Energy efficiency may refer to:
- Efficient energy use, sometimes simply called energy efficiency.
- Energy efficiency in transportation.
- Energy conversion efficiency, the ratio between the output and input of an energy conversion machine.
- Energy conservation, efforts made to reduce energy consumption.
Famous quotes containing the words energy and/or efficiency:
“I say, stamping the words with emphasis,
Drink from here energy and only energy,”
—Stephen Spender (1909–1995)
“Nothing comes to pass in nature, which can be set down to a flaw therein; for nature is always the same and everywhere one and the same in her efficiency and power of action; that is, nature’s laws and ordinances whereby all things come to pass and change from one form to another, are everywhere and always; so that there should be one and the same method of understanding the nature of all things whatsoever, namely, through nature’s universal laws and rules.”
—Baruch (Benedict)