"Energy input" refers to the amount of energy that is put into a system or process. It can be thought of as the energy added or required to make something work or function properly. Full definition
In the production of power, nearly two - thirds of energy input from fossil fuels is lost as waste heat. (sciencedaily.com)
Short - term variations in solar energy input have caused climate change in the past and need to be included in any climate model. (illconsidered.blogspot.ru)
If you are in a job that does not require energy input into its processes, let me know, I would like to invest. (scholarsandrogues.com)