Around the world, many owners of lakes and reservoirs are choosing to float more than boats or ducks on their water assets; they’re developing floating solar PV.
A floating PV system comprises of a platform – upon which modules, combiner boxes and cables are placed – connected to a mooring and anchoring system. Inverter stations are usually located on shore, connected by an underground cable.
The global market in floating PV systems has grown significantly over the last few years, with an estimated 1.3 GWp of global installed capacity as of the end of 2018. What’s driving this growth?
Floating PV gets around the problems of constrained land availability, high costs associated with land acquisition and the complexity of topographies – they provide open, flat surfaces. They are also more efficient than their land-based cousins due to the increased cooling effect produced by the water and the reduced likelihood of panel shading from surrounding areas. In turn, floating systems reduce evaporation from water bodies, preserving water for uses such as drinking or irrigation.
Floating PV isn’t a new idea; it’s been tried and tested around the world – including in severe weather conditions. The first floating solar project was installed in 2007 in Aichi, Japan. The first commercial project was installed in California in 2008. Systems greater than 1MWp started to be installed after 2013, with the largest system currently installed in China at 150MWp. In 2016, Thames Water installed a 6.3MW floating solar farm on the surface of the Queen Elizabeth the Second reservoir outside London.
At WSP, we’re involved in all aