Electricity's Air Pollution: Is It A Real Concern?

The generation and delivery of electricity can have a significant impact on the environment, including air pollution. Power plants that burn fossil fuels, such as coal, gas, oil, and biomass, release harmful pollutants into the atmosphere, including carbon dioxide, nitrogen oxide, and mercury, contributing to climate change and threatening public health. Nuclear power plants, while not producing greenhouse gases, create radioactive waste that can remain toxic for thousands of years, causing cancer and genetic mutations. Even renewable energy sources, such as wind farms, can endanger flying animals. The transition to clean, renewable, and non-combustion sources of electricity is critical for reducing air pollution and its associated health risks.

Fossil fuels and electricity generation

Fossil fuels, such as coal, oil, and natural gas, are the largest source of global carbon dioxide (CO2) emissions. They are formed from the remains of long-dead plants and animals, which, over millions of years, transform into oil, natural gas, and coal through heat and pressure. Fossil fuels are burned to generate electricity, a process known as thermal generation. While burning coal or oil, giant boilers filled with water are heated, converting the water into steam, which creates pressure that rotates a turbine to produce electricity.

The burning of fossil fuels has been a common practice for electricity generation, powering the Industrial Revolution and improving the quality of life worldwide. In 2016, Canada derived about 9.3% of its electricity from coal, 9.6% from natural gas, and 0.5% from oil and diesel. Similarly, in 2003, 25% of electricity in Ontario, Canada, was generated from coal. Currently, coal is the largest source of electricity globally, with gas being the second-largest source. Over 60% of the world relies on coal, oil, and natural gas for electricity production.

However, burning fossil fuels has detrimental consequences for the environment and human health. It contributes to climate change by releasing carbon dioxide and other greenhouse gases, with electricity generation accounting for about 25% of global emissions. For instance, in 2016, while coal constituted only 9.3% of Canada's electricity generation, it was responsible for 67.8% of the country's electricity generation greenhouse gas emissions. The combustion of fossil fuels also emits harmful pollutants, including nitrogen oxides and sulfur dioxide, which can lead to acid rain, harming soils, forests, lakes, and rivers. These emissions have significant health impacts, especially on individuals residing near power plants and downwind, potentially causing cancer and other health issues.

To mitigate the adverse effects of burning fossil fuels, various measures have been implemented. The United States, for instance, has enacted laws such as the Clean Air Act to regulate air pollutant emissions from power plants. The Act has successfully reduced emissions of major air pollutants, and power plants employ various methods to meet emission standards, such as burning low-sulfur-content coal, co-firing wood chips with coal, and using particulate emission control devices. Nevertheless, transitioning to clean, renewable, and non-combustion sources of electricity, such as solar, wind, geothermal, and tidal power, is critical for lung health and combating climate change.

Electricity transmission and distribution

The transmission and distribution of electricity are two distinct but complementary operations. Electricity transmission involves carrying electricity, generated at power plants, over long distances at high voltage. The transmission network can be thought of as the "motorways" of the electricity network, with high-voltage power lines carried by large pylons and overhead lines.

On the other hand, electricity distribution is about delivering electricity to where it is needed, at lower and more usable voltages. Distribution networks are like the "local roads" that connect the transmission network to communities. In Britain, for example, the distribution network operator, Western Power Distribution, connects the transmission network to homes and businesses, ensuring electricity reaches the end consumer.

The transmission and distribution systems work together to ensure electricity gets to where it is needed safely and efficiently. Smart devices on transmission and distribution lines help manage voltage levels and identify problems, allowing for remote corrections in the electrical distribution system.

The electricity sector is facing challenges due to aging infrastructure. Older transmission and distribution lines need replacement or upgrades to maintain reliability and accommodate new renewable energy sources, often located far from demand centres. Additionally, there are regulatory and financial complexities surrounding the construction of new transmission lines, particularly when the benefits are spread across multiple states or regions.

To mitigate the environmental impact of electricity generation and transmission, various countries have laws and standards in place. For example, the United States has the Clean Air Act, administered by the Environmental Protection Agency (EPA), which regulates air pollutant emissions from power plants and has helped reduce emissions of major air pollutants.

Pollution control and reduction

Power plants that burn fossil fuels or other fuels for electricity emit harmful air pollutants that are detrimental to lung health. These include carbon dioxide, sulfur dioxide, nitrogen dioxide, carbon monoxide, and mercury, as well as hazardous pollutants that can cause cancer. The burning of solid fuels, such as coal, biomass, and municipal solid waste, results in ash—a solid residue that contains hazardous materials captured by pollution control devices.

To address this issue, the United States has implemented laws like the Clean Air Act, which regulates air pollutant emissions from power plants. The US Environmental Protection Agency (EPA) enforces this Act and sets emission standards for power plants through programs like the Acid Rain Program. These standards include burning low-sulfur-content coal, co-firing wood chips with coal, and pretreating and processing coal to reduce undesirable compounds in combustion gases. Power plants also utilize various emission control devices, such as baghouses, electrostatic precipitators, and wet scrubbers, to treat combustion gases and remove pollutants.

