You may have wondered what the energy payback time for photovoltaic panels is. A recent Fraunhofer report answers the question:
There is some debate about what should go in to the accounting of energy inputs to produce panels, but certainly the cost to mine the materials, run the factories, ship the panels to the end user should (and are) included. The energy cost of maintaining the installers could be added in as well, though their energy cost is fixed and maybe should not be charged to the panels.
The Fraunhofer report of 2014, based on data collected between 2010 and 2013, concludes that, depending on the type of panel used and the solar irradiation where installed, that the embodied energy in the panels can be produced by them in two-to-four years. The report also extrapolates that soon the time would drop to one-to-two years, because of panel, manufacturing, and installation efficiencies. The report was done in Europe, using Sicily and Germany as the measured sites. The report shows an irradiation map for Europe, but comparable irradiation maps for the US are available.
With PV panels’ service life expected to be 30 years, the panels’ lifetime energy output should be 10 to 20 times the energy cost to provide them. This is true for panels on your roof, but even more so if bought from a large solar farm, as the energy cost to build them is lower.
If you don’t expect to live where you do for 30 years, no problem. Surveys have shown that each kilowatt installed adds nearly $6,000 to a house’s resale value, very similar to what it cost to install the panels in the first place.
Go ahead, consider photovoltaic panels today, either installed on your own roof or bought through a green electricity provider or community solar program.