Common Easy to Understand Measures of Solar PV efficiencies
Aug 22, 2011
Recently, the EPA has redesigned car stickers that make it easier for consumers to shop for high efficiency vehicles. I think these stickers can work for both electric and hybrid and conventional vehicles. I read of "breakthroughs" in the solar PV industry almost daily. Often I see a percentage such as "34% efficient." Greater public attention would be generated by these "breakthroughs" if a better metric could be used such as $ per kilowatt hour generated or $5000 array will break-even in X number of months. I am wondering if (a) we could devise a more public friendly metric that would work across PV (and possibly the new PV-hydrogen) technologies and (b) if such a metric would generate more interest from consumers and venture capitalists.
Feb 10, 2012
What about watts per square meter of panel? Or average watt-hours per square meter per day? This would have to be measured over a given period of time, at a few reference amounts of insolation (say 3), and at a specific angle of incidence (say 75 degrees)? I'm sure I'm not the first to think of this -- isn't there some ASTM standard out there for measuring this? The standard should pick a time duration measurement period that captured the true capability of the panel. The other measurement standards should reflect "typical" operating conditions; the three levels of insolation should be chosen to approximate the observed averages at "southern", "mid-latitude", and "northern" U.S. locations (for example, 239, 197, and 156 Wh/m2, respectively). And the angle of incidence should NOT be 90 degrees, but the average angle of incidence over the span of a day for a typical, fixed-mount panel.