State of solar glass in Germany

Sahely Mukerji
November 26, 2008

Solar as a trend has so far been mainly in Europe, says Russell J. Ebeid, president, Glass Group, Guardian Industries Corp., Auburn Hills. Mich. “Europeans have always been into use of glass of unique nature; whereas U.S. is more vanilla [in its use of unique glass], not exotic,” he said. “And that’s because the builders in the U.S. don’t pay for exotic.” The U.S. is starting to wake up as far as solar power is concerned, he said.

“Solar energy is enjoying a strong and continuous growth the last few years [in Europe],” said Jeroen Schotsaert, product manager, Thin Film PV Solar Glass, AGC Flat Glass, Belgium. The different segments, concentrated solar power (CSP or solar mirrors), solar thermal (hot water) and solar photovoltaics (PV) are all seeing an upward trend. “Today crystalline silicon (c-Si) is the mainstream technology in photovoltaic applications,” he said.

In his presentation, Architecture and Photovoltaics, Oct. 23, at glasstec, Dusseldorf, Germany, Ingo Hagemann, architect and consultant, Hagemann Architects & BIPV Consultants, talked about the state of the photovoltaic industry in Germany. (Click here to read about the state of the photovoltaic industry in the U.S.)

“Photovoltaic is a booming industry, with a growth rate of 10 percent,” Hagemann said. “The question is do buildings need photovoltaics?”

Buildings need to be energy savers, not energy users, Hagemann said. “Save energy, increase energy efficiency and use active solar systems, such as PVs,” he said. “The ‘gold’ of our future is solar active building envelopes.”

In addition to producing electricity, PVs have many benefits, Hagemann said. “They provide weather protection, heat insulation, sun protection, noise protection, modulation of daylight, solar thermal advantages, protection against invaders, operate as a radio transmitter for cell phones and power decentralized systems such as motion controls, emergency lights, sun blinds, etc.” PVs can be integrated as roof tiles, pre-fabricated roofs, in facades or glued to the cladding. “The entire architecture of a building can adapt to the solar modules,” he said.

To achieve that, PVs need to be integrated in a building as building integrated PVs. A successful building integration of PVs would involve a symbiosis of three components: building construction issues, aesthetical issues and electrical issues, Hagemann said. PVs can be directly integrated into the building skin or could be part of a traditional or new building product. They can be used as a design element on a building, designed as large size grid connected PV generators or small stand-alone PV system to power a sun blind. PVs can open up new functions for the building envelope, such as, operating as a planar antenna, Hagemann said.

The question is how do you define BIPV, Hagemann asked. It depends how it is aesthetically integrated in the building concept, he said. “Many people ‘define’ BIPV as a building component with PV that replaces some conventional building product in the building envelope. However this might look very ugly.”

Much BIPV research and product development had been done in Germany 1995-2000, Hagemann said. “After that the interest in BIPV dropped due to the fact that the PV manufactures had difficulty supplying their standard PV modules, since the market was increasing so fast,” he said. “For this reason many companies felt they had no time to deal with the development of BIPV. The prime interest was to make money and to get a return of the investments.”

Also, to enter the BIPV market requires PV manufacturers to leave his/her own field of expertise as a PV specialist and enter a new market of building sector. “This needs extra efforts, time and expertise,” Hagemann said. However, the interest in BIPVs has returned in the last one year.

“PVs are the cornerstone of sustainable design,” Hagemann said. “PV technology and components are mature, but we need to invest more in PV training and transfer technology from research into practice.

“We need to market it differently,” Hagemann added. “So far it’s been used only by people who want to be precursors. Why not advertise PVs on TV?”

E-mail Sahely Mukerji, senior editor, at