A call to solar cell makers: Aim to reduce your carbon footprint

The thin-film photovoltaic (PV) industry needs to aim not only for grid parity — making solar energy comparable in cost to traditional energy sources — but for green parity, or long-term industry sustainability, as well, according to Linde Gases, a division of The Linde Group.

Linde Gases issued its call in advance of the 24th European Photovoltaic Solar Energy Conference in Hamburg, the industry’s largest conference, scheduled for 21 to 25 September.

As the world tackles climate change and solar energy approaches grid parity, the PV industry should begin to address the carbon footprint of photovoltaic module manufacturing to deliver truly green energy, according to Linde. For example, it says, manufacturers shouldn’t be tempted to adopt lower-cost solutions without considering the overall impact on the long-term sustainability of the industry.

Based on data from the National Renewable Energy Laboratory, the payback time for both crystalline silicon cells and thin-film silicon modules — in terms of CO2-equivalent emissions — is between three and four years, with an aggressive target for thin-film of one-year payback.

Linde is reviewing the entire thin-film manufacturing and supply chain from a materials perspective and has identified the possibility of significant CO2-equivalent emission savings by changing the gas used in the plasma enhanced chemical vapour deposition (PECVD) chamber cleaning process. By using fluorine instead of nitrogen trifluoride (NF3) a greenhouse gas with a global warming potential 17,200 times that of CO2, the CO2 payback time for thin-film PV modules could be cut significantly, possibly by as much as two years, Linde estimates.

“As grid parity becomes ever closer to a reality, we as an industry need to start channelling our efforts towards reducing the carbon footprint of solar cell manufacturing,” said Dean O’Connor, head of electronics market development and technology at Linde Gases Division. “Environmental concerns continue to dominate the global agenda, so green parity is an inevitable important new area of focus for suppliers and manufacturers.”

During the European Photovoltaic Solar Energy Conference, Linde Gases Division plans to bring together industry experts from M+W Zander, Oerlikon, Suniva, Malibu and EuPD Research, to host a seminar, “From grid parity to green parity — sustainability in an era of overwhelming cost pressure.” The programme will explore methods to improve sustainability in manufacturing, and will also feature case studies from current cell and module makers.

The seminar is scheduled for 14:30 to 17:45 CET Thursday, 24 September at the CCH Congress Centre, Hamburg.

Linde provides gas and chemical supplies for more than half of all the industry projects by thin-film silicon solar cell manufacturers. The firm operates in key markets such as Germany, Spain, China, Taiwan and India.