The National Academies: What You Need To Know About Energy

The National Academies

What You Need To Know About Energy

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Home & Work

We use energy in homes and commercial buildings in similar ways. We keep rooms at comfortable temperatures, provide lighting, heat water for bathing and hand washing, and power computers, copiers, appliances, and other technologies. Many of these luxuries weren’t even possible 100 years ago—and they require a lot of energy. In 2008, 41% of all the energy consumed in the United States went to powering homes and commercial buildings.

Many of these luxuries weren’t even possible 100 years ago—and they require a lot of energy.

Whether you live in an apartment, townhouse, or a single-family home, chances are you want to keep it warm in cold weather. Data from 2006 show that space heating accounts for the greatest energy usage in the residential sector, with the rest devoted, in decreasing proportions, to appliances, water heating, and air-conditioning. At 7%, electronics usage surpasses washers/dryers and dishwashers, cooking, and computers in energy use. Appliances such as refrigerators, water heaters, and washers/dryers are all considerably more energy efficient than they used to be, thanks to legislation that requires appliances to meet strict standards.

In U.S. homes, natural gas is the most widely used energy source (49%), followed by the secondary energy source, electricity, at 39%. That’s reversed in commercial buildings, where electricity (55%) is depended on more than natural gas (32%). The commercial sector includes a broad array of building types, including offices, grocery stores, sports arenas, schools, shopping malls, hotels, and hospitals. Practically any space where groups gather falls into this economic sector. The energy needs for these different buildings vary but when viewed as a whole, more than half of the energy used in commercial buildings goes to just heating (36%) and lighting (21%). Within this sector, retail stores and service buildings use the most total energy (20%), followed by office buildings (17%) and schools (13%).

For a fuller picture of energy use in these sectors, explore Our Energy System.

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Energy Hands-on

What do you know about energy?

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.

Energy Defined

Kilowatt Hour (kWh)

A unit of measure for energy, typically applied to electricity usage. It is equal to the amount of energy used at a rate of 1000 watts over the course of one hour. One kWh is roughly equal to 3,412 British Thermal Units (Btu).

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National Academies Press

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