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.

Combustion of gasoline and diesel fuel emits which of the following?

  • Sorry, that’s incorrect.

    All of the above are emitted by vehicles running on gasoline and diesel fuel.

  • Sorry, that’s incorrect.

    All of the above are emitted by vehicles running on gasoline and diesel fuel.

  • Sorry, that’s incorrect.

    All of the above are emitted by vehicles running on gasoline and diesel fuel.

  • Sorry, that’s incorrect.

    All of the above are emitted by vehicles running on gasoline and diesel fuel.

  • Correct!

    All of the above are emitted by vehicles running on gasoline and diesel fuel.

In 2014, how much of the world's CO2 is released by the United States?

  • Sorry, that’s incorrect.

    The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

  • Correct!

    The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

  • Sorry, that’s incorrect.

    The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

  • Sorry, that’s incorrect.

    The United States emits about 18% of the world’s greenhouse gases, behind only China, which accounts for approximately one-quarter of total global emissions. 

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.

What technology was most responsible for increase in lighting efficiency from 45 Im/W in 2001 to 58 Im/W in 2010?

  • Sorry, that’s incorrect.

    Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

  • Sorry, that’s incorrect.

    Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

  • Correct!

    Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

  • Sorry, that’s incorrect.

    Increasing market share of compact fluorescents was primarily responsible for the increased lighting efficiency between 2001 and 2010.

In 2014, approximately how much energy did the United States use, in quadrillion BTUs?

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Sorry, that’s incorrect.

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

  • Correct!

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

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.

Which of the following is considered an obstacle to cars running on hydrogen fuel cells?

  • Sorry, that’s incorrect.

    All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

  • Sorry, that’s incorrect.

    All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

  • Sorry, that’s incorrect.

    All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

  • Correct!

    All of the reasons mentioned are considered obstacles to producing cars that run on hydrogen fuel cells.

Nuclear power provided what percentage of the total U.S. energy supply in 2013?

  • Sorry, that’s incorrect.

    19% of our electricity was generated  by nuclear fuel in 2013. 

  • Correct!

    19% of our electricity was generated  by nuclear fuel in 2013. 

  • Sorry, that’s incorrect.

    19% of our electricity was generated  by nuclear fuel in 2013. 

  • Sorry, that’s incorrect.

    19% of our electricity was generated  by nuclear fuel in 2013. 

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