All of the above are emitted from coal-fired power plants and can be harmful to our health and the environment.

All of the above are emitted from coal-fired power plants and can be harmful to our health and the environment.

All of the above are emitted from coal-fired power plants and can be harmful to our health and the environment.

All of the above are emitted from coal-fired power plants and can be harmful to our health and the environment.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

In 2014, 10% of our total energy use came from renewable energy sources, such as biomass, wind, solar, and hydropower.

Tidal energy is gravitational in origin. Solar energy comes from nuclear reactions in the sun.

Tidal energy is gravitational in origin. Geothermal energy comes from radioactive decay inside the earth.

Tidal energy is gravitational in origin. Solar energy comes from nuclear reactions in the sun, and geothermal energy comes from radioactive decay inside the earth.

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.

U.S. energy consumption was about 98 quads in 2014.

U.S. energy consumption was about 98 quads in 2014.

U.S. energy consumption was about 98 quads in 2014.

In 2014, the industrial sector represented 32% of U.S. energy use, while transportation was 28%. Residential and commercial were 22% and 19% respectively.

In 2014, the industrial sector represented 32% of U.S. energy use, while transportation was 28%. Residential and commercial were 22% and 19% respectively.

In 2014, the industrial sector represented 32% of U.S. energy use, while transportation was 28%. Residential and commercial were 22% and 19% respectively.

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. 

A typical incandescent lamp (traditional light bulb) that consumes 60 watts of power produces around 800 lumens. A compact fluorescent lamp emits the same amount of light while using only 13 watts. And an LED lamp consumes only 10 watts to give off the same 800 lumens.

A typical incandescent lamp (traditional light bulb) that consumes 60 watts of power produces around 800 lumens. A compact fluorescent lamp emits the same amount of light while using only 13 watts. And an LED lamp consumes only 10 watts to give off the same 800 lumens.

A typical incandescent lamp (traditional light bulb) that consumes 60 watts of power produces around 800 lumens. A compact fluorescent lamp emits the same amount of light while using only 13 watts. And an LED lamp consumes only 10 watts to give off the same 800 lumens.

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.