Jennifer's Comments

Thanks Bob! What a difference 46 years makes, huh? :-)

Rogelio:

I hear what you're saying and I think you're right that we have to carefully avoid hyping lab experiments as something that will be available soon. But I do think it's still interesting and important to communicate what's going on in the labs, even though those modules aren't available yet, because they have a traceable impact on the industry (and on science as a whole).

I tried to help set more realistic expectations by including the commercial efficiencies of panels actually available today, according to Photon's last overview in February. Those numbers were independently confirmed by Photon and they're conservative considering that some of then have already grown since then, as ecdfan pointed out. I also emphasized that "Commercial cells lag behind the efficiencies achieved by labs in so-called "champion cells," or best of breed cells, and companies don't expect cells produced in high volume to reach the efficiencies of those top lab cells."

Do you have suggestions for how I can better cover these lab results in the future?

MacAfrican: Good point. This is something that I discuss a bit in Part 2 of this series, which I'm hoping will be posted soon. Kilowatt-hour has indeed become an important metric that many solar developers take into consideration in addition to peak efficiency. In terms of rating and comparing different modules industry wide (not on a per-project basis), researchers say it's harder to figure out what the KWh of a module is going to be because that changes significantly depending on factors -- such as where the module will be installed -- that are out of the manufacturers' control. But, for example, Green said there's consistent evidence that amorphous-silicon panels produce 5-10 percent more kilowatt hours than crystalline-silicon panels with the same rated capacity. Some thin-film companies have been talking about finding a way to standardize the KWh measurement. Still, all the folks I spoke with said that the peak efficiency measurement remains important. Many policies still assess incentives by rated capacity, for example, and peak efficiency remains important in projects aimed at meeting peak demand.

Rojelio: I will touch on this issue in Part 2 of this series, which will be posted here soon. For multijunction concentrator cells, Spectrolab says it has been able to bring lab cells to the market in about two years. The times vary among technologies and companies, of course, and commercial efficiencies are never expected to reach the ultimate top lab efficiencies -- and then you lose more efficiency when the cells get turned into panels. (Green says about 80 percent of lab cell efficiencies should be achievable at the module level.) I'll work to get more data on this for other technologies soon!

Earth4Energy: Some types of crystalline cells degrade as much as 6 percent in their first few days of illumination, and then their efficiencies stabilize. So a reference to "stabilized efficiency" means the cell was tested after being exposed to that light (instead of before). I hope that helps!