The large expanses of land in the United States have allowed shale gas production and solar and wind farms to develop, radically changing the U.S. power generation mix (also known as the electricity mix). Coal consumption has fallen and the country now exports oil and gas. Carbon emissions today equal 1995 levels. But the country’s love of big cars means it is still a major oil consumer.
CO2 Emissions Down
U.S. CO2 emissions in 2020 were broadly in line with 1995 levels.
Energy-related CO2See Carbon Dioxid emissions in the United States reached their peak somewhere between 2005 and 2007 at 6 billion metric tons, and then fell nearly 15% over ten years. As a result, emissions dropped back to 1995 levels, slightly above 5 billion metric tons, even as the country’s gross domestic product (GDP) almost tripled over the same period. For 2020, the level is expected to have fallen to 4.6 billion metric tons, but this is attributable to the Covid-19 pandemic and is most likely temporary1.
Coal Consumption in Decline
40% The share of gas in the U.S. power generation mix in 2020
This downward trend is due in large part to the gradual switch from coalCoal is ranked by its degree of transformation or maturity, increasing in carbon content from... to natural gas in powerIn physics, power is the amount of energy supplied by a system per unit time. In simpler terms, power can be viewed as energy output... generation2. Because it was available in large quantities – generally at low cost – and provided tens of thousands of jobs, coal, along with oil, played a key role in the development of the American economy. It is still referred to as “King Coal”, inspired by Upton Sinclair’s 1917 novel of the same name. As of 1990, coal continued to account for more than half of power generation.
Shale gasShale gas is found in deeply buried clayey sedimentary rock that is both the source rock and the reservoir for the gas... took off in the 2000s and plants burning this cleaner, cost-effective fuelFuel is any solid, liquid or gaseous substance or material that can be combined with an oxidant... replaced aging coal-fired power plants one after another. The balance was tipped in 2017, when coal’s share in the U.S. power generation mix fell to 30.1%, surpassed by natural gas at 31.7%. The shift has continued, with gas fueling nearly 40% of power generation in 2020.
Ebbs and Flows in U.S. Federal Policy
The drop in coal consumption has continued despite federal support for mines granted by former U.S. President Donald Trump. During his 2017-2021 term, President Trump pursued a policy heavily in favor of fossil fuels. His skepticism toward international efforts to combat climate change even led him to withdraw the United States from the Paris AgreementOil contract under which the oil that is produced is shared between the state and the oil company... .
After Joe Biden took office in January 2021, the United States rejoined the agreement and set the energy-transition targets of having 100% carbon-free electricityForm of energy resulting from the movement of charged particles (electrons) through a conductor... by 2035 and achieving net-zero emissions by 2050. President Biden also reinstated several environmental regulations and pledged to eliminate federal fossil fuel subsidies, particularly in the Gulf of Mexico and Alaska.
It remains to be seen whether the new policy will cut shale oilRefers to liquid hydrocarbons extracted from oil shale (see definition) by heating, pyrolysis or hydrogenation. and gas production capacity, which has allowed the United States to become an exporter of oil and gas for the first time since the 1950s. Today, the country is the world’s leading oil and gas producer, ahead of the Gulf states and Russia (see Close-Up: “United States: The World’s Leading Oil and Gas Producer”).
This federal policy will in any event enable the development of renewables to continue.
The vast expanses of land in the United States have already allowed the country to become a trailblazer in hydropower. In the early 1930s, as part of his New Deal, President Franklin D. Roosevelt launched a remarkable hydro project in the Tennessee Valley to develop the economy of the unemployment-stricken region.
Rapid technological development in solar and wind power resulted in the United States building huge solar and wind farms from the 2000s onward. While they have since been outdone by projects in China and India, installations in California and the Midwest still rank among the biggest in the world.
A wind farm such as the Alta Wind EnergyEnergy derived from the wind. Wind power involves converting the kinetic energy of moving air (wind) into electricity. Center in California has a capacity exceeding 1,500 megawatts (MW), the equivalent of a large nuclear power plant A nuclear power plant uses controlled fission of atomic nuclei to produce heat, which is recovered and utilized to produce electricity... (albeit without its regular output). The Solar Star photovoltaic power plant in Rosamond, California, has a capacity of close to 600 MW.
Production from wind farms doubled between 2012 and 2018 and solar output more than tripled between 2014 and 2018. But these two sources of power still account for only 7.5% of the U.S. power generation mix (6.3% from wind and 1.2% from solar).
Contributions from nuclear and hydropower remain stable at 20% and 7.5%, respectively.