tires to prevent rubber degradation. When dispersed to the atmosphere, 6PPD reacts with ozone and oxygen to form transformation products like 6PPD quinone (6PPDQ) on tire surfaces and in tire and road wear particles, which has been linked to acute mortality in aquatic life, affecting their migration and spawning processes, in a phenomenon known as “urban runoff mortality syndrome.”

6PPDQ is persistent and highly mobile in the environment, being detected in various matrices including water, soil, and air, which is concerning due to its stability and ability to travel far from its original source, potentially impacting areas not immediately adjacent to roadways or urban centers. There is growing concern about the potential health impacts of 6PPDQ on humans due to its ubiquity in urban environments, with exposure possible through inhalation of particulate matter, direct contact with contaminated water, or through the food chain, although specific health effects are still under investigation.

DO EV’s STILL WIN THE CAR WARS?

As we reflect on the 139 years since Karl Benz unveiled the first gas-powered car, it's clear that his groundbreaking invention set in motion a chain of events that have had profound impacts on our world. The story of the automobile is one of unintended consequences and unexpected twists.

Now, as we stand at the precipice of another seismic major shift in the shape of electric vehicles, it is tempting to view this transition as the end of the story – a neat resolution to the environmental challenges wrought by the internal combustion engine. However, as we've seen, the reality is far more complex. While EVs undoubtedly offer significant benefits in terms of reducing greenhouse gas emissions and dependence on fossil fuels, they also present their own set of challenges and considerations. From the environmental impact of lithium mining to the increased tire wear contributing to microplastic pollution, the road ahead is not without its obstacles.

Just as Benz could never have predicted the full scope of the impact his invention would have, we too must recognize that the story of the car is far from over. The rise of EVs, while a crucial step forward, is unlikely to be the final chapter in our quest for sustainable transportation. In July 2023, the Federal Aviation Administration (FAA) approved the testing of new flying vehicles, signaling yet another potential transformation in the way we move.

While the prospect of reducing ground traffic congestion and cutting travel times is exciting, it's essential to consider the potential environmental impact of these new aircraft, including their energy consumption, noise pollution, and the infrastructure required to support their operation. The introduction of flying vehicles into the equation adds a new layer of complexity to the already multifaceted challenge of creating a sustainable transportation future.

* https://www.epa.gov/

** https://afdc.energy.gov/

Tags: explainer, sustainability

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