Energy Balance and Energy Ratio
Energy balance and energy payback ratio.
The terms "energy balance" and "energy payback ratio", or "energy ratio", are used to describe system energy output related to system energy input.
The energy balance can be expressed as
Eo = dE + Ei (1)
or
dE = Eo - Ei (1b)
where
dE = energy balance
Eo = energy output
Ei = energy input
The energy ratio - system energy output to system energy input - can be expressed as
ER = Eo / Ei (2)
where
ER = energy ratio
