The United States is home to many different natural resources, including fossil fuel
, renewable energy , and nonenergy mineral resources (such as gold, copper, and iron). Since the 19th century, natural resource extraction has been a major industry in the U.S., with fluctuations over time. Explore production data.
Fossil fuels are our main source of electricity, and the primary fuel for powering motor vehicles and heating homes. Fossil fuel resources comprised approximately 80% of total U.S. energy consumption in 2015 (PDF) (nuclear energy comprised 9%, and renewable energy 11%).
Besides creating energy, these natural resources are also used to make many products. For example, manufacturers use oil to make asphalt and coal to make steel. Through natural processes over hundreds of millions of years, plant and animal matter becomes energy resources in the form of oil, gas, and coal. While fossil fuels are abundant, they are not renewable.
Oil forms in underground reservoirs on land and under the ocean. Crude oil occurs naturally, while petroleum products (for example, jet fuel, diesel fuel, and heating oil) come from refining and otherwise processing crude oil and other liquids. Petroleum is a broad term that can mean both crude oil and petroleum products
Gas, also called natural gas, forms underground on land and offshore in beds under the ocean. There are two types of natural gas: dry and wet. Dry natural gas is mostly methane. Wet natural gas contains a small amount of methane, as well as other liquid hydrocarbons — such as ethane, propane, and butane — and nonhydrocarbon gases. Wet natural gas is the source of natural gas liquids. Once wet natural gas is extracted from the ground, natural gas liquids are separated from the gas stream close to the well or at a gas processing plant. This leaves both dry gas and natural gas liquids such as ethane, propane, and butane.
The U.S. produces more gas than any other country in the world. In 2015, five states produced 65% of the total dry natural gas: Texas, Pennsylvania, Louisiana, Wyoming, and Oklahoma.
In conventional extraction, companies extract oil and gas by drilling a vertical well. At first, oil and gas rise to the surface of the well fueled by underground pressure. Once the pressure gives out, operators can inject gases or water from the initial drilling back into the formation to increase pressure and push additional resources to the surface, or install pumps to help provide artificial lift for oil production. Finally, operators can inject steam, gases, or other chemicals into the formation to change the oil’s composition so that it can more easily rise through the well.
Extraction methods for oil and gas changed significantly starting in the early 2000s, with the new applications of horizontal drilling and hydraulic fracturing, commonly known as fracking. Horizontal drilling creates lateral wells for oil and gas to flow through. Hydraulic fracturing pumps water, sand, and chemicals into the earth to fracture the shale rock so that natural gas and oil can flow through the cracks into the well and then to the surface. These methods made extracting oil and gas trapped in almost impermeable shale rock formations deep below the surface of the earth profitable for extractive industries.
In the past decade, these changing extraction methods and rising natural gas prices have made shale oil and gas increasingly attractive to extractive industries. Major oil and gas shale rock formations include the Permian, Haynesville, and Eagle Ford Regions mostly in Texas; the Marcellus Region in West Virginia, Pennsylvania, and New York; the Niobrara Region in Wyoming and Colorado; and the Bakken Region in North Dakota and Montana.
In addition to these shale formations, the Green River Formation, which is located at the intersection of Colorado, Utah, and Wyoming, is estimated to hold 1.44 trillion barrels of oil (PDF). In shale gas, two Appalachian plays
To see where oil and gas resources exist and where exploration is taking place, visit the following:
- Different types of oil and gas plays
- Current and prospective shale plays (PDF)
- Undiscovered, technically recoverable gas resources (PDF)
- Offshore exploration and development plans
Coal forms in the ground in coal seams or beds. Miners extract coal through surface and subsurface mining. In surface mining, the coal is close to the surface. Miners remove the “overburden,” or the soil and rock covering the coal, before mining it. In subsurface mining, the coal is farther down in the earth. Through passages that go into the earth, miners remove the coal from underground rooms or long coal seams. In 2014, the U.S. was the world’s second largest coal producer after China.
Coal is concentrated in three regions: the Appalachian Region, the Interior Region, and the Western Region. In recent years, the Western Region — most of which is the Powder River Basin in Wyoming — produced more than half of U.S. coal. From 2014 to 2015, proved coal reserves decreased by 5.3% (PDF).
See where the U.S. gets its coal, or learn about coal reserves and their locations.
What are reserves?
There are three common types of reserves, or the amount of a particular natural resource available for extraction:
- Proved reserves are the estimated volumes of a natural resource that geological and engineering data demonstrate with reasonable certainty to be recoverable in future years from known reservoirs under existing economic and operating conditions
- Technically recoverable resources include natural resources that can be produced based on current technology, industry practices, and geological knowledge
- Economically recoverable resources are the portion of technically recoverable natural resources that can be profitably produced
Renewable energy resources include geothermal, solar, wind, biomass, and hydrokinetic energy, all of which constitute growing sources of environmentally sustainable energy to meet the country’s electricity needs. Renewable energy sources comprised about 11% of total U.S. energy consumption in 2015 (PDF).
