In the United States, only about one-eighth of the fuel people burn is converted into useful work. For a variety of reasons — losses during transmission of electrical power, simple laws of thermodynamics, friction and other inefficiencies — the other seven-eighths of the energy goes unused.
Note: To comment, Science News subscribing members must now establish a separate login relationship with Disqus. Click the Disqus icon below, enter your e-mail and click “forgot password” to reset your password. You may also log into Disqus using Facebook, Twitter or Google.