Czech utility CEZ Group has completed construction on a 22kW, pilot floating photovoltaic project on the upper reservoir of its pumped-hydro storage power plant in Štěchovice, in Central Bohemia.

The pilot facility is located at different heights during the charge and recharge cycles of the pumped-hydro plant and the difference in height may reach up to nine meters.

The east-west oriented photovoltaic system was built with air-filled floats with a carrying capacity of over six tons. The floats, and several rails attached to the walls of the pumped-hydro facility, are intended to maintain the system stably against adverse weather conditions and the water's vertical movement, CEZ Group said in a statement.

“There are great expectations for the deployment of photovoltaics on suitable water areas but only reality will show what we can achieve in Czechia,” it further explained. “If the pilot installation in Štěchovice will convince us, we would like to increase its output five times in the summer,” said Jan Kalina, member of the board of directors and director of CEZ's renewable and classic energy division.

The Štěchovice pumped-hydro storage facility is able supply a total of 200MWh of electricity in four hours and thus help stabilize the Czech energy system. Built in 1947 and then modernized in 1996, the plant can run at 100% capacity in just three minutes.

The CEZ Group currently owns and operates 126MW of PV capacity in Czechia. In November, it acquired German solar developer Belectric from RWE for an undisclosed sum. In September 2019, it invested €10 million in Zolar, a German start-up offering digital solutions for rooftop PV. All CEZ Group's Czech plants were deployed in 2009 and 2010, when a FIT scheme for large scale solar was in place.

The group also operates in Germany, Hungary, Poland, Romania, Slovakia and Turkey.