Solar Panel Efficiency Records Broken Again?

Do The Math—the nom de plume of UC San Diego physics smart guy Tom Murphy—argues persuasively that we’re all a bit too focused on photovoltaic (PV) efficiency. Even at 15 percent, he says, PV is beating a lot of other energy technologies and “is perfectly adequate for our needs.” But in the hyper-competitive world of solar PV, where a few percentage points improvement could cut costs, boost investor support and improve marketability, the battle for greater efficiency rages on. Alta Devices and Semprius are the latest to claim new efficiency records.

Santa Clara, Calif.-based Alta Devices said its “most recent solar panel has been verified by the National Renewable Energy Laboratory (NREL) at 23.5 percent efficiency.” The company said “this is the highest solar panel efficiency yet achieved and demonstrates Alta’s progress toward its objective of developing solar photovoltaic (PV) solutions that are competitive, without subsidies, with fossil fuels.” Meanwhile, Durham, N.C.-based Semprius said it had “set a new world record for photovoltaic module efficiency, reaching 33.9 percent.” (That’s a Semprius prototype pictured directly below.)

image via NREL

Now, you might have noticed that these two records are quite disparate, with more than 10 percentage points separating them. How can that be? A quick review of the different ways people talk about solar efficiency records explains how.

The first thing to keep in mind is a lot of the efficiency records you hear bandied about are for cell efficiency. Cells are the most basic form of the solar photovoltaic apparatus, the building block, if you will. But to generate usable electricity in a real-world scenario, cells need to be combined to form modules, AKA panels. The efficiencies with panels are inevitably lower than with a single cell.

In this case, both Alta Devices and Semprius were talking about modules/panels, so at least we’re on the same page there. (Last November, we wrote about Alta Device setting a cell efficiency record.)

[source: http://feedproxy.google.com/~r/Earthtechling/~3/c5H1QA18y1M/]