Floating Solar

By on Apr 14, 2017 in Technology

Floatovoltaics is the name given to the floating solar plants that have started to pop up all over the globe—Japan, the UK, Brazil, the U.S. and Australia. This type of system is relatively new, but seems to gain popularity. It’s easy to understand why, the floatovoltaics preserve land, while minimizing the aesthetic impact.

Kyocera TCL Solar LLC is one of the pioneers of the technology; they state that the floating system is not only typhoon-proof (due to their sturdy, high-density polyethylene and array design), but also superior to their land-based counterparts because of the cooling effect of the water, which enables them to work more efficiently. Kyocera’s word is to be listened to as they are the developers behind the largest floating solar power plant in the world—in a joint venture with Century Tokyo Leasing Corp.

In 2016, the company started developing a 13.7-megawatt floating solar power plant on the Yamakura Dam reservoir, managed by the Public Enterprises Agency of Chiba Prefecture in Japan for industrial water services. The system will consist of approximately 51,000 Kyocera modules installed over a fresh water surface area of almost 2 million square feet. The project is expected to generate an estimated 16,170-megawatt-hours per year, enough to power almost 5,000 typical households, while offsetting about 8,170 tons of carbon dioxide emissions annually. The planned launch date for the solar plant on the Yamakura Dam is spring of 2018.

Japan was somewhat forced to find new surfaces on which to install photovoltaic panels mostly due to the decrease in tracts of land suitable for utility-scale solar power plants. Other countries and regions view solar power as the solution to the drought that’s been drying up their hydroelectric plans.

In 2015, Brazil announced that it will build an overwhelming 350-megawatt plant close to the existing Balbina hydroelectric power station on Amazon’s Uatumã River. Brazil has a good track record on renewables, sporting a mostly hydro-powered supply accounting for more than 85 percent of the domestically produced electricity used in the nation. Yet, the popular 250-megawatt Balbina hydroelectric plant has created plenty of controversy, amid claims that the methane released from the massive reservoir make it more greenhouse-gas intensive than most coal plants. The floating solar could help address this problem as it has been demonstrated to reduce water evaporation and restrict the growth of methane-producing algae.

In Jamestown, South Australia there’s a floating solar system that’s said to generate 57 percent more energy that rooftop panels. The plant floats on a wastewater facility and is the first of a larger system that will cover five basins. The array is made up of 112 solar panels that move with the sun, enabling it to soak up more sunlight and generate more energy, for more hours during the day. Moreover, Infratech Industries, the company behind the project, deploys a process called “concentration” through mirrors attached to each solar panel. These increase the amount of light hitting the panels, doubling the energy it creates compared to rooftop solar.

“We have been looking at the data that comes from a system at the site,” said Professor David Lewis, director of Flinders University’s Centre for NanoScale Science and Technology. “That’s how I am comfortable saying that we’ve got about twice the power output for the light intensity that was hitting the panels.” Flinders University is not an investor in the solar array project, but it is involved actively in the technical support role it committed to, assisting with material selection, as well as with assemblage to ensure maximum power efficiency.

In case you’re thinking that electricity and water are not the best of friends, you’re right. However, Infratech Director Felicia Whiting has a solution: “Unlike lithium-ion batteries, which are not safe for operation in and around water bodies due to the level of environmental sensitivity – the energy storage system we are funding and developing with Flinders University uses a nano particulate,” Whiting says. “We use metals that are not harmful to the water environment.”

The UK has Europe’s largest floating solar plant, a 6.3-megawatt array consisting of 23,000 solar panels on the Queen Elizabeth II reservoir at Walton-on-Thames, a suburb of London near Heathrow Airport. The floating solar plant consists of 23,000 photovoltaic panels and covers around a tenth of the reservoir, roughly the equivalent of eight soccer stadiums. The farm took about $8 million to build, and powers about 1,800 homes annually.

The largest floating solar project in the U.S. is the 12.5-megawatt facility in Sonoma County, making it second in size to the Yamakura Dam project. California’s ongoing drought has left millions of acres of farmland arid; this made the water conservation value of a floating solar farm more appealing. Sonoma County encompasses well over a thousand irrigation storage ponds, located close to existing infrastructure and distribution lines.

“Sonoma County boasts some of the most beautiful rolling hills, and people don’t want to see them covered by solar panels,” said Rebecca Simonson, a senior power analyst for the renewable energy developer, which has signed purchasing agreements for floating solar arrays to be built on six treated water ponds in the county—two in northwest Santa Rosa and four in the Sonoma Valley. The solar panels, she said, would not be visible from the road.

Upon completion, the system is expected to supply enough power for 3,000 homes. The Water Agency has identified additional potential sites for floating solar at local wineries and is planning to assist local vintners in developing smaller scale projects.