How Much Energy Does It Take to Make a Solar Panel?

Recently a customer of ours raised the concern that he had heard: Solar panels will never generate enough power to offset the energy that was used to manufacture them in the first place.

That energy that went into making the panels is called “embodied energy.” After reviewing several websites with very alarmist data, I started looking around some more and found two great resources.

This first paper aggregates and reviews thirteen previously published papers and finds one methodology the most accurate that puts the “energy pay back” of a panel at 2-3 years for one projection, and 6-8 years in a worst case scenario. The biggest draw back to the referenced studies is that they were all performed in the late 90s and early 2000s; before the PV industry saw its great revival.

http://www.energybulletin.net/node/17219

This second study is from 2008. If you scroll down to the conclusion you’ll find:

“According to our analysis, replacing grid electricity with central PV systems presents significant environmental benefits, which for CdTe PV amounts to 89–98% reductions of GHG emissions, criteria pollutants, heavy metals, and radioactive species. For roof-top dispersed installations, such pollution reductions are expected to be even greater as the loads on the transmission and distribution networks are reduced, and part of the emissions related to the life cycle of these networks are avoided.”

and

“PV technologies provide the benefits of significantly curbing air emissions harmful to human and ecological health. It is noted that the environmental profiles of photovoltaics are further improving as efficiencies and material utilization rates increase and this kind of analysis needs to be updated periodically.”

http://pubs.acs.org/doi/full/10.1021/es071763q?cookieSet=1