Norwegian energy company Statkraft has completed construction on the first 500 kW portion of a 2 MW floating PV project it is developing in Albania.
The first section of the plant was built with 1,536 solar panels, provided by an unnamed manufacturer, and floating membranes supplied by Norwegian specialist Ocean Sun.
“The main technical challenge has been the unorthodox and revolutionary installation method,” Ocean Sun CEO Børge Bjørneklett. “PV installers have always learned not to step on the panels and that is, of course, true when the panel is fixed with the typical four-point clamps and walking on them creates big deflection and mechanical stress in the cells.” According to him, when this happens it may lead to micro-cracking and premature degradation, especially for modules with a polymer back sheet that has relatively low stiffness.
Bjørneklett also explained that, when the panels rest flat on the membrane, it is possible to walk on the dual glass modules since the load is evenly distributed across the surface and there is very little stress on the glass and cells. “The stress localization is completely different, due to the hydrostatic pressure on the backside of the module,” he added. “We have conducted a lot of tests checking power output over time but also more elaborate testing with electroluminescence imaging in the lab.”
Ocean Sun also conducted a detailed, non-linear, finite element analysis of dynamic walking on the panels and the special cooling effect that is obtained via direct heat conduction through the membrane. “This is definitely more effective than the normal air cooling,” Bjørneklett stated.
According to Statkraft, the project is expected to continue its second implementation phase during the second half of 2021, when three more 500 kW floating units will be installed. “After the start of commercial operations of our Banja and Moglice hydropower plants, we are looking into further optimizing these renewable assets,” said Rigela Gegprifti, Statkraft’s country head in Albania. “The Banja Floating Solar Plant is a concrete example for further integration of different resources of renewable energy.”
The 2 MW floating project is being built at a reservoir linked to the Statkraft Banja HPP 72 MW hydropower plant. It will likely sell power to the grid under a regulated tariff. PV projects up to 2 MW in size capacity are eligible for a feed-in tariff under Albanian regulations. However, it is unclear under which criteria the ministry is approving projects.