The National Academies

The National Academies: What You Need To Know About Energy

What You Need To Know About Energy

What do you know about energy?

Which of the following is not a primary energy source?

  • Sorry, that’s incorrect.

    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.

  • Sorry, that’s incorrect.

    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.

  • Correct!

    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.

  • Sorry, that’s incorrect.

    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.

  • Sorry, that’s incorrect.

    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.

On average, which is most efficient in coverting heat into electic power?

  • Sorry, that’s incorrect.

    On average, a typical coal-burning power plant in 2013 was about 33% efficient in converting heat energy into electrical power. A gas-fired plant was about 42% efficient. And in natural gas combined-cycle power plants—in which waste heat from a natural gas turbine is used to power a steam turbine—generation may be as much as 60% efficient.

  • Sorry, that’s incorrect.

    On average, a typical coal-burning power plant in 2013 was about 33% efficient in converting heat energy into electrical power. A gas-fired plant was about 42% efficient. And in natural gas combined-cycle power plants—in which waste heat from a natural gas turbine is used to power a steam turbine—generation may be as much as 60% efficient.

  • Correct!

    On average, a typical coal-burning power plant in 2013 was about 33% efficient in converting heat energy into electrical power. A gas-fired plant was about 42% efficient. And in natural gas combined-cycle power plants—in which waste heat from a natural gas turbine is used to power a steam turbine—generation may be as much as 60% efficient.

Which of the following energy sources releases carbon dioxide when burned?

  • Sorry, that’s incorrect.

    Gasoline, diesel fuel, and natural gas all release CO2 when burned.

  • Sorry, that’s incorrect.

    Gasoline, diesel fuel, and natural gas all release CO2 when burned.

  • Sorry, that’s incorrect.

    Gasoline, diesel fuel, and natural gas all release CO2 when burned.

  • Correct!

    Gasoline, diesel fuel, and natural gas all release CO2 when burned.

In 2014, of the four economic sectors, which used the most energy in the United States?

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Correct!

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

  • Sorry, that’s incorrect.

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

What is the largest reservoir of stored solar energy?

  • Sorry, that’s incorrect.

    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. 

  • Sorry, that’s incorrect.

    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. 

  • Correct!

    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. 

How efficient are ordinary commercial solar cell units?

  • Sorry, that’s incorrect.

    As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

  • Sorry, that’s incorrect.

    As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

  • Correct!

    As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

  • Sorry, that’s incorrect.

    As of 2014, the very best experimental units could convert more than 40% of light energy to electricity; ordinary commercial units are in the range of 5% to 20%. 

What type of transportation uses the most total energy?

  • Correct!

    By far the largest share of energy in transportation is consumed by cars, light trucks, and motorcycles—about 58% in 2012, followed by other trucks (21%), aircraft (9%), boats and ships (3%), and trains and buses (3%). Pipelines account for 3% and military uses for 2%.

  • Sorry, that’s incorrect.

    By far the largest share of energy in transportation is consumed by cars, light trucks, and motorcycles—about 58% in 2012, followed by other trucks (21%), aircraft (9%), boats and ships (3%), and trains and buses (3%). Pipelines account for 3% and military uses for 2%.

  • Sorry, that’s incorrect.

    By far the largest share of energy in transportation is consumed by cars, light trucks, and motorcycles—about 58% in 2012, followed by other trucks (21%), aircraft (9%), boats and ships (3%), and trains and buses (3%). Pipelines account for 3% and military uses for 2%.

  • Sorry, that’s incorrect.

    By far the largest share of energy in transportation is consumed by cars, light trucks, and motorcycles—about 58% in 2012, followed by other trucks (21%), aircraft (9%), boats and ships (3%), and trains and buses (3%). Pipelines account for 3% and military uses for 2%.

  • Sorry, that’s incorrect.

    By far the largest share of energy in transportation is consumed by cars, light trucks, and motorcycles—about 58% in 2012, followed by other trucks (21%), aircraft (9%), boats and ships (3%), and trains and buses (3%). Pipelines account for 3% and military uses for 2%.

Renewable energy (solar, wind, geothermal, hydroelectric, biofuels, waste, and wood) accounted for what percentage of the total energy supply in the United States in 2014?

  • Correct!

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

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

True or False: Burning coal in electric power plants is a major source of CO2 and other emissions. However, its use doesn't have negative consequences beyond the emissions caused by combustion.

  • Sorry, that’s incorrect.

    Mining coal disturbs the land and modifies the chemistry of rainwater runoff, which in turn affects stream and river water quality.

  • Correct!

    Mining coal disturbs the land and modifies the chemistry of rainwater runoff, which in turn affects stream and river water quality.

Place this badge on your facebook page to show your friends what you know about energy.

Get the badge

Place this badge on your facebook page to show your friends what you know about energy.

Get the badge

OR, get a higher score to unlock a different badge.

Retake the quiz

Place this badge on your facebook page to show your friends what you know about energy.

Get the badge

OR, get a higher score to unlock a different badge.

Retake the quiz

Explore Other Topics

Energy Hands-on

The Promise of Better Lighting

Energy savings through lighting technology

Energy Defined

Natural Gas Combined Cycle (NGCC)

A process which helps improve the efficiency of natural gas power plants by capturing some of the waste heat given off by the combustion of natural gas in order to turn a steam turbine to generate electricity.

View our full glossary