Calculadora de Retorno Energético — Fórmula
## 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
- Solar PV: 1-3 years EPBT
- Wind turbine: 0.5-1 year EPBT
- Nuclear: 5-7 years EPBT
- Coal plant: 1-2 years EPBT (but never net-zero CO2)
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
- Solar PV: 1-3 years EPBT
- Wind turbine: 0.5-1 year EPBT
- Nuclear: 5-7 years EPBT
- Coal plant: 1-2 years EPBT (but never net-zero CO2)
Ejemplo Resuelto
A solar system with 20 MWh embodied energy producing 12 MWh/year over a 25-year lifespan.
- Energy payback: 20 / 12 = 1.7 years
- Lifetime production: 12 * 25 = 300 MWh
- Net energy: 300 - 20 = 280 MWh
- EROI: 300 / 20 = 15x