Floating Solar Farms Power Up To Boost Sustainability

Floating solar systems are providing power, clean water as well as a more sustainable and environmentally friendly future.
Published: Fri 11 Mar 2016

The world’s largest floating solar farm, located on the outskirts of London, UK, is about to be powered up.   

The 23,000 solar panels, floating on the Queen Elizabeth II reservoir at Walton-on-Thames, will generate sufficient electricity (6.3MW-enough to power 1,800 homes) to power the utility’s local water treatment plants. In addition, the energy will help get clean drinking water to approximately 10 million people in greater London and the southeast of England.

The £6 million project, launched five years ago, will reach completion by March this year by developer Lightsource Renewable Energy.

Floating panels, covering only about 6% of the reservoir, will have no impact on the ecosystem, according to the project management team.

Eighteen metres deep, the reservoir provides water for Londoners in a constantly churning stream. Although most of the population growth in London tends to be towards the east, most of the water still comes from reservoirs to the west of the city.

A similar floating solar farm with approximately half the capacity of the Thames Water project is being built by water company United Utilities on Godley, a reservoir in Hyde, Greater Manchester. The farm’s 12,000 solar panels will generate 2,700MWh of electricity each year. The £3.5 million project will cover 45,500m2 of the reservoir.

The project contributes a large portion of United Utilities’ aim to generate 35% of their power requirements by 2020.

The floating solar array provides the water treatment works with approximately 33% of its energy requirements.

United says the Godley installation will be far larger than the only other floating solar site in the UK, an 800-panel pilot project in Berkshire. [Floating Solar Makes Energy On The Water] It appears the Godley system will also be the largest of its type in Europe.

The solar array will be second biggest in the world after a scheme in Japan according to United Utilities.

While floating solar projects reservoirs may seem like a great idea, future projects in the UK may hang in the balance no thanks to the UK government slashing its subsidies.  Thankfully the Queen Elizabeth II project will not be affected.

Global interest in floating solar farms

Further abroad, construction of an even bigger farm - at 13.7MW more than twice the Queen Elizabeth II farm - is underway on a reservoir in land-scarce Japan. The completion date is set for 2018.

Brazil’s energy minister has also announced plans for a massive 350MW floating solar farm at the Balbina hydroelectric plant in the Amazon.

The US has also jumped on the floating solar bandwagon. For instance, Far Niente winery in California’s Napa County, has a 477kW land and floating solar system which has been running successfully for the last few years.  

Australia has also joined the floating solar market. Last year, a floating 4MW solar farm valued at US$9.5 million was developed at a wastewater treatment facility in Jamestown in South Australia’s mid-north region. The farm generates about 57% more power than land-based systems, and produces enough to meet the electricity requirements of the entire wastewater treatment facility.The power station distributes the surplus power to the town’s locals.

Why floating solar farms?

Floating solar power stations have a few advantages over land-based systems.

Reservoirs, especially, are a great place to float solar panels, because shading the water helps to prevent evaporation, saving water, and increasing efficiency – the same reason India has been installing them over its irrigation canals.

The water keeps the solar panels cool, boosting conversion efficiency (because panels are less efficient at high temperatures). The shading also has benefits for water quality and biochemical oxygen demand and it inhibits blue green algae growth. Disruption by wildlife is minimal since reservoirs are man-made and carefully controlled.

The floating solar system has potential to help insulate water utilities from escalating power prices, enabling them to keep water prices down.

Floating solar has also been of special interest in countries where land may be at a premium. In fact, Japan has several of these floating solar farms due to a shortage of agricultural land.

Increasing energy costs, the need to reduce carbon footprints and a shortage of land is bound to boost the growth of floating solar.