Electricity Generation: Polluting Our Planet?

Generating electricity can cause pollution, and nearly all parts of the electricity system can affect the environment. The size of these impacts depends on how and where the electricity is generated and delivered. In the United States, power plants that burn fossil fuels or materials made from fossil fuels were the source of about 31% of total energy-related CO2 emissions in 2022. These power plants also emit a long list of harmful pollutants and contribute to the formation of others, such as hazardous heavy metals and particulate matter (PM), which have been linked to asthma, chronic bronchitis, emphysema, and lung cancer. However, new and existing power plants can reduce environmental impacts by increasing generation efficiency, installing pollution controls, and leveraging cleaner energy supply resources, such as wind and solar power, which emit little to no greenhouse gases or pollutants into the air.

Burning fossil fuels

The release of these substances has far-reaching consequences for the environment and human health. Carbon dioxide, a greenhouse gas, accumulates in the atmosphere, intensifying the greenhouse effect and increasing the Earth's average air temperatures. This, in turn, contributes to climate change, altering ecosystems and causing environmental damage. The combustion of fossil fuels also emits toxic air pollutants, which have been linked to respiratory and cardiovascular diseases, as well as cancer. These pollutants disproportionately affect vulnerable groups, including children, pregnant women, the elderly, and those in developing countries.

Air pollution is a significant issue associated with burning fossil fuels. Sulfur dioxide, carbon monoxide, nitrogen oxides, and particulate matter are released during combustion, contributing to respiratory and cardiovascular diseases. Water pollution is another adverse effect, as sulfur dioxide can dissolve in water, creating sulfuric acid, which leads to acid rain. This acid rain can damage freshwater sources and harm local crops and soil acidity levels. Additionally, the burning of fossil fuels requires large amounts of freshwater for cooling, which can cause stress for local species.

The impact of burning fossil fuels extends beyond the immediate environmental and health concerns. It contributes to global inequality and environmental injustice, as vulnerable communities bear the brunt of the negative consequences. Furthermore, the combustion of fossil fuels has been linked to epigenetic changes in newborns, potentially altering genes involved in disease pathways.

Transitioning to clean energy sources, such as renewable energy (hydroelectricity, wind power, and solar energy) or nuclear power, is essential to mitigate the effects of burning fossil fuels. These alternatives offer a significant reduction in emissions, helping to slow climate change and improve air quality, which is crucial for protecting public health, especially for vulnerable populations.

Renewable energy sources

The generation of electricity can cause pollution, and this is influenced by the type of energy source used. Renewable energy sources are generally considered to be much cleaner and to produce less pollution than non-renewable sources. The most common renewable energy sources include wind, solar, and geothermal power, with wind and solar being the safest and most common.

Solar energy systems do not emit pollution or greenhouse gases, and solar panels have few environmental impacts beyond the manufacturing process. However, solar panels are constructed using semi-toxic materials that are difficult to recycle, and solar thermal systems often employ toxic fluids to transmit heat, which can harm the environment. Additionally, huge solar facilities can harm the environment by clearing land for development and installation, which may negatively impact native plants and animals.

Wind power is one of the cheapest energy sources in countries like the US and is expected to become the largest renewable energy source for electricity in the country. While wind energy has minimal pollution, the construction of wind facilities and the disposal of retired equipment, such as wind turbines, can have detrimental effects on the environment.

Hydropower is the largest renewable energy source for electricity in the US, and it produces little to no emissions that cause air pollution. However, large hydroelectric dams create a difficult trade-off when considering their impact on wildlife and climate change.

Geothermal energy relies on the heat produced within the Earth to generate electricity. It produces only one-sixth of the carbon dioxide that a natural gas power plant produces and minimal NO2 or SO2 pollution.

Biomass, which involves burning solid waste, wood, and leftover plant life, can create significant air pollution. However, pyrolysis, where biomass is heated in an anaerobic environment, is a potential alternative that produces fewer air pollutants.

Power plant emissions

Power plants emit a variety of harmful pollutants, including carbon dioxide (CO2), sulphur dioxide (SO2), nitrogen oxides (NOx), particulate matter (PM), and heavy metals such as mercury. These emissions contribute to air, water, and soil pollution, affecting human health and the environment.

In the United States, power plants that burned fossil fuels or materials made from fossil fuels, such as coal, natural gas, or petroleum, were responsible for about 60% of the total annual utility-scale electricity net generation in 2023. However, these power plants accounted for a staggering 99% of the associated CO2 emissions. Additionally, some types of geothermal power plants and fuels and gases derived from fossil fuels contributed to the remaining 1% of CO2 emissions.

