Building-Integrated PV: New Opportunities for a Bright Future

BIPV has yet to reach its full potential in the U.S., but a couple companies are giving it a shot.

Soltecture's Corium thin-film CIGS BIPV is installed on the company's headquarters in Berlin.

Building-integrated photovoltaics (BIPV)--photovoltaic (PV) modules integrated into functional building elements, such as roofs, glazings, and building façades--are fairly common in Europe and Asia. Yet finding commercial BIPV façade products in the U.S. is nearly impossible. Why is that?

There are a number of possibilities, including lack of suitable new projects due to the economy, a tempestuous PV market, and concerns about reliability and performance, to name a few--but the real reason might be a lot simpler.

Code compliance and bureaucracy

According to Steven Strong, president of Solar Design Associates, architects are not likely to design a façade around a BIPV manufacturer's standard PV panel offerings. The panels usually have to be custom-built for the project, and therein lies the problem.

In Europe, a custom PV panel built in the same manner as the manufacturer's standard-size offerings can be preapproved by CE or TÜV, manufactured, and installed with relatively little fanfare...or expense. Not so in the U.S. John Wohlgemuth, principal scientist in PV reliability at NREL, who also works on PV code compliance, said "You need UL 1703 to put any PV on a building, and UL 1703 says if you make any change in the module you have to reassess it."

This means a PV manufacturer has to get UL 1703 approval for each PV panel size. And if it is a custom panel, then the mounting system and components also need UL approval. It is a time-consuming, expensive process that "is a huge barrier to innovation and implementation," said Strong.

Hope for the future

But change is in the works. Wohlgemuth said that UL 1703 is being modified to better accommodate custom BIPV, and ultimately it will be replaced by IEC61730, which will eliminate the retesting requirement. The modifications to UL 1703 should be ready by the end of 2012, but it will be a couple years before IEC61730 is adopted and BIPV implementation is simplified in the U.S.

Focus Materials now offers UL-approved PV mounting systems for BIPV rainscreens and curtainwalls. A mockup of the product is shown here.

Soltecture and Focus Materials enter the BIPV market

While we wait for IEC61730, the German company Soltecture, formerly Sulfurcell, recently received UL approval for its Corium BIPV and is now offering it for sale in the U.S. The system uses the company's Linion L laminated copper indium gallium diselenide (CIGS) rigid thin-film PV panel adhered to an aluminum "cassette." The cassette attaches to the building's cladding system to give the frameless PV panel the appearance of black architectural glass. CIGS can provide decent performance in indirect light, so it's an appropriate choice for BIPV, which is often not ideally oriented to the sun. Corium is available in one size, 2' x 4', so there will be some design limitations, but it is smaller than most PV panels, so the company claims it should be easier to integrate into a building. And where irregular panels are required, matching black glass is used.

Soltecture's standard, non-Corium panels can also be used along with Focus Materials' UL-approved rainscreen and curtainwall BIPV mounting systems. Focus Material's offers a package that includes materials, gaskets, sealants, PV panels, wiring harnesses, and inverters as well as support.

Rapid industry changes

Over the last year or so, we've been busy trying to stay on top of the ever-changing photovoltaic (PV) industry--Evergreen Solar, BP Solar, and Uni-Solar have all gone out of business--so it is encouraging to see a new player enter the U.S. market, especially the BIPV market.

We've reorganized some of our GreenSpec BIPV sections to reflect the recent changes, and we hope to add more BIPV façade products as U.S. standards catch up with those in the rest of the world.