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?

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.

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. 

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%.

The United States is home to how many of the world's automobiles?

  • Sorry, that’s incorrect.

    With less than 5% of the world's population, the United States is home to one-third of the world's automobiles.

  • Correct!

    With less than 5% of the world's population, the United States is home to one-third of the world's automobiles.

  • Sorry, that’s incorrect.

    With less than 5% of the world's population, the United States is home to one-third of the world's automobiles.

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.

Which of the following is not considered to be a drawback to wind energy?

  • Sorry, that’s incorrect.

    While wind energy has many benefits, all of the above are considered drawbacks to wind energy.

  • Sorry, that’s incorrect.

    While wind energy has many benefits, all of the above are considered drawbacks to wind energy.

  • Sorry, that’s incorrect.

    While wind energy has many benefits, all of the above are considered drawbacks to wind energy.

  • Correct!

    While wind energy has many benefits, all of the above are considered drawbacks to wind energy.

Which of the following is emitted by coal-fired power plants?

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Correct!

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

Which of the following is frequently used as a unit of measurement for the energy content of fuels?

  • Sorry, that’s incorrect.

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

  • Correct!

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

  • Sorry, that’s incorrect.

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

  • Sorry, that’s incorrect.

    The British Thermal Unit, or Btu, is frequently used as a measure for energy content of fuels. One gallon of gasoline contains about 124,000 Btu.

What are ways that electricity system operators match power needs to generation on a day-to-day basis?

  • Sorry, that’s incorrect.

    Load-following and peaker plants, demand-response and energy storage are all ways that grid operators can adjust generation to meet demand.

  • Sorry, that’s incorrect.

    Load-following and peaker plants, demand-response and energy storage are all ways that grid operators can adjust generation to meet demand.

  • Sorry, that’s incorrect.

    Load-following and peaker plants, demand-response and energy storage are all ways that grid operators can adjust generation to meet demand.

  • Sorry, that’s incorrect.

    Load-following and peaker plants, demand-response and energy storage are all ways that grid operators can adjust generation to meet demand.

  • Correct!

     

    Load-following and peaker plants, demand-response and energy storage are all ways that grid operators can adjust generation to meet demand.

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