Energy Payback Calculator
Calculate how long it takes for a renewable energy system to generate the energy used in its manufacturing.
MWh
MWh
years
Energy Payback Time
1.7 years
Energy Return on Investment15.0 x
Net Lifetime Energy280 MWh
Net Energy Ratio1,400 %
Energy Payback Time vs Embodied Energy (Manufacturing)
How to Calculate Energy Payback Time
Energy payback time (EPBT) measures how long a system must operate to produce the energy used in its manufacture.
Formula
EPBT = Embodied Energy / Annual Production
EROI = Lifetime Production / Embodied Energy
Typical Values
Example Calculation
A solar system with 20 MWh embodied energy producing 12 MWh/year over a 25-year lifespan.
- 01Energy payback: 20 / 12 = 1.7 years
- 02Lifetime production: 12 * 25 = 300 MWh
- 03Net energy: 300 - 20 = 280 MWh
- 04EROI: 300 / 20 = 15x