Energy conversion efficiency

Energy conversion efficiency is the ratio, denoted eta, between the useful output of a machine that converts energy and the energy fed into it, expressed on a scale from 0 to 1. Both the input and the useful output can take the form of chemical energy, electric power, mechanical work, light or heat, and whatever is not converted into the desired useful form is typically rejected as waste heat. The basic formula is output power divided by input power, and because efficiency cannot exceed 100 percent without implying a perpetual motion machine, it is treated as a strict technical limit rather than a target that can be surpassed. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/