Germany’s Stadtwerke Waldkirch commissioned a PV system with a nominal output of 245 kw in February on the roof of one of its buildings. Chinese manufacturer Sunman supplied glass-free crystalline modules for the installation and now wants to bring these products to the broader European market.
Thanks to the use of glass fibre-reinforced plastic (GRP), instead of glass, the panels only placed an additional load of 4 kilograms per square meter on the roof. Stadtwerke Waldkirch said that it has been planning to install a PV system on the rooftop since 2011. However, for structural reasons, the titanium roof could not accommodate conventional solar modules, as they would place an additional load on it of at least 15 kilograms per square meter.
As Sunman further explained, its PV panels are particularly lightweight because of patented composite materials it uses to replace the glass panels on the front side. The modules are only about 2 millimeters thick and can be brought to the roof with a total load of 3.5 to 5 kilograms per square meter, and can often be applied simply by gluing.
The modules are thinner and lighter than common glass models, but offer the same durability and performance as standard modules with crystalline silicon cells. In addition to the protective layers on the front and back sides, the panels are laminated on both sides of the solar cells with multiple layers of waterproof polymer composites, Sunman added. They offer a conversion efficiency of around 18%.
There are many flat, nonresidential rooftops throughout Europe with surface areas of about 360 million square meters, Sunman said, citing a study by the Fraunhofer IWES. The company estimates that around 60% of these industrial rooftops cannot reliably support conventional solar modules that weigh between 15 and 20 kilograms per square meter.
“All industrial and commercial enterprises can provide their roofs with solar modules and cover a large part of their electricity needs with solar energy itself,” said Zhengrong Shi, the founder of Sunman.
A solar pioneer, he was the founder of Suntech, which became the largest module manufacturer in the world in 2012. But the company subsequently ran into financial difficulties and was acquired by Shunfeng International Clean Energy in 2014. Shi was CEO of the company until August 2012.
Sunman has already introduced its glass-free modules in Asia, Australia and the United States.