The combustion of fossil fuels and biomass in power plants results in the emission of greenhouse gases and other air pollutants. These emissions contribute to global warming, climate change, and air quality issues. To address these concerns, the U.S. Environmental Protection Agency (EPA) has implemented regulations, such as the Clean Air Act, to reduce emissions from power plants. The Clean Air Act sets emissions standards and guidelines for power plants, aiming to minimize their environmental impact.

To comply with these regulations, power plants employ various strategies. Some power plants burn low-sulfur-content coal or cofire wood chips with coal to reduce SO2 emissions. Pretreating and processing coal can also reduce undesirable compounds in combustion gases. Different particulate emission control devices, such as baghouses and electrostatic precipitators, are used to treat combustion gases before they are released into the atmosphere.

In addition to centralized power plants, there is a growing trend towards distributed generation, where electricity is generated closer to where it will be used. This includes technologies such as onsite solar panels and combined heat and power (CHP) systems, which produce electricity and heat simultaneously from the same fuel source. Distributed generation helps reduce electricity losses during transmission and can provide cleaner, more reliable power to customers.

Environmental impact

Electricity generation has a significant impact on the environment, and nearly all parts of the electricity system can affect the natural world. The extent of these effects depends on how and where the electricity is generated and delivered. The burning of fossil fuels, such as coal, oil, and gas, for electricity generation causes a large proportion of greenhouse gas emissions, including carbon dioxide and nitrous oxide, which contribute to global warming. Fossil fuel combustion also produces air pollutants that are harmful to human health, such as fine particulate matter (PM) and heavy metals like mercury. These pollutants can lead to respiratory issues, including asthma, chronic bronchitis, and potentially emphysema and lung cancer.

The environmental impacts of electricity generation extend beyond air pollution. The generation process can result in water pollution, including thermal pollution, when water bodies are heated to temperatures higher than their natural state. Additionally, electricity generation can lead to the generation of solid waste, which may include hazardous materials. For instance, coal-fired power plants produce ash, a solid residue containing hazardous substances captured by pollution control devices. The storage of this ash sludge in retention ponds poses risks to groundwater, and the rupture of these ponds has caused extensive pollution downstream.

Furthermore, the electricity generation process requires the use of water resources for steam production, cooling, and other functions, which can impact ecosystems and affect plants, animals, and ecosystems. Land use for fuel production, power generation, and transmission infrastructure also contributes to the environmental footprint of electricity generation.

However, it is important to recognize that not all electricity generation methods have the same environmental impact. Renewable energy sources, such as wind, solar, and water, are cleaner alternatives that emit little to no greenhouse gases or pollutants into the air. These sources are gaining traction, with about 29% of electricity currently being generated from renewable sources. Additionally, distributed generation, such as onsite solar panels, can help deliver clean and reliable power while reducing electricity losses during transmission.

To mitigate the environmental impacts of electricity generation, power plants can increase generation efficiency, install pollution controls, and transition to cleaner energy supply resources. End-users can also play a role by adopting energy-efficient technologies and practices, reducing the overall need for electricity generation.

Clean energy

The generation of electricity can cause pollution, particularly when burning fossil fuels. Power plants that burn fossil fuels emit a long list of harmful pollutants and contribute to the formation of other pollutants, which can have a detrimental impact on human health and the environment.

However, the transition to clean energy is gaining momentum, with a growing number of states adopting clean energy plans and climate goals. This shift towards renewable and sustainable energy sources is driven by the recognition that traditional power plants contribute significantly to air pollution and global warming. Clean energy refers to energy sources that have minimal impact on the environment, such as solar, wind, water, geothermal, bioenergy, and nuclear power.

The U.S. Department of Energy is actively working to advance clean energy technologies and reduce their costs to make them more accessible. For example, the Energy Department is investing in geothermal energy, hydropower, marine energy, and the sustainable transformation of biomass energy. Additionally, the Advanced Research Projects Agency-Energy (ARPA-E) funds early-stage energy technologies, while the Office of Energy Efficiency & Renewable Energy (EERE) aims to make renewable energy cost-competitive with traditional sources.

The clean energy industry in the U.S. is already generating hundreds of billions in economic activity and is expected to continue growing rapidly. This growth is driven by the increasing adoption of renewable energy sources, such as wind and solar power, which are becoming more affordable and accessible. For instance, distributed generation technologies, such as onsite solar panels, allow electricity to be generated and used on-site, reducing electricity losses during transmission.

Furthermore, organizations like the Clean Energy Group (CEG) are working to advance equitable clean energy policies and support local energy resilience in underserved communities. CEG assists states and municipalities in developing resilient power solutions for community centers, fire stations, and affordable housing, ensuring that the benefits of clean energy are accessible to all.

Frequently asked questions