Assembling and installing a floating solar farm in Colorado, United States. Photo: Flickr.com / National Renewable Energy LAb CC NY-NC.-ND
The rise of floating solar photovoltaic farms
Solar power is now the cheapest source of electricity in history. To continue its expansion many have looked to the benefits of floating solar farms.
This summer one of the largest inland floating solar photovoltaic (PV) farms was officially deployed on the Tengeh Reservoir in Singapore. It is made up of 122,000 solar panels covering 45 hectares. The 60 megawatt-peak solar PV farm is a step towards Singapore’s goal to quadruple its solar energy capabilities by 2025. The solar farm could help to reduce carbon emissions by about 32 kilotonnes annually. The project, covering an area equivalent to 45 football pitches, is long overdue as Singapore is one of the biggest carbon dioxide emitters per capita in the world.
The Asia Pacific region plays a leading role in floating solar deployment, with 87% of the world’s floating solar capacity. Currently, China has the largest number of plants installed, with a capacity of around 1.1 GW. Japan and the United Kingdom follow, but India has also recently announced a plan to develop 10 GW of floating solar plants.
Recent studies have shown the technology generates more electricity than rooftop or ground-mounted solar installations. This is due to the cooling effect of the water beneath the panels and because there is no shading impact from other buildings. This can boost how efficiently these systems generate electricity by as much as 15%.1
An interesting European example is in the Netherlands, where Europe’s largest floating, sun-tracking solar park is just four miles from central Rotterdam. The energy yield is 20 to 30% higher than with static land-based systems. The system is highly efficient, due to the fact that it continually tracks the sun, and thanks to the water-cooling effect on the solar panels. Rotterdam can get strong winds, so the panels are fitted with sensors to monitor wind forces and the height of waves, making the system stormproof. If the wind gusts at 47 to 53 mph, the island square is turned into the wind, so it blows through the rows of solar panels.2
New research has even shown that floating solar farms can also help protect lakes and reservoirs. Freshwater bodies cover less than 1% of Earth’s surface, they nurture almost 6% of its biodiversity and provide drinking water and crop irrigation that’s vital to billions of people. The surface temperature of lakes has risen by an average of 0.34°C per decade since 1985 due to climate change. The temperature increase encourages toxic algal blooms, lowers water levels and prevents water mixing between the distinct layers that naturally form in larger and deeper lakes, thereby starving the depths of oxygen. Research based on Windermere, the largest lake in England, showed that floating solar farms reduced evaporation and improved water mixing in the lake, which helps oxygenate the deeper water.3
If just 1% of the surface area of all human-made water bodies (which are easier to access and typically less ecologically sensitive than natural lakes) was covered by floating solar panels, it could generate 400 gigawatts. In Europe, 10% of man-made freshwater reservoirs has the potential to produce over 200 gigawatts if floating panels were installed.
In the past five years floating solar power has grown more than a hundredfold, reaching 2.6 gigawatts of installed capacity across 35 countries. It is important to look to this development and to enable floating solar farms to make an important contribution to the decarbonisation of the world’s energy supplies.
1 Reuters, Chen LIn, 2021, https://www.reuters.com/business/energy/singapore-unveils-one-worlds-big...
2 Barone, Jeanine. 2021. https://www.architecturaldigest.com/story/building-europes-largest-float...
3 Exley, Giles 2021. https://theconversation.com/floating-solar-farms-could-cool-down-lakes-t...