Concept
Floating solar or floating photovoltaics (FPV), sometimes called floatovoltaics, are solar panels mounted on a structure that floats on a body of water, typically a reservoir or a lake such as drinking water reservoirs, quarry lakes, irrigation canals or remediation and tailing ponds. A growing number of such systems exist in China, France, India, Japan, South Korea, the United Kingdom, Singapore, and the United States. The systems have advantages over photovoltaics (PV) on land. Water surfaces may be less expensive than the cost of land, and there are fewer rules and regulations for structures built on bodies of water not used for recreation. Life cycle analysis indicates that foam-based FPV have some of the lowest energy payback times (1.3 years) and the lowest greenhouse gas emissions to energy ratio (11 kg CO2 eq/MWh) in crystalline silicon solar photovoltaic technologies reported. Unlike many land-based solar plants, floating arrays can be unobtrusive because they are hidden from public view. They can achieve higher efficiencies than PV panels on land because water cools the panels. The panels can have a special coating to prevent rust or corrosion. The market for this renewable energy technology has grown rapidly since 2016. The first 20 plants with capacities of a few dozen kWp were built between 2007 and 2013. Installed power grew from 3 GW in 2020, to 13 GW in 2022, surpassing a prediction of 10 GW by 2025. The World Bank estimated there are 6,600 large bodies of water suitable for floating solar, with a technical capacity of over 4,000 GW if 10% of their surfaces were covered with solar panels. The costs for a floating system are about 10-20% higher than for ground-mounted systems. American, Danish, French, Italian and Japanese nationals were the first to register patents for floating solar. In Italy the first registered patent regarding PV modules on water goes back to February 2008. The first floating solar installation was in Aichi, Japan, in 2007, built by the National Institute of Advanced Industrial Science and Technology.
