Energy in Briefs explain important energy topics in plain language. Each Brief answers a question relevant to the public and recommends resources for further reading. Please use the tools to the right to give us feedback, share with others, or sign up for notices as new Briefs are released.
November 20, 2009
Renewable portfolio standards are policies designed to increase electricity generation from renewable resources, including wind, solar, geothermal, and biomass. Many States have their own renewable portfolio standards, although currently there is no program at the National level. States with renewable portfolio programs have seen an increase in the amount of electricity generated from renewable fuels.
October 20, 2009
What is the electric power grid, and what are some challenges it faces?
The grid of electric power lines has evolved into three large interconnected systems that move electricity around the country. Standards have been developed by the electric power industry to ensure coordination for the linked operations. Challenges facing the power grid include getting approval for corridors of land for new transmission lines within States or that cross multiple States, and the financing and constructing of new transmission lines to assure continued reliability of our electricity supply.
August 10, 2009
What is the status of the U.S. nuclear industry?
There are currently 104 commercial nuclear reactors at 65 nuclear power plants in 31 States. Since 1990, the share of the Nation's total electricity supply provided by nuclear power generation has averaged about 20%, with the level of nuclear generation growing at roughly the same rate as overall electricity use. Between 1985 and 1996, 34 new reactors were placed in service. In addition, nuclear generation has increased as a result of higher utilization of existing capacity and from technical modifications to increase nuclear plant capacity (expressed in megawatts). In response to incentives provided by the Energy Policy Act of 2005, nuclear power output is expected to grow, but at a slightly lower rate than total electricity generation.
July 28, 2009
What role does liquefied natural gas (LNG) play as an energy source for the United States?
On an annual basis over the past five years, the United States imported between 13% and 16% of its natural gas requirements. Most of these imports were in gaseous form delivered by pipeline from Canada. However, natural gas imports have also come in liquid form from overseas. Between 1% and 3% of U.S. demand for natural gas was met by LNG in the past five years.
April 23, 2009
What are the major sources and users of energy in the United States?
The major energy sources in the United States are petroleum (oil), natural gas, coal, nuclear, and renewable energy. The major users are residential and commercial buildings, industry, transportation, and electric power generation. The pattern of fuel use varies widely by sector. For example, oil provides 96% of the energy used for transportation, but only 2% of the energy used to generate electric power. Understanding the relationships between the different energy sources and their uses provides insights into many important energy issues.
April 23, 2009
How dependent are we on foreign oil?
The United States imported about 58% of the petroleum, which includes crude oil and refined petroleum products, that we consumed during 2007. About half of these imports came from the Western Hemisphere. Our dependence on foreign petroleum is expected to decline in the next two decades.
April 22, 2009
How much renewable energy do we use?
Americans used renewable energy sources -- water (hydroelectric), geothermal, wind, sun (solar), and biomass -- to meet about 7% of our total energy needs in 2007.
March 12, 2009
How can we compare or add up our energy consumption?
To compare or aggregate energy consumption across different energy sources like oil, natural gas, and electricity, we must use a common unit of measure. This is similar to calculating your food energy intake by adding up the calories in whatever you eat.
January 28, 2009
Who are the major players supplying the world oil market?
Governments of oil-rich countries have a major influence on the world supply of oil through ownership of national oil companies and, for some governments, their membership in OPEC.
September 8, 2008
How much does the Federal Government spend on energy-specific subsidies and support?
The Federal Government spent an estimated $16.6 billion in energy-specific subsidies and support programs in Fiscal Year (FY) 2007. Energy-specific subsidies have more than doubled since FY 1999.
July 10, 2008
What are greenhouse gases and how much are emitted by the United States?
Greenhouse gases trap heat from the sun and warm the planet's surface. Of U.S. greenhouse gas emissions, 87% are related to energy consumption. Since 1990, greenhouse gas emissions in the United States have grown by about 1% per year. In 2005, about 21% of the world's total energy-related carbon dioxide was emitted by the United States.
