### Question
What does energy efficiency mean?


### Answer
**Energy efficiency** has the following meaning in *42 U.S.C. § 6311*:

> the ratio of the useful output of services from an article of industrial equipment to the energy use by such article, determined in accordance with test procedures under section 6314 of this title

#### Citation:
  - *42 U.S.C. § 6311*
  - Heading: **CHAPTER 76-AGE DISCRIMINATION IN FEDERALLY ASSISTED PROGRAMS > SUBCHAPTER III-IMPROVING ENERGY EFFICIENCY > Part A&ndash;1-Certain Industrial Equipment**

