Will floating solar PV catch on?
Posted by Alex Barrett on 29 June 2016 at 11:05 am
Large scale solar installations can generate large quantities of green energy for use in industry. However the question of where these power plants should be constructed can be a hot topic. Floating solar panels are becoming increasingly popular, with a large number of new projects being built around the world as we speak. What are the advantages of putting solar panels on water, rather than land? And how much electricity will some of the world’s new floating solar arrays produce?
By their very nature, solar panels have to cover a large area. Rooftop solar arrays have a limited impact on the environment, since a building is going to be placed there anyway. But when large areas of the countryside are set aside for industrial scale solar plants it can raise concerns about land use.
Some sectors of the population are very vocal that fields should be used for farming, not the production of electricity. There is little evidence to support the view that solar panels are having a negative impact on British farming, but this view is pervasive nonetheless. This even led the government to cut subsidies to farmers with solar installations on their land in 2014 [1, 2]. Putting solar panels on farm land doesn’t substantially affect UK food supply, but it is hard to dispute that developing any natural environment for human use is going to have an impact on the wildlife that inhabits it.
One solution to this controversial topic is to set up solar panels on water, rather than on land. Most large population centres get their water from reservoirs. The energy used by the pumps and treatment plants that control our water supply is vast. We don’t often consider how much power it takes to pump our water, even though it is a service we use every time we turn on a tap. Reservoirs cover a substantial area, and are already carefully managed and controlled. Consequently installing rafts of floating solar panels on these sites has a limited impact on wildlife or the environment. By using solar panels to power these facilities we can dramatically reduce the energy demand of bringing us clean water every day.
Floating solar arrays, sometimes dubbed “floatovoltaics”, were initially limited to small installations, mostly located on farms. The trend began in the United States , but the industry has really taken off in the last few years and floating solar panel arrays are now being built in several countries across the world. These solar panels have the potential to be more efficient than land based installations. Solar photovoltaics don’t work as effectively at high temperatures. Waterborne systems have a plentiful supply of water which can be used to cool the panels and prevent overheating. Kyocera, the Japanese energy company behind some of these schemes claims that floating solar panels are 11% more efficient than those built on land .
One example is a massive solar array which has recently been constructed on the Queen Elizabeth II reservoir, which supplies water to a large part of London . A similar scheme is located on the Godley reservoir in greater Manchester [6, 7]. The London project will generate 5.8 million kilowatt hours of energy in its first year of operation . It will briefly be the largest floating array in the world, but other projects look set to overtake it before too long. A solar array at the Yamakura dam in japan will have 50,000 solar panels and generate 13.7 MW [9, 4]. The Brazilian government has plans to build a 350 MW solar array .
These projects looks set to provide a substantial amount of clean electricity for water distribution over the coming years.
- The Guardian: Cuts to subsidies for solar farms
- The Guardian: Solar panels don't harm UK food security
- Floating Solar Panels at Napa Valley’s Far Niente Winery (links to pdf)
- Wired: Yamakura Dam solar farm
- BBC news: Solar array on London reservoir.
- Thames Water
- United Utilities .
- The Guardian: London and Manchester solar projects.
- The Guardian: Yamakura Dam solar farm
Image credit: Kyocera TCL Solar LLC, rendering of the planned solar array on Yamakura Dam.
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