Solar power has taken many forms in recent years—from giant concentrated solar power installations and solar towers spread out across deserts worldwide, to rooftop photovoltaic (PV) installations in urban settings, to space-based solar power. A less-frequently installed concept that has nonetheless stayed afloat involves arrays of solar panels that are buoyed on water.
Compared to 2011, when only a handful of developers seemed to be involved in prototype projects, floating solar arrays are skimming waters from Israel to India.
In September, the UK got its first floating array as French firm Ciel et Terre (Sky and Earth) completed installation of about 800 panels mounted on plastic floats on a reservoir at the Sheeplands Far in Berkshire (Figure 4). Ciel et Terre, which has installed its Hydrelio floating solar platform on drinking water reservoirs, quarry lakes, irrigation canals, and remediation and tailing ponds since its first 14-kW prototype was installed in France in 2011, says that the cooling effect of water on PV panels enables its systems to produce more energy than land-based systems of a similar size.
|4. Floating an idea. The Sheeplands Farm in Berkshire in September installed the first floating solar array in the UK. Courtesy: Floating Solar UK
Floating arrays are getting bigger, too. This July, for example, to slash energy expenditures and reduce lost revenues from water evaporation at the same time, the Northern Areas Council that oversees two community wastewater management systems in the state of South Australia installed a floating solar system on five of six water basins, an area covering 34,080 m2. The 3.2-MW solar array, designed to generate 13,690 kWh a day for both systems, uses 12,780 PV modules and technology that is patented by Australian firm GEITS ANZ. The Northern Areas Council says it is saving 14 million gallons of water annually, or realizing a 70% reduction in evaporation. The project was financed through a power purchase agreement with GEITS that required no upfront costs and immediately reduced power charges.
In Japan, floating solar project developers like Kyocera Corp. and Century Tokyo Leasing Corp. plan to build floating arrays to address land constraints. The companies have plans to begin operating 1.7-MW and 1.2-MW arrays in the prefecture of Hyogo in Western Japan in April 2015. This June, Japan completed installation of a 1.18-MW PV system in the city of Okegawa.
India’s National Hydro Power Corp., meanwhile, in July announced plans to build a 50-MW array that would cost between $64 million and $72 million. The project proposed to cover reservoirs and lakes in the southern state of Kerala could see a pilot operating as early as this fall.