Additionally, transitioning to clean and renewable energy sources, such as solar, wind, geothermal, and tidal power, is crucial for reducing air pollution and mitigating climate change. These "zero-emission" sources of electricity can significantly improve lung health and reduce premature deaths caused by air pollution.

At the individual level, people can contribute to pollution control and reduction by:

• Using electric or hand-powered lawn equipment instead of gas-powered engines, as the latter often lack pollution control devices.
• Choosing efficient appliances and heating systems, as well as turning off electrical devices when not in use to reduce energy consumption.
• Driving less, carpooling, biking, using public transportation, or opting for electric vehicles to reduce vehicle exhaust emissions, a major source of air pollution.
• Planting and caring for trees, as they filter pollutants, absorb carbon dioxide, and release oxygen into the atmosphere.

Nuclear energy and radioactive waste

Nuclear power plants do not produce greenhouse gases, PM, SO2, or NOx, but they do produce two general types of radioactive waste: low-level waste and high-level waste. Low-level waste is stored at nuclear power plants until the radioactivity in the waste decays to a level safe for disposal as ordinary trash, or it is sent to a low-level radioactive waste disposal site. Low-level waste includes contaminated protective shoe covers, clothing, wiping rags, mops, filters, reactor water treatment residues, equipment, and tools.

High-level waste, which includes highly radioactive spent nuclear fuel assemblies, must be stored in specially designed storage containers and facilities. Used nuclear fuel is kept in either wet or dry storage facilities, where it cools down before being recycled or disposed of. The recycling and disposal of high-level waste are made easier by allowing the fuel to cool and for radioactivity to diminish.

Nuclear fuel is very energy-dense, so only a small amount is required to produce large amounts of electricity. As a result, a small amount of waste is produced. On average, the waste from a reactor supplying a person's electricity needs for a year would be about the size of a brick, with only 5 grams of high-level waste. In comparison, a 1,000-megawatt coal-fired power plant produces approximately 300,000 tonnes of ash and more than 6 million tonnes of carbon dioxide each year.

There are misconceptions about nuclear waste, such as the idea that because certain parts of nuclear waste remain radioactive for billions of years, it poses a sustained threat for that duration. However, nuclear waste only remains weakly radioactive for a few hundred thousand years, and the radioactivity from the main component of the waste will have decayed to safe levels within a few hundred years. The quantity of radioactive materials that would enter the environment in the event of a leak would be very small and would make no difference to the natural environment or future humans.

The transport of nuclear waste is also highly regulated and safe. About 15 million packages of radioactive material are transported each year, and there has been no instance of radioactive release causing harm to people, property, or the environment. The packaging of nuclear waste during transport is designed to ensure shielding from radiation and containment of waste, even in extreme accident conditions.

Climate change and ecosystem impacts

Climate change is having a profound impact on the energy sector, and electricity generation plays a significant role in this dynamic. The burning of fossil fuels to generate electricity releases greenhouse gases, primarily carbon dioxide, leading to a warmer planet. This warming has already reached 1.2°C since the 19th century, and its consequences include increased droughts, rising sea levels, and a growing number of species extinctions.

The energy sector is the largest emitter of greenhouse gases, and as the demand for cooling increases, more electricity is required, creating a cycle of increased emissions. This trend will likely lead to more air pollutants and greenhouse gases being released, further exacerbating climate change. Additionally, the energy system is vulnerable to the impacts of climate change, such as rising temperatures, heatwaves, severe droughts, and intense rainfall. These impacts can affect energy production and infrastructure, as seen with the closure of nuclear plants due to rising water and air temperatures to prevent overheating.

To address these challenges, a transition to more sustainable electricity generation methods is necessary. Wind, water, and solar energy are examples of renewable energy sources that do not release polluting gases into the atmosphere. These sources are not only environmentally friendly but also provide an unlimited energy supply. Electric cars, for instance, have gained popularity since the 1990s due to their reduced carbon dioxide emissions and absence of harmful pollutants.

Furthermore, individuals and organizations can play a role in reducing climate change's impact on the energy sector. Energy conservation through the use of ENERGY STAR-certified products and access to clean technologies, such as wind and solar power, can help mitigate emissions. Modernizing infrastructure and ensuring energy affordability are also crucial steps in this process. By taking these actions, we can increase resilience, improve safety, and protect public health while addressing the climate crisis.

In summary, the climate crisis and electricity generation are intricately linked, with the former exacerbating the impacts on the energy sector and the latter contributing to greenhouse gas emissions. However, by adopting more sustainable electricity generation methods and implementing conservation measures, we can mitigate these effects and work towards a more environmentally friendly future.

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