Only a small portion of the Earth’s surface is land– a meagre 29%. The other 71% of the earth is covered by water – large bodies of oceans, seas, lakes and ponds. Imagine tapping into that unused space to harvest sustainably generated energy from resources like sunshine and wind.
Scientists today are exploring ways to amplify our sustainable energy transition , and the growth of floating solar power plants is one such innovation. Malaysia alone has over 90 significant lakes — both natural and man-made — which could potentially play host to such solar farms. In a world with growing land-use pressures, floating solar could be an innovation that unlocks a new future of renewable energy. It’s time to illuminate this solution, with ten fantastic facts about floating solar.
The first practical solar panels were developed almost sixty years ago. The United States’ Bell Laboratories unveiled the original pioneering commercial solar photovoltaic cell in 1954, with solar panels going on to power the Voyager 1 spaceship in 1958.
A floating solar plant in Chiba, Japan. Image credit: Spectrum.ieee.org.
Floating solar is a far fresher innovation. The first such installation took place in Aichi Prefecture, Japan, in 2007. This combined hydro-engineering solutions with increasingly affordable solar PV technologies. Since then the technology has begun to spread around the world.
The total installed capacity of floating solar stands at just over 1.3GW at the start of 2020 according to analysis by The Energy and Resources Institute (TERI). This is expected to more than triple to 4.6GW by 2022 . While that growth is certainly exciting, it’s still just a small share of the total 586GW total installed global solar capacity.
According to the World Bank, the levelised cost of energy (LCOE) – that is, the cost of energy produced over the lifetime of a plant – for floating solar is broadly the same as a similar capacity ground-mounted system.
the levelised cost of energy (LCOE) floating solar is broadly the same as a ground-mounted system
Given the fact that floating solar requires higher capital investment due to the more complicated nature of the supporting structure, the cost benefit of this technology will need to be calculated against various factors. This includes a country’s geographical limitations, land availability, renewable energy targets, and so on.
With this in mind, floating solar is not a replacement of traditional land-based solar installations, but a new option for renewable energy that complements existing technologies by unlocking fresh opportunities for deployment.
Unlike large-scale land installations, floating solar does not have to tackle competing pressures for land use such as agriculture to feed growing populations, or housing for citizens. It takes around 2.5 acres of land-based solar panels in a high-exposure area of sunlight to generate 1MW of electricity. Delivering solar power on an industrial scale requires huge areas of land that might otherwise be used for other key societal needs.
Rooftop solar is another growing area of solar opportunity. This technology utilises wasted rooftop space to generate electricity from solar panels. Malaysia boasts over 3.2 million landed properties , creating a huge potential opportunity for solar generation. However, each rooftop is limited in size, with around 100sqft required for just 1kW of energy.
Floating solar offers a balance between these needs. It can be deployed on a large scale without sacrificing land, turning an unused surface of water into a remarkable solar power opportunity.
The more technically challenging deployment is, the more questionable the cost benefits of floating solar becomes. With more than 400,000 square kilometres of man-made lakes globally, the theoretical potential of floating power is over 400GW.
It’s estimated that to install a floating solar power plant equivalent to the 2.4GW generating capacity of Malaysia’s Bakun Dam would require just 3% of the area of the dam’s reservoir.
While inland waters (like lakes and reservoirs) are the traditional home of floating solar, developing sea-based solutions could be a game-changer.
Maldive’s floating solar panels. Image credit: Swimsol.com
The first sea-based solar plant was deployed in the clear blue waters of the Maldives in 2014. The SolarSea Platform supplies 25 households with clean energy, saving up to 12,000 litres of diesel and reducing the cost of energy for local residents by up to 50%.
However, marine solutions are limited to shallow near-shore coastal areas currently, and represent a far greater technical and operational challenge. These challenges are also mirrored in floating wind turbines , where the deeper the sea, the higher the risk.
Japan cleverly took advantage of that head start in Aichi Prefecture, and is now a world leader in floating solar technologies. The waters of Japan are home to more than 70% of the world’s 100 largest floating solar facilities.
While a commitment to innovation is crucial to this success, Japan also benefits from favourable geographical conditions. The Honshu region alone is home to almost 40,000 inland lakes, making it fertile waters for floating solar growth. The largest facility in Japan covers 18 hectares, powers more than 5,000 homes, and saves more than 8,000 tonnes of CO2 annually.
Global renewable energy leader China is home to the largest floating solar power plant . This sprawling facility boasts over 166,000 solar panels, floating on the lake above a collapsed coal mine in Huainan city, Anhui province.
This mega-plant has a total installed capacity of 150MW and generated enough electricity in its first year to power over 21,000 homes. While Japan is a pioneering global leader, China has taken over at pace.
Asia is leading the charge on floating solar technologies. China, Japan, Korea, and Taiwan are the top four global users of floating solar power.
China is well ahead of the pack, accounting for almost three-quarters (960MW) of the total global installed capacity. Pioneer Japan comes in second with 210MW, and Korea in third with 79MW. Floating solar plants are in operation across the Southeast Asia region, with Malaysia, Indonesia, Vietnam, and others exploring this rising tide.
Singapore is also looking to leverage the potential of floating solar, creating a renewable energy opportunity that bypasses the land-use challenges this compact city state faces.
Floating solar farm in Tengeh Reservoir, Singapore. Image credit: Straits Times.com.
A major floating solar plant was announced in early 2020 , covering the equivalent size of 45 football fields across the waters of Tengeh Reservoir. Once complete, this sprawling floating power plant will generate enough energy to power 16,000 Housing Board flats. This continues a commitment to innovation which also saw one of the world’s largest offshore floating solar plants begin operation in the Straits of Johor in 2019.