Calculateur de Retour Énergétique Gratuit
Calculez le temps de retour énergétique de vos investissements. Estimez quand vos économies d'énergie couvrent l'investissement initial.
Energy Payback Time
1.7 years
Energy Payback Time vs Embodied Energy (Manufacturing)
Formule
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
Exemple Résolu
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
Questions Fréquentes
What is energy payback time?
Energy payback time (EPBT) is the time a system must operate to generate the energy consumed during its manufacture, transport, and installation. Lower is better.
Do solar panels produce more energy than they use?
Yes, by a large margin. Modern solar panels pay back their embodied energy in 1-3 years and then produce clean energy for 22-27 more years. Their EROI is 10-20x.
What is EROI?
Energy Return on Investment is the ratio of energy produced over a lifetime to energy invested in manufacturing. An EROI above 5x is considered good for energy sources.