Energy payback time
What is Energy payback time?
The time period required by a system to generate capacity sufficient for producing as much useful energy as was consumed during its manufacturing. For example, the energy payback period for a single solar module in Australia is usually under a year. As for the whole rooftop array, the average payback time in this area is less than two years. In general, photovoltaic modules have a payback of 1-3 years in different regions of the planet.