Geothermal energy comes from the earth’s heat, which is captured as steam or hot water and converted into energy. Most geothermal resources are found along the boundaries of tectonic plates and manifest themselves as volcanoes, hot springs, or geysers. California produces more geothermal energy than any other state, accounting for 73% of the country’s total geothermal output in 2015.
Many sites for potential geothermal development are on federal land; currently, about 40% of U.S. geothermal energy capacity is on leased federal lands. Advances in extraction methods and technology could result in new sources of geothermal energy.
See where geothermal energy production happens.
Solar energy can be generated in two ways: by converting solar radiation into heat and electricity via photovoltaic panels or by using the sun’s radiation to heat a fluid and produce steam for a power generator. California leads the country in producing solar energy, producing 56% of the nation’s solar energy in 2015, followed by Arizona, which produced 13%. As of 2014, California is the first state to receive 5% or more of its electricity from solar energy sources.
The solar industry has experienced rapid growth in the past decade due to government programs such as tax credits and state renewable portfolio standards, increased public awareness of its environmental benefits, and decreasing technology costs. Manufacturing costs for solar panels have decreased, and private industry has created better batteries to store solar energy. In southwestern states, solar radiation levels are some of the best in the world for solar energy production. Currently, there are 70 pending applications to develop solar energy projects on federal lands.
See areas of the U.S. with solar energy potential.
Wind power takes advantage of daily wind cycles to rotate wind turbines, which can be clustered together on wind farms. In 2013, wind power accounted for 2% of total U.S. energy production. Texas (44.9 GW hours), Iowa (17.9 GW hours), Oklahoma (14 GW hours), and California (12.3 GW hours) are leading producers.
No offshore wind projects have been completed to date. The National Renewable Energy Laboratory estimated in 2012 that there is enough wind energy potential offshore to generate four times the electricity held by the U.S. power grid. While wind speeds off the Atlantic Coast and in the Gulf of Mexico are lower than in the Pacific, the presence of shallower waters in the Atlantic makes developing wind projects there more affordable in the short term. To date, the Bureau of Ocean Energy Management (BOEM) has issued nine commercial wind energy leases on the Atlantic Outer Continental Shelf, including those offshore of Delaware, Maryland, Massachusetts, Rhode Island, and Virginia. BOEM expects to hold lease sales for areas offshore of New Jersey and North Carolina in the near future and is considering a number of other commercial wind energy planning areas.
See a map of current wind power capacity, potential onshore power, and potential offshore power.
Nonenergy minerals include base and precious metals, industrial metals, and gemstones, amongst others. The 2016 USEITI Report focuses on nonenergy minerals, specifically gold, copper, and iron. In 2015, these minerals accounted for most of the valuable metal produced in the United States, which totaled $26.6 billion (PDF). Copper and gold both accounted for 29% of the total value, while iron made up 14% of the total worth of metal extracted.
Exploration for nonenergy minerals in the United States declined by 6% from 2014 to 2015 (PDF). In 2015, six of the nine major exploration sites for nonenergy minerals in the U.S. concentrated on gold in Nevada (PDF).
Gold can be found in both loose materials and hard rocks. Miners extract gold from placer mines using sluicing, dredging, jigging, and amalgamation devices that separate the gold from water, silt, rock, and other compounds. Lode mining, both open pit and underground, extracts gold embedded within rock walls. Once mined, gold is used to make jewelry, electronics, dental treatments, and other products.
In 2015, the majority of U.S. gold came from Nevada (162,000 kilograms) and Alaska (28,000 kilograms) (PDF). In the United States, recent exploration for gold resulted in discoveries along the Carlin and Battle Mountain-Eureka (Cortez) trends in Eureka and Elko Counties, as well as in the Pequop Mountains in Elko County.
Copper is found in hard rocks in the form of copper ore. Miners extract copper from open pit and underground mines through traditional quarrying to separate the copper from rock, or leaching which involves treating the ore with diluted sulfuric acid. Once produced, copper has a variety of uses, including as a building material, as an effective conductor of electricity, and within the health care sector.
In 2015, Arizona accounted for the most copper production out of all U.S. states with 963,000 metric tons (PDF). The U.S. had the forth largest copper exploration budget in the world.
Iron is found in underground rocks. Miners extract iron by drilling holes in the ground in carefully engineered patterns and blasting out rocks with explosives. Next, miners crush the rocks and separate out the iron ore from other materials. Almost all iron is used to make steel, which in turn is used to make buildings, infrastructure, machines, and vehicles.
In 2014, 93% of the iron ore shipped in the U.S. came from Minnesota and Michigan (PDF), and had an estimated value of $5.1 billion. Exploration for iron decreased in Minnesota from 2014 to 2015, dropping from 57 exploratory holes drilled in 2014 to eight holes drilled in 2015.