Abstract
This FAQ sheet discusses the concept of 'energy payback,' or how long a PV system must operate to recover the energy -- and associated generation of pollution and carbon dioxide -- that went into making the system in the first place. Energy payback estimates for rooftop PV systems boil down to 4, 3, 2, and 1 years: 4 years for systems using current multicrystalline-silicon PV modules, 3 years forcurrent thin-film modules, 2 years for future multicrystalline modules, and 1 year for future thin-film modules. With energy paybacks of 1-4 years and assumed life expectancies of 30 years, 87% to 97% of the energy that PV systems generate will be free of pollution, greenhouse gases, and depletion of resources.
| Original language | American English |
|---|---|
| Number of pages | 2 |
| State | Published - 1999 |
NREL Publication Number
- NREL/FS-520-24619
Keywords
- carbon dioxide
- clean energy
- crystalline silicon (x-Si) (c-Si)
- energy payback
- greenhouse gases (GHG)
- photovoltaics (PV)
- pollution
- thin films