With the definition “floating photovoltaics” we describe those solar power generation plants built on bodies of water instead on land, through floating structures. It is a fast growing market segment: last summer, when the most recent estimates were drawn, there were about 350 plants in 35 countries, including Italy, with an overall capacity of 2,6 GW. There are however already over 60 nations were this kind of plant is been developed, and the growth rate is forecast at 20% in five years.
The popularity of floating photovoltaics is due to multiple factors, beginning with technical ones: water acts as cooling agent for the modules, lowering their temperature and increasing their productivity and duration. A recent article published by Norwegian researches estimates that the panels yield increase between 5% and 7% with water.
The shading provided by the modules then lower the temperature of the underlying water, benefitting the preservation and quality of the water reservoir. A joint research by the Lancaster and Stirling Universities, published in march 2021, revealed that “at scale, (the shading provided by modules) could help to mitigate against harmful effects caused by global warming, such as blooms of toxic blue green algae, and increased water evaporation, which could threaten water supply in some regions”.
Floating plants also allow savings in term of land consumption, by using instead the surfaces of bodies of water which would not have had another use. Moreover, if the modules are positioned on artificial reservoirs by hydroelectric plants, it is possible for the managing companies to benefit from the synergy between the two generation sources.
Floating photovoltaics is usually built in inland bodies of water, where the waters are calm and the risks posed by of tides and currents toward the modules is quite low. However, thanks to the technological advancements an increasing number of solutions for building the plants in the open sea has been developed: there several pilot projects which had already been developed, including a 5 MW one near the coast of Singapore, which entered service last April.
The same attitude toward minimizing the environmental footprint is a key feature of Chiron Energy, an independent renewable power generating company that looks forward to all solutions which allow a lesser use of pristine soil, even on land, like requalifying degraded areas such as abandoned industrial plots or filled-up quarries and landfills. A valid example is set by the plant being built in San Martino di Venezze near Rovigo, where a half-built and long abandoned industrial site will come to new life, with grass growing shaded by of panels.