Unwrapping the global potential of floating solar

New research has found that floating solar photovoltaic (FPV) panels could supply all the electricity needs of some countries.

Researchers from Bangor and Lancaster Universities and the UK Centre for Ecology & Hydrology have looked at nearly 68,000 inland bodies of water around the world and, based on the local climate, estimated the potential electricity generation from a floating solar array.

The lakes and reservoirs they examined were carefully chosen to fullfil the certain criteria:

• No more than 10km from a population centre
• Not in a protected area
• Not likely to dry up or freeze for more than six months each year.

Their calculations were based on the assumption that solar panels would cover no more than 10% of the water’s surface up to a maximum of 30km².

Their calculations suggested that the potential annual electricity generation from floating solar on these bodies of water would be 1,302 terawatt hours, or four times the total annual electricity demand of the UK.

FPV is considered to have a number of advantages over the land-based counterpart. the cooling effect of the water makes the panels more efficient, they are easy to install as no fixed structures are required, they are easy to move and, of course, they don’t take up any land.

On the environmental side, there are positives insomuch as FPV prevents water evaporation and can control the growth of algae blooms but the team however recognise that the negative environmental impacts of floating solar is not fully understood and more research is needed in this area. 

Lead author of the paper, Dr Iestyn Woolway of Bangor University said: ‘We still don’t know exactly how floating panels might affect the ecosystem within a natural lake, in different conditions and locations. But the potential gain in energy generation from FPV is clear, so we need to put that research in place so this technology can be safely adopted. We chose 10% of a lake’s surface area as a likely safe level of deployment, but that might need to be reduced in some situations, or could be higher in others.’

The team looked at how individual countries would benefit from FPV being installed in those 68,000 lakes and reservoirs. Five countries, including Papua New Guinea, Ethiopia and Rwanda, could meet their entire electricity needs from this source of energy alone. Bolivia (87%) and Tonga (82%) would come very close.

Inevitably, those countries in parts of the world with a solar-friendly climate – Africa, the Caribbean, South America and Central Asia – will benefit the most. The team found that in these areas, most countries could meet between 40% and 70% of their annual electricity needs through FPV.

By contrast, the UK could produce just under 1% of its overall demand, although this is still enough provide for around one million homes.

Dr Woolway said: ‘Even with the criteria we set to create a realistic scenario for deployment of FPV, there are benefits across the board, mainly in lower income countries with high levels of sunshine, but also in Northern European countries as well. The criteria we chose were based on obvious exclusions, such as lakes in protected areas, but also on what might reduce the cost and risks of deployment.’

Co-author Professor Alona Armstrong of Lancaster University said: ‘Our work shows there is much potential for FPV around the world. But deployments need to be strategic, considering the consequences for energy security, nature and society, as well as Net Zero.’

The research is funded by the Natural Environment Research Council, part of UK Research and Innovation.

Photo: Giles Exley