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 generators. The pattern of fuel use varies widely by sector. For example, oil provides 93% of the energy used for transportation, but only about 1% 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.

Primary energy includes petroleum, natural gas, coal, nuclear fuel, and renewable energy. Electricity is a secondary energy source that is generated from these primary forms of energy.

Primary energy sources are commonly measured in different units: barrels (= 42 gallons) of oil, cubic feet of natural gas, tons of coal. To compare across fuels, we need to use a common unit of measure. The United States uses Btu, or British thermal units, which measure fuel use by the energy content of each fuel source.

Total U.S. energy use in 2011 was about 97.5 quadrillion (=1015, or one thousand trillion) Btu. One quadrillion Btu, often referred to as a "quad," therefore represents about 1% of total U.S. energy use.

In physical energy terms, 1 quad represents 172 million barrels of oil (about 10 days of U.S. oil use), 50 million tons of coal (enough to generate about 3% of annual U.S. electricity use), or about 1 trillion cubic feet of natural gas (equal to 4% of annual U.S. natural gas use in 2011).

The number of quads used in 2011 from each primary energy source is shown in the pie chart on the left. Petroleum (oil) provides the largest share of U.S. primary energy, followed by natural gas, coal, nuclear energy, and renewable energy (including hydropower, solar, geothermal, wind, and biomass).

Primary energy is used in residential and commercial buildings (including homes, businesses, schools, and churches), in transportation, and by industry. Primary energy is also used to generate electricity. The bar chart shows the amount of primary energy used in each of these sectors. As you can see, electric power generation is the largest user of primary energy, followed by transportation.

The electric power sector uses primary energy to generate electricity, which makes electricity a secondary, rather than a primary, energy source. Nearly all electricity is then used in buildings and by industry. This means that the total levels of energy used by residential and commercial buildings, industry, and transportation are actually higher than the amounts shown on the graphics when electricity is added in.

The lines in the figure below connecting the primary-energy-sources on the left with the demand-sectors on the right summarize the source-sector linkages in the U.S. energy system. For example, because all nuclear energy is used in the electric power sector to generate electricity, and nuclear represents 21% of the primary energy used by that sector, the line between nuclear energy and the electric power sector shows 100% on the nuclear (supply source) side and 21% on the electric power (demand sector) side.

The mix of primary energy sources varies widely across demand sectors. Energy policies designed to influence the use of a particular primary fuel for environmental, economic, or energy security reasons often focus on sectors that are major users of that fuel.

For example, because 71% of petroleum (oil) is used in the transportation sector, where it provides 93% of the total energy used, policies to reduce oil consumption have tended to focus on the transportation sector. These policies usually seek to increase fuel efficiency or promote alternative fuels. Ninety-one percent of coal, but only 1% of oil, is used to generate electricity, suggesting that policies affecting electricity generation are likely to have a much larger impact on coal use than oil use.

Some primary energy sources, such as nuclear and coal, are entirely or predominately used in one sector. Others, like natural gas and renewables, are more evenly distributed across sectors. Similarly, while transportation is almost entirely dependent on one fuel (oil), electric power uses a variety of fuels.

Linkages between fuels and sectors can and do change over time, but the change tends to occur slowly. For example, coal was once used extensively as a fuel for heating homes and commercial buildings, but that use has dwindled to almost nothing in the United States over the past half-century. Although renewable energy is still relatively small as a share of total primary energy in the transportation and electric power sectors, its role has been growing.

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How much of our electricity is generated from renewable sources?

U.S. power plants used renewable energy sources — water (hydroelectric), wood, wind, organic waste, geothermal, and sun — to generate about 12% of our electricity in 2012.

Renewable energy sources provided about 12% of total U.S. utility-scale electricity generation in 2012. The largest share of the renewable-generated electricity came from hydroelectric power (56%), followed by: wind (28%), biomass wood (8%), biomass waste (4%), geothermal (3%), and solar (1%).

Electricity generation from renewable resources is primarily a function of generation capacity and the availability of the resource. The history of electricity generation has been different for each renewable source.

Nearly all of the hydroelectric capacity was built before the mid-1970s, and much of it is at dams operated by federal government agencies.Biomass waste is mostly municipal solid waste which is burned as fuel to run power plants. Most of the electricity from wood biomass is generated at lumber and paper mills. These mills use their own wood waste to provide much of their own steam and electricity needs. The amount of installed wind generation dramatically increased in the past decade, due in part to Federal financial incentives and State government mandates, especially renewable portfolio standards.Unlike other renewable sources, a significant amount of solar power is generated by small-scale, customer-sited installations like rooftop solar (or, distributed generation). According to the Annual Energy Outlook 2013, these small solar facilities are projected to generate an estimated 14.13 billion kilowatthours of electricity in 2013.1The contribution of renewable sources to electricity generation has evolved differently for each state. See related articles — Today in Energy, May 2, 2012 and May 3, 2012

Hydroelectric generation increases in some years and decreases in others, primarily due to variation in the amounts of rainfall and melting snowfall occurring in watersheds where major hydroelectric dams are located. The availability of biomass (wood and waste) and geothermal energy is generally consistent over the short term as is the generation from these resources. The availability of wind and solar energy has daily and seasonal patterns, so resulting generation fluctuates widely.

