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?

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. 

Refrigerators became 70% more efficient between 1972 and 2001, primarily due to regulation. What is a market response to increased efficiency of refrigerators?

  • Sorry, that’s incorrect.

    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.

  • Sorry, that’s incorrect.

    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.

  • Correct!

    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.

On average, how much solar radiation reaches each square meter of earth?

  • Sorry, that’s incorrect.

    On average, even after passing through hundreds of kilometers of air on a clear day, solar radiation reaches Earth with enough energy in a single square meter to run a mid-size desktop computer-if all the sunlight could be captured and converted to electricity.

  • Correct!

    On average, even after passing through hundreds of kilometers of air on a clear day, solar radiation reaches Earth with enough energy in a single square meter to run a mid-size desktop computer-if all the sunlight could be captured and converted to electricity.

  • Sorry, that’s incorrect.

    On average, even after passing through hundreds of kilometers of air on a clear day, solar radiation reaches Earth with enough energy in a single square meter to run a mid-size desktop computer-if all the sunlight could be captured and converted to electricity.

What is a major reason that the U.S. is exporting more oil in 2014 than in 2005?

  • Sorry, that’s incorrect.

    New technologies for drilling have led to increases in supply of oil in the U.S. in the decade up to 2014.

  • Sorry, that’s incorrect.

    New technologies for drilling have led to increases in supply of oil in the U.S. in the decade up to 2014.

  • Sorry, that’s incorrect.

    New technologies for drilling have led to increases in supply of oil in the U.S. in the decade up to 2014.

  • Sorry, that’s incorrect.

    New technologies for drilling have led to increases in supply of oil in the U.S. in the decade up to 2014.

  • Correct!

    New technologies for drilling have led to increases in supply of oil in the U.S. in the decade up to 2014.

If electricity production wastes between 40 and 65% of the primary energy source, why is it used?

  • Sorry, that’s incorrect.

    Most direct uses of primary energy are limited to generating heat and motion. Electricity, by contrast, is extremely versatile, with a wide range of complex applications. 

  • Sorry, that’s incorrect.

    Most direct uses of primary energy are limited to generating heat and motion. Electricity, by contrast, is extremely versatile, with a wide range of complex applications. 

  • Correct!

    Most direct uses of primary energy are limited to generating heat and motion. Electricity, by contrast, is extremely versatile, with a wide range of complex applications. 

Which has been growing more, energy used by lighting and appliances or energy used for heating and cooling?

  • Correct!

    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.

  • Sorry, that’s incorrect.

    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.

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%. 

Which has been growing more, energy to heat homes or energy to cool homes?

  • Sorry, that’s incorrect.

    Current trends indicate that by 2040 residential buildings will consume up to 28% less energy for heating but about 50% more for cooling. 

  • Correct!

    Current trends indicate that by 2040 residential buildings will consume up to 28% less energy for heating but about 50% more for cooling. 

  • Sorry, that’s incorrect.

    Current trends indicate that by 2040 residential buildings will consume up to 28% less energy for heating but about 50% more for cooling. 

How many gallons of water are required to hydraulically fracture a well, on average in the U.S.?

  • Sorry, that’s incorrect.

    The national average is around 1.5 million gallons per well , according to the EPA.

  • Sorry, that’s incorrect.

    The national average is around 1.5 million gallons per well , according to the EPA.

  • Sorry, that’s incorrect.

    The national average is around 1.5 million gallons per well , according to the EPA.

  • Correct!

    The national average is around 1.5 million gallons per well , according to the EPA.

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

U.S. Department of Energy

A federal agency within the executive branch of the U.S. federal government responsible for the advancement of the national, economic, and energy security of the United States.

View our full glossary