The world’s first hybrid hydro and floating PV power plant opens in Portugal

Α 220-kW PV installation has been deployed on a hydroelectric dam on Portugal’s Rabagão River. This is the first time the two technologies have been used in tandem at utility scale.

The world's first hybrid hydroelectric and solar power installation just started operating in Portugal. Officially inaugurated on July 6, 2017 in Montalegre Municipality in the northern part of the country, the Alto Rabagão dam has been outfitted with 840 floating solar panels, becoming the first project where floating panels work in tandem with a dam's hydroelectric rotors.

The dam has been in use since 1964 and had a total peak capacity of 68 MW, which is now increased by 220 KW. Covering an area of 2,500 m², the pilot installation is expected to generate 332 MWh within its first year of operation, enough to power 100 homes for a year. The station, run by Energias de Portugal (EDP), uses floating photovoltaic cells to collect sunlight during the day allowing hydroelectric power to be saved for use at night and during peak hours.

The panels, made out of recyclable materials, were created by French floating PV specialists Ciel & Terre International (C&T). According to the company, the location was chosen for its challenging level of difficulty, due to its water depth of 60 metres and surface level variation of more than 30 metres. 

Side-benefits

Apart from the fact that the PV panels will allow the plant to save hydropower to compete at peak demand times, their presence will offer even more advantages. First of all, they will partially shield the water which helps to slow evaporation and algae growth and additionally they will reduce waves within the reservoir, cutting down on the erosion of its banks.

Floating solar panels installed on dams

Installing the panels on dams makes plants more profitable and produces more energy. C&T estimates that if only 10 % of the world's 50 largest dams were outfitted with FPV panels, 400GW of solar electricity could be produced. 

If the combination of hydro and floating PV power plants proves successful, then it could also be applied in Brazil, where Energias de Portugal (EDP) operates a large business and where over 70% of power generation comes from hydro plants. This technology could offer a solution to the country's increased electricity demand, which is expected to more than triple by 2050.

Floating solar farms are constantly gaining ground. Last June, the world's largest floating solar farm was connected to the grid in China, whereas the second-biggest project operates on the Queen Elizabeth II reservoir on the outskirts of London since 2016.

Wires stretch from floating solar panels to the Alto Rabagão dam, which produces most of its power with hydroelectric rotors.