Energy Efficiency

Efficiency is a broad concept that refers, in general, to the elimination of waste. The efficiency of a system is measured as a ratio of the useful work it produces to the energy resources it consumes; a system becomes more efficient as the ratio approaches 1. Energy efficiency is a term used to describe using less energy to do the same amount of work; the corollary of increased energy efficiency is therefore increased productivity (using the same amount of energy to do more work).

Energy efficiency is often treated as a resource in itself, with the rationale that saving a unit of energy is functionally just as effective as (if not superior to) producing an extra unit of energy. Energy efficiency tends to be the easiest resource in which to invest, politically and economically speaking, as it generally costs less to save energy than to generate it, and financial payback for efficiency measures can be substantial. Read more.