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A case study analysis by Norwegian company Over Easy Solar has revealed that vertical rooftop solar panels outperform conventional rooftop PV systems during snowy months. Energy yield was up to 30% higher in the winter months in Norway, according to the company. Vertical rooftop solar panels outperform conventional systems during snowy months, Norwegian company Over Easy Solar has found. The company, which makes vertical PV units, said it conducted a research case study in Oslo, and that the performance of the vertical panels remained consistent through early spring, even after fresh snowfall. “Our data shows that the annual energy yield of vertical solar panels can be equal to or up to 30% higher than that of conventional solar installations on flat roofs,” founder and CEO Trygve Mongstad told pv magazine . “During the winter months in Norway, the energy generated is three to four times higher for vertical solar panels than for conventional solar installations on flat roofs.” The company explained that the vertical panels work best in low snow cover, up to 10 cm, and in partial snow cover, up to 30 cm. When the snow cover is low, they benefit from the increased albedo due to the snow; when the snow cover is partial, the panels continue to capture sunlight while sticking out of the snow. “The snow-covered portion will not produce anything, but the way Over Easy Solar’s ??solar panels are designed, partial snow coverage will not greatly affect the output of the uncovered portion of the solar panel,” the company explains. “However, vertical solar panels that are completely covered by snow will not produce any electricity, just like conventional tilted solar panels.” Another advantage of vertical panels in snowy conditions, according to the company, is the faster melting of snow around them. This is because the orientation of the panels encourages the mixing of warmer air into the snowy surface. In addition, they say, vertical panels capture heat when the sun shines, which speeds up the melting of adjacent snow. “In addition, vertical panel solar installations are less likely to damage the roof membrane or insulation that is often used in cold climates,” Mongstad adds. “Our product was developed with the needs of solar installers and building owners in mind, after my team and I have worked with flat roof solar installations in Norway for many years.” In August, Over Easy commissioned what it describes as the world’s largest vertical bifacial rooftop solar installation to date. It was installed on Norway’s national football stadium. The 284.4kW system features 1,242 vertical PV units of 200W each supplied by Over Easy itself. Over Easy Solar’s ??XM-2 Quattro-200S vertical panels incorporate silicon heterojunction cells and a modular architecture that reportedly offers 95.7% bifaciality. The panels are also claimed to be lightweight, weighing less than 11kg/m2. It has also deployed a 102 kW installation covering 1,200 m2 on a flat-roofed commercial building in Oslo. Over Easy has a novel all-in-one low-rise system design for flat roofs. Its systems are delivered to the installation site in a single pre-assembled unit that includes its unconventional heterojunction bifacial modules, mounting frame and cabling. The company calls its prefabricated product a “vertical photovoltaic unit (VPV)” and each has an output of 200 W. They come in two sizes, one for green roofs, measuring 1,600 mm x 1,500 mm x 345 mm and weighing 26 kg, and one for bare roofs, measuring 1,600 mm x 1,500 mm x 265 mm and weighing 25 kg. The clearance of both products is 120 mm and 40 mm respectively. |
