Other companies, notably Heliovolt and Nanosolar, are in a race to make thin-film panels using copper indium gallium selenide (CIGS) cells. These have shown efficiencies on par with crystalline silicon and can be made on flexible substrates. In comparison with amorphous silicon, CIGS is a relatively difficult material to work with, and no one has been able to create low-cost products consistently in large quantities, says Ryan Boas, an analyst with Photon Consulting, in Boston.
Building integrated photovoltaics (BIPV), especially rooftop applications, would be the biggest market for flexible PV technology, Boas says. That’s because flexible products are inherently very light, in addition to being quick and easy to install. “Imagine carrying a roll of flexible product on the roof and unrolling it,” he says. “Workers are already used to unrolling roofing material.”
But there are hidden risks and costs associated with BIPV, Schmidtke says. “BIPV is often touted as low cost,” she says, “but in actuality, you’ve got greater risk in terms of a watertight system [for roofing materials] or fire risk, and that increases total installation cost.” However, BIPV does have the advantage of being more aesthetically pleasing, which is important to consumers, she says.
So far, Xunlight has raised $40 million from investors. In December, the state of Ohio gave the company a $7 million loan to speed up the construction of a 25-megawatt production line for its flexible solar modules. The company expects to have commercial products available in 2010.