Environmental impact of electricity generation
Electric power systems consist of generation plants of different energy sources, transmission networks, and distribution lines.
Each of these components can have environmental impacts at multiple stages of their development and use including in their construction, during the generation of electricity, and in their decommissioning and disposal.
[2][3][4] This page is organized by energy source and includes impacts such as water usage, emissions, local pollution, and wildlife displacement.
The goal of such assessments is to cover the full life of the source, from material and fuel mining through construction to operation and waste management.
In 2014, the Intergovernmental Panel on Climate Change harmonized the carbon dioxide equivalent (CO2e) findings of the major electricity generating sources in use worldwide.
[7] All thermal power plants (coal, natural gas, nuclear, geothermal, and biomass) use water as a cooling fluid to drive the thermodynamic cycles that allow electricity to be extracted from heat energy.
Steam-cycle plants (nuclear, coal, NG, solar thermal) require a great deal of water for cooling, to remove the heat at the steam condensers.
Coal- and gas-fired boilers can produce high steam temperatures and so are more efficient, and require less cooling water relative to output.
[15] This results in an increase in the Earth's levels of atmospheric carbon dioxide, which enhances the greenhouse effect and contributes to global warming.
In the past, plant owners addressed this problem by building very tall flue-gas stacks, so that the pollutants would be diluted in the atmosphere.
In 2022 the IEA said that greenhouse gas emissions from gas-fired power plants had increased by nearly 3% the previous year and that more efforts were needed to reduce them.
It found that under typical inflation conditions, the lifecycle cost of natural gas and reversible, air-source heat pumps are nearly identical, which in part explains why heat pump sales have surpassed gas furnace sales in the U.S. for the first time during a period of high inflation.
The study[26] concludes: "The real internal rate of return for such prosumer technologies is 20x greater than a long-term certificate of deposit, which demonstrates the additional value PV and HP technologies offer prosumers over comparably secure investment vehicles while making substantive reductions in carbon emissions."
Nuclear power plants do not burn fossil fuels and so do not directly emit carbon dioxide.
[42] There is a catastrophic risk potential if containment fails,[43] which in nuclear reactors can be brought about by overheated fuels melting and releasing large quantities of fission products into the environment.
Unlike coal and natural gas, they can generate electricity and fuels without releasing significant quantities of CO2 and other greenhouse gases that contribute to climate change, however the greenhouse gas savings from a number of biofuels have been found to be much less than originally anticipated, as discussed in the article Indirect land use change impacts of biofuels.
[48] However, methods and opportunities exist to deploy these renewable technologies efficiently and unobtrusively: fixed solar collectors can double as noise barriers along highways, and extensive roadway, parking lot, and roof-top area is currently available; amorphous photovoltaic cells can also be used to tint windows and produce energy.
[49] The major advantage of conventional hydroelectric dams with reservoirs is their ability to store potential power for later electrical production.
Other advantages include longer life than fuel-fired generation, low operating costs, and the provision of facilities for water sports.
These may include: dislocation of people living where the reservoirs are planned, release of significant amounts of carbon dioxide at construction and flooding of the reservoir, disruption of aquatic ecosystems and bird life, adverse impacts on the river environment, and in rare cases catastrophic failure of the dam wall.
Small hydro and run-of-the-river are two low impact alternatives to hydroelectric reservoirs, although they may produce intermittent power due to a lack of stored water.
[69] Some wind farms are opposed for potentially spoiling protected scenic areas, archaeological landscapes and heritage sites.
[70][71][72] A report by the Mountaineering Council of Scotland concluded that wind farms harmed tourism in areas known for natural landscapes and panoramic views.
Enhanced geothermal systems (EGS) fracture underground rock to produce more steam; such projects can cause earthquakes.
[92] However, risks associated with "hydrofracturing induced seismicity are low compared to that of natural earthquakes, and can be reduced by careful management and monitoring" and "should not be regarded as an impediment to further development of the Hot Rock geothermal energy resource".
[97] Solar power carries an upfront cost to the environment via production with a carbon payback time of several years as of 2022[update],[97] but offers clean energy for the remainder of their 30-year lifetime.
[94] According to a 2021 study, obtaining 25% to 80% of electricity from solar farms in their own territory by 2050 would require the panels to cover land ranging from 0.5% to 2.8% of the European Union, 0.3% to 1.4% in India, and 1.2% to 5.2% in Japan and South Korea.
[107] However some countries, such as South Korea and Japan, use land for agriculture under PV,[108][109] or floating solar,[110] together with other low-carbon power sources.
The study cautions that supply needs to increase rapidly to match demand from large-scale deployment of solar and required grid upgrades.
[118][119][120] Although maintenance cost is already low compared to other energy sources,[121] some academics have called for solar power systems to be designed to be more repairable.