China leads the world in total electricity generation from renewable energy due to its recent massive additions to hydroelectric capacity, followed closely by the United States, Brazil, and Canada. However, the United States produces the most electricity from non-hydroelectric renewable sources, followed by China and Germany.

Although most renewable energy power plants have less environmental impact than fossil and nuclear power plants, there are two main reasons why we don't use more renewable energy.

Renewable Energy Technologies Are Often Expensive: Renewable energy power plants can be more expensive to build and to operate (in terms of dollars per unit of electricity output) than natural gas or even coal plants. Renewable Resources Are Often Geographically Remote: Many renewable resources are available only in remote areas, and building transmission lines to deliver power to large metropolitan areas is expensive.

Three kinds of policies to increase the use of renewable energy are:

Tax credits: The Renewable Electricity Production Tax Credit, a federal incentive, has encouraged a major increase in generation from wind and other eligible renewable sources. Targets: Many states have Renewable Portfolio Standards (RPS), which require electricity providers to generate or acquire a certain portion of their power supplies from renewable sources. However, many RPS programs have "escape clauses" if renewable generation exceeds a cost threshold. See related article — What are renewable portfolio standards and how do they affect generation of electricity from renewable sources? Markets: A number of states have built Renewable Energy Certificates/Credits (RECs) into their Renewable Portfolio Standards. This allows electricity providers to sell renewable energy certificates/credits. Some states have made REC markets mandatory, requiring electricity providers to produce or acquire renewable generation to reduce reliance on fossil fuels to generate electricity. (Detailed information on federal and state renewable energy policies are available from the Database of State Incentives for Renewables & Efficiency.)

1See Generation of Solar Photovoltaic under End-use Generators in Appendix Table A16 of the Annual Energy Outlook 2013.

Generation from wind increased from about 6 billion kilowatthours in 2000 to about 140 billion kilowatthours in 2012. Improved technology has decreased the cost of producing electricity from wind, and growth in wind power has been encouraged by policies that support the use of renewable energy sources.

Hydropower provides more electricity than all other renewable sources combined.

Generation from nonhydropower renewables has more than doubled since 1990.

Renewable Portfolio Standards require electricity providers to generate or acquire a percentage of generation from renewable sources.

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How much of our electricity is generated from renewable sources?

U.S. power plants used renewable energy sources — water (hydroelectric), wood, wind, organic waste, geothermal, and sun — to generate about 12% of our electricity in 2012.

Renewable energy sources provided about 12% of total U.S. utility-scale electricity generation in 2012. The largest share of the renewable-generated electricity came from hydroelectric power (56%), followed by: wind (28%), biomass wood (8%), biomass waste (4%), geothermal (3%), and solar (1%).

Electricity generation from renewable resources is primarily a function of generation capacity and the availability of the resource. The history of electricity generation has been different for each renewable source.

Nearly all of the hydroelectric capacity was built before the mid-1970s, and much of it is at dams operated by federal government agencies.Biomass waste is mostly municipal solid waste which is burned as fuel to run power plants. Most of the electricity from wood biomass is generated at lumber and paper mills. These mills use their own wood waste to provide much of their own steam and electricity needs. The amount of installed wind generation dramatically increased in the past decade, due in part to Federal financial incentives and State government mandates, especially renewable portfolio standards.Unlike other renewable sources, a significant amount of solar power is generated by small-scale, customer-sited installations like rooftop solar (or, distributed generation). According to the Annual Energy Outlook 2013, these small solar facilities are projected to generate an estimated 14.13 billion kilowatthours of electricity in 2013.1The contribution of renewable sources to electricity generation has evolved differently for each state. See related articles — Today in Energy, May 2, 2012 and May 3, 2012

Hydroelectric generation increases in some years and decreases in others, primarily due to variation in the amounts of rainfall and melting snowfall occurring in watersheds where major hydroelectric dams are located. The availability of biomass (wood and waste) and geothermal energy is generally consistent over the short term as is the generation from these resources. The availability of wind and solar energy has daily and seasonal patterns, so resulting generation fluctuates widely.

China leads the world in total electricity generation from renewable energy due to its recent massive additions to hydroelectric capacity, followed closely by the United States, Brazil, and Canada. However, the United States produces the most electricity from non-hydroelectric renewable sources, followed by China and Germany.

Although most renewable energy power plants have less environmental impact than fossil and nuclear power plants, there are two main reasons why we don't use more renewable energy.

Renewable Energy Technologies Are Often Expensive: Renewable energy power plants can be more expensive to build and to operate (in terms of dollars per unit of electricity output) than natural gas or even coal plants. Renewable Resources Are Often Geographically Remote: Many renewable resources are available only in remote areas, and building transmission lines to deliver power to large metropolitan areas is expensive.

Three kinds of policies to increase the use of renewable energy are:

Tax credits: The Renewable Electricity Production Tax Credit, a federal incentive, has encouraged a major increase in generation from wind and other eligible renewable sources. Targets: Many states have Renewable Portfolio Standards (RPS), which require electricity providers to generate or acquire a certain portion of their power supplies from renewable sources. However, many RPS programs have "escape clauses" if renewable generation exceeds a cost threshold. See related article — What are renewable portfolio standards and how do they affect generation of electricity from renewable sources? Markets: A number of states have built Renewable Energy Certificates/Credits (RECs) into their Renewable Portfolio Standards. This allows electricity providers to sell renewable energy certificates/credits. Some states have made REC markets mandatory, requiring electricity providers to produce or acquire renewable generation to reduce reliance on fossil fuels to generate electricity. (Detailed information on federal and state renewable energy policies are available from the Database of State Incentives for Renewables & Efficiency.)

1See Generation of Solar Photovoltaic under End-use Generators in Appendix Table A16 of the Annual Energy Outlook 2013.

Generation from wind increased from about 6 billion kilowatthours in 2000 to about 140 billion kilowatthours in 2012. Improved technology has decreased the cost of producing electricity from wind, and growth in wind power has been encouraged by policies that support the use of renewable energy sources.

Hydropower provides more electricity than all other renewable sources combined.

Generation from nonhydropower renewables has more than doubled since 1990.

Renewable Portfolio Standards require electricity providers to generate or acquire a percentage of generation from renewable sources.

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.

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 generators. The pattern of fuel use varies widely by sector. For example, oil provides 93% of the energy used for transportation, but only about 1% 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.

Primary energy includes petroleum, natural gas, coal, nuclear fuel, and renewable energy. Electricity is a secondary energy source that is generated from these primary forms of energy.

Primary energy sources are commonly measured in different units: barrels (= 42 gallons) of oil, cubic feet of natural gas, tons of coal. To compare across fuels, we need to use a common unit of measure. The United States uses Btu, or British thermal units, which measure fuel use by the energy content of each fuel source.

Total U.S. energy use in 2011 was about 97.5 quadrillion (=1015, or one thousand trillion) Btu. One quadrillion Btu, often referred to as a "quad," therefore represents about 1% of total U.S. energy use.

In physical energy terms, 1 quad represents 172 million barrels of oil (about 10 days of U.S. oil use), 50 million tons of coal (enough to generate about 3% of annual U.S. electricity use), or about 1 trillion cubic feet of natural gas (equal to 4% of annual U.S. natural gas use in 2011).

The number of quads used in 2011 from each primary energy source is shown in the pie chart on the left. Petroleum (oil) provides the largest share of U.S. primary energy, followed by natural gas, coal, nuclear energy, and renewable energy (including hydropower, solar, geothermal, wind, and biomass).

Primary energy is used in residential and commercial buildings (including homes, businesses, schools, and churches), in transportation, and by industry. Primary energy is also used to generate electricity. The bar chart shows the amount of primary energy used in each of these sectors. As you can see, electric power generation is the largest user of primary energy, followed by transportation.

The electric power sector uses primary energy to generate electricity, which makes electricity a secondary, rather than a primary, energy source. Nearly all electricity is then used in buildings and by industry. This means that the total levels of energy used by residential and commercial buildings, industry, and transportation are actually higher than the amounts shown on the graphics when electricity is added in.

The lines in the figure below connecting the primary-energy-sources on the left with the demand-sectors on the right summarize the source-sector linkages in the U.S. energy system. For example, because all nuclear energy is used in the electric power sector to generate electricity, and nuclear represents 21% of the primary energy used by that sector, the line between nuclear energy and the electric power sector shows 100% on the nuclear (supply source) side and 21% on the electric power (demand sector) side.

The mix of primary energy sources varies widely across demand sectors. Energy policies designed to influence the use of a particular primary fuel for environmental, economic, or energy security reasons often focus on sectors that are major users of that fuel.

For example, because 71% of petroleum (oil) is used in the transportation sector, where it provides 93% of the total energy used, policies to reduce oil consumption have tended to focus on the transportation sector. These policies usually seek to increase fuel efficiency or promote alternative fuels. Ninety-one percent of coal, but only 1% of oil, is used to generate electricity, suggesting that policies affecting electricity generation are likely to have a much larger impact on coal use than oil use.

Some primary energy sources, such as nuclear and coal, are entirely or predominately used in one sector. Others, like natural gas and renewables, are more evenly distributed across sectors. Similarly, while transportation is almost entirely dependent on one fuel (oil), electric power uses a variety of fuels.

Linkages between fuels and sectors can and do change over time, but the change tends to occur slowly. For example, coal was once used extensively as a fuel for heating homes and commercial buildings, but that use has dwindled to almost nothing in the United States over the past half-century. Although renewable energy is still relatively small as a share of total primary energy in the transportation and electric power sectors, its role has been growing.

This post was made using the Auto Blogging Software from WebMagnates.org This line will not appear when posts are made after activating the software to full version.