Coal
Coal is a carbon-rich rock formed from plants that grew millions of years ago. Coal is a major source of electricity in the United States and the largest source of energy for electricity generation worldwide.
The Basics
Coal is a rich source of energy formed from plants that grew in swamps tens to hundreds of millions of years ago. The plants were buried deeply under younger and younger layers of dirt and rock, heated, and compressed into a carbon-rich rock.[1] Burning coal releases more carbon dioxide per unit of energy produced than any other fossil fuel.[2]
Why does coal matter?
The United States has more estimated recoverable coal reserves than any other nation except China and is a net exporter of coal. In 2017, coal provided 30% of the electricity consumed across the country, and 93% of coal consumed in the United States was used to generate electricity.[3]
How does geoscience inform decisions about coal?
Geoscientists locate coal resources, assess coal deposit volume and extent, and determine coal quality and composition for use in different industrial processes.[4] Geoscientists also study the impacts of coal production and consumption on air and water quality, and work on the remediation of land and water that have been affected by coal production.
References
2 How much carbon dioxide is produced when different fuels are burned? EIA
4 Coal Assessments Overview, USGS Energy Resources Program
Learn More
Introductory Resources
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Coal Explained, Energy Information Administration
Web overview of how coal was formed, types of coal, coal production (mining, processing, and transporting), where U.S. coal comes from, imports and exports, how much coal is left, uses of coal, prices and price outlook, and environmental impacts of coal. -
What You Need to Know: Fossil Fuels, The National Academies
An in-depth overview of the current role of each fossil fuel energy source in the United States, the benefits and disadvantages of each energy source, and opportunities and challenges for using that energy source in the future. (Discusses coal, oil, and natural gas.) -
What You Need to Know: Advanced Coal Technologies, The National Academies
An overview of new technologies to increase the efficiency of electricity generation and reduce the CO2 emissions from coal.
Resources for Educators
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Education GeoSource Network (EGS), AGI
Search for coal resources related to professional resources, curricula & instruction, teaching media, outreach programs, and other EGS collections. -
NGSS Performance Expectations, Next Generation Science Standards
4-ESS3-1, MS-ESS3-1 -
NGSS Disciplinary Core Ideas, Next Generation Science Standards
ESS3.A
Additional Resources
Explore Related Topics
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Geothermal energy is harvested by drilling into underground reservoirs of steam or water heated by the Earth. While western states like California and Nevada lead the country in geothermal energy production, emerging technologies may make it possible to extract geothermal energy throughout the United States.
Hydraulic fracturing is a technique used in one step of the extraction of energy resources. Sometimes referred to as “fracking”, its wide application over the last decade has led to debate over its risks and benefits.
Hydropower uses the energy from moving water to power machines or generate electricity. Used for over two thousand years in water mills, today hydropower is more commonly associated with electricity generation.
Global demand is rising for mineral resources of all kinds, including metals, industrial minerals, and solid fuels like coal. Mineral resources are unequally distributed around the globe, reflecting the vast differences in geology of different parts of the Earth. Geoscientists play an essential role in locating mineral resources and designing processes for their safe extraction.
Nuclear energy is produced from fission, which splits the large atoms of heavy elements like uranium into smaller atoms, releasing enormous amounts of energy. Thirty U.S. states have nuclear power plants, and nuclear energy makes up around 20% of the U.S. electricity supply.
Petroleum (“oil”) and natural gas are hydrocarbons that formed over millions of years under heat and pressure deep in the Earth. Petroleum and natural gas are the largest sources of energy in the United States.
Renewable energy comes from sources that are constantly replenished, like running water, the heat of the Earth, the Sun’s light, or wind. Renewables account for around 11% of U.S. energy consumption and 17% of electricity production.
Solar energy is energy from the Sun, which can be harnessed in several ways. Solar panels use the photovoltaic effect to generate electricity directly from sunlight. The Sun’s heat can be used directly to heat water or air, or it can be concentrated to boil water, driving steam turbines that generate electricity.
Wind energy is harnessed by wind turbines, which convert the energy of the wind into electricity. Wind energy is one of the largest sources of renewable energy. Wind farms can now be found in more than 40 states.