Electricity is a secondary energy source because it can only be produced from the use of primary energy sources such as coal, natural gas, or nuclear reactions.

Electricity is a secondary energy source because it can only be produced from the use of primary energy sources such as coal, natural gas, or nuclear reactions.

Electricity is a secondary energy source because it can only be produced from the use of primary energy sources such as coal, natural gas, or nuclear reactions.

Electricity is a secondary energy source because it can only be produced from the use of primary energy sources such as coal, natural gas, or nuclear reactions.

Refrigerators are not likely to be used more or less hours in the day, but people are more likely to have more of them if they cost less to operate.

Refrigerators are not likely to be used more or less hours in the day, but people are more likely to have more of them if they cost less to operate.

In the United States, the amount of electricity generated from wind doubled between 2009 and 2014, and now makes up 18% of all renewable energy consumed and almost 2% of total U.S. energy use. 

Biofuels contain carbon and although they may burn “cleaner” than oil-derived fuels, they do not avoid generating carbon dioxide emissions.

For decades, more than half of all residential energy use went  to space heating and cooling; in 1993, it accounted for nearly 60%. But EIA data show that by 2009, that share had dropped to 48%. And in the period 1993 to 2009, energy for appliances, electronics, and lighting rose from 24% to 35%, owing to the proliferation of appliances, as well as trends toward larger TVs and other devices.

Wood and waste biomass, along with biofuels, accounted for about 50% of the U.S. renewable energy supply in 2014, and more than 4% of all energy consumed. 

Wood and waste biomass, along with biofuels, accounted for about 50% of the U.S. renewable energy supply in 2014, and more than 4% of all energy consumed. 

Wood and waste biomass, along with biofuels, accounted for about 50% of the U.S. renewable energy supply in 2014, and more than 4% of all energy consumed. 

Fossil fuels represent the largest source of stored solar energy, resulting from the transformation of biomass over millions of years into oil, natural gas and coal. 

Fossil fuels represent the largest source of stored solar energy, resulting from the transformation of biomass over millions of years into oil, natural gas and coal. 

Consuming the largest amount of energy, space heating accounts for 31% of all residential energy used. Space cooling accounts for an additional 12% of energy usage.

Consuming the largest amount of energy, space heating accounts for 31% of all residential energy used. Space cooling accounts for an additional 12% of energy usage.

Consuming the largest amount of energy, space heating accounts for 31% of all residential energy used. Space cooling accounts for an additional 12% of energy usage.

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot. 

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot. 

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot. 

Battery electric vehicles have only a motor and battery, they recharge from the grid and their carbon emissions depend on the energy used to generate the electricity they use. Hybrid vehicles have both a gasoline engine and an electric motor, and use petroleum onboard when their batteries are exhausted. Some hybrid vehicles can charge from the grid and others cannot.