The future of solar cells cheaper, more flexible

Part four of four in the e-glass green series. Read part one, part two and part three.

The United States lags behind countries in Europe and Japan in use of building integrated photovoltaics, says Steven Strong, founder of Solar Design Associates Inc. in Harvard, Mass. High costs and the lack of flexibility in the shape and size of photovoltaic panels make the technology unappealing for many building owners and architects.

Building integrated photovoltaics cost about $80 per square foot, compared to an average of $3 per square foot for a traditional annealed insulating unit with clear glass.

The cost of solar technology remains prohibitive for many owners, says Patrick Boucher, western regional sales manager for Vistawall Architectural Products of Terrell, Texas. “It takes a building owner who is willing to be in it for the long haul, and we’re finding that’s not happening in the private sector,” Boucher says.

Part of the cost difficulty is that the United States has smaller federal incentives for use of BIPV.

“The U.S. has been sleepwalking over the past decade while Europe and Japan have been ramping up their programs,” Strong says. “The [federal] incentives don’t come close to other countries, but there has been a significant change.”

These changes surround the increased use of thin-film solar technology, where a film is applied to glass or stainless steel in a process similar to that for low-emissivity coatings.

While thin film modules are not as efficient as traditional silicone cells, thin films provide the industry with a less-expensive and more design friendly alternative to traditional silicone based cells.

Developments with copper indium selenide thin films could reduce the cost of photovoltaics even more, says Steve Coonen, vice president of sales for Open Energy of Solana Beach, Calif.

In the CIS process, a thin film is applied to stainless steel foil sheets. The sheets are cut into rectangles and laminated between glass layers. “This is an opportunity to cut the cost of cells in half,” Coonen says.

In addition CIS thin films provide flexibility in size and shape, something that photovoltaics have lacked in the past, Coonen says.

“We take the cells—the individual wafers—and then put them between sheets of glass,” Coonen says. “And we can have the glass cut to any size. This is new and exciting for the industry, being able to make custom glass photovoltaic laminates for the building trades.”

Other developments in the thin film industry will provide architects and owners with more options, Strong says. Changes set to occur in the manufacturing process by the end of the year also will allow for increased lite sizes. 

“The manufacturing process is ramping up to make larger pieces,” Strong says. “BIPV will be able to be used in applications that architects envision.”

The specific changes to the manufacturing process include a thin film laser etch material, amorphoussilicone, Strong says.

-By Katy Devlin, e-Newsletter Editor, e-glass weekly