Last summer, we wrote about Japan's plan to build huge floating solar power plants on reservoirs around the country in order to meet its ambitious renewable energy goals in the wake of the Fukushima disaster. Now, Thames Water has announced that it is building the largest floating solar array in Europe on a reservoir in London. These projects join a growing list of floating solar installations around the world.
At first floating solar arrays seem like a strange idea. Why build them on water when you can build them on land?
There are actually a few good reasons. One is that there are areas where a wide expanse of land is hard to come by, like in Japan where cities are dense and agricultural land is limited, solar takes a backseat when it comes to available space. London is another dense city where solar has to either go on a rooftop or, in this case, on a reservoir.
Another reason is that the water keeps the solar panels cool, which helps the solar panels to perform better and last longer and the water itself benefits from the panels being there. In the case of reservoirs, the panels block out sunlight so it keeps algae growth to a minimum and reduces water evaporation to keep the reservoirs full.
The London project is being constructed on the Queen Elizabeth II Reservoir near Walton-on-Thames and will see 23,000 solar PV panels cover one-tenth of the large body of water, equal to about 8 football pitches. It will have a capacity of 6.3 MW and is expected to generate 5.8 million kilowatt hours in its first year -- roughly the yearly consumption of 1,800 homes.
The electricity generated will help power the nearby water treatment plant and will go towards Thames Water's goal of generating 30 percent of its own energy from renewable sources by 2020.