Power plants that use coal, oil and other fossil fuels are generally not considered sustainable. The fuels are in finite supply and cause environmental and human/animal health problems when burned. Strict emissions regulations have abated the pollution problem somewhat, but heavy metals, air/water pollution, water usage, and older power plants contribute to ongoing pollution issues. Here are 15 facts and statistics that put it all into perspective.
There are about 7,658 power plants in the U.S.: These include plants with operational generators that can produce at least 1 megawatt of power. There may be multiple generators in a single plant that use one or more types of fuel. Coal plants are a leading source of carbon dioxide emissions, accounting for 1.7 billion tons in 2011.
Fossil fuels generate the most electricity: Coal, petroleum, and natural gas are used to generate about 65 percent of the electricity in the United States, according to the U.S. Energy Information Administration (EIA). Of the major energy sources, natural gas represented a 33.8 percent share in 2016, and coal represented 30.4 percent. By comparison, nuclear power generation had a 19.7 percent share and renewables had a total of 14.9 percent.
Coal power plants release particulate matter: Soot contains particles anywhere from 2.5 to 10 micrometers in diameter. These have irregular surfaces that allow sulfur dioxide and nitrogen oxides to bind to them. If it doesn’t have a control system, a typical plant can emit as much as 500 tons of particles into the air each year. The particles can cause health problems such as asthma, chronic bronchitis, and even premature death.
Mercury is released during coal combustion: In general, power plants emit 50 percent of the mercury released into the air, and 75 percent of the acid gases released. That accounts for 40 to 52 tons of it per year. Mercury vapor is highly toxic, and can easily enter water and be converted by bacteria into a neurotoxin known as methyl mercury, which can cause seizures, cerebral palsy, and even death. The Mercury and Air Toxic Standards that went into effect in 2011 aim to limit how much pollution coal-fired power plants can emit; after some delay, a final finding was released in 2016 supporting the benefits of reducing mercury and other toxins.
Power plants have reduced mercury emissions by 10 percent: Since 1990, plants have worked to meet emissions standards. They went from 59 emissions tons per year then to 53 in 2005. By comparison, municipal waste combustors reduced their emissions by 96 percent and medical waste incinerators by 98 percent, to just one emissions ton per year, according to the U.S. Environmental Protection Agency (EPA). In 2016, coal plants released 1,241 million metric tons of CO2, or a 68 percent share of the total of 1,821 million metric tons, per EIA statistics.
An uncontrolled coal plant releases many harmful pollutants: These include about 114 pounds of lead, traces of uranium, and 720 tons of carbon monoxide. Also, 220 tons of hydrocarbons are released, which trigger reactions that form ozone at low altitudes. A plant also releases 225 pounds of arsenic in a year, a carcinogenic compound that affects drinking water. If there are 50 parts per billion of arsenic or more in a water sample, one in 100 people may get cancer by drinking it.
Power plants discharge polluted water: Many power plants are placed along bodies of water, where they can draw it in for cooling. Billions of gallons may be used daily. The water is then delivered back to the river or sea, creating warm plumes, which can starve aquatic life of oxygen in summer and trap species in ice-free areas during the winter. Discharge waters may also contain chlorine and heavy metals.
Power plant cooling intakes harm aquatic life: Cooling water intakes draw fluid in at a high rate. Young fish, eggs, and larvae are unable to escape the currents, and often die when being forced through a cooling system. Suction and intake screens can also trap adult fish.
Power plants emit more pollution than cars: According to Environment America, power plants emitted three times as much pollution as cars in 2007. They released about 2.56 billion tons of pollutants that contribute to global warming. Most of these were from coal plants built prior to 1980.
Older power plants emit more pollution: In 2007, two-thirds of electricity generated from plants using fossil fuels came from facilities built before 1980. About 70 percent of pollution from power plants came from older ones, including those in New York, Wisconsin, Indiana, North Carolina, and Iowa.
Coal and hydroelectric are the most deadly forms of power: The deadliest type of power plant is coal, which accounts for 2.8 to 32.7 deaths per 10 kilowatt-hours, based on analyses cited in Business Insider. Hydroelectric caused 1.0 to 1.6 deaths per 10 kilowatt-hours, and nuclear power was considered the least deadly. Dams were cited as among the riskiest power generating facilities in the world.
Nuclear power has caused the fewest deaths: Global Climate Change estimated that nuclear power, from 1971 to 2009, prevented more than 1.8 million deaths around the world. Experts say it prevented more deaths than it caused, and prevented more carbon dioxide equivalent emissions than it released.
Pollution control can make power plants safer: Flue gas combustion modification can change oxygen content or temperature of combustion to reduce the amount of partially oxidized nitrogen compounds. Electrostatic precipitators can trap solid or liquid particles from gas streams using electric charges, while flue gas deacidifiers can remove nitric and sulfuric acids via solid basic oxide reactions or wet scrubbers.
Air pollution has dropped, as the economy has grown, since the Clean Air Act: Since the Act was introduced in 1970, common pollutants such as carbon monoxide, ozone, sulfur dioxide, and others dropped an average of 70 percent. Since the same year, the EPA said gross domestic product grew by 246 percent.
Reduced power plant emissions have cut acid rain: National restrictions on air pollution has cut sulfur dioxide emissions, which has reduced the amount of acid rain reported and introduced into lakes and streams. Sulfate deposits, according to the EPA, dropped by over 55 percent in the Eastern U.S. between two observation periods – from 1989 to 1991 and 2009 to 2011.