CEZ is testing the real properties of floating solar panel design for possible deployment in future large parks on the 2 kWp pilot located on the upper reservoir of the Štěchovice pumped-storage power plant. After water is pumped from the River Vltava at night, the pilot plant floats at the highest level of the water surface. On the other hand, when the power system exhausts the capacity of the Štěchovice “battery”, it is almost 9 metres lower.

In the summer, the pilot installation will be expanded into a regular power plant using solar power, with a capacity of 100 kWp. Overall, the upper reservoir could house solar panels with a capacity of up to 2.5 MW.

CEZ sees the potential of water surfaces for the development of photovoltaics and it is now testing what would be possible to implement in domestic conditions. By 2030, CEZ wants to contribute to the transformation of the Czech energy sector into a zero-emission sector, by building up renewable energy sources with a capacity of as much as 6 GW.

At Štěchovice, a jigsaw puzzle in the form of four rows of monocrystalline photovoltaic panels was created, thanks to the cooperation of CEZ Obnovitelné zdroje, PRODECO, and CEZ hydro power plants. The so-called roofs with east-west orientation are held above the surface of the upper reservoir by more than thirty air-filled floats with a capacity of over 6 tones. To withstand the vagaries of the weather and the constant movement of the reservoir level, which is determined by the operation of the pumped-storage power plant, the entire structure is fixed to moving girders mounted on the reservoir walls.

The Štěchovice pumped-storage power plant, commissioned back in 1947 and comprehensively refurbished in 1996, is able to reach 100% capacity within just three minutes from a controller’s order. Thanks to the water dropping on the valley-bottom turbine from the reservoir on Homole Hill, the plant is able to deliver a total of 200 MWh of electricity in four hours, helping to stabilize the Czech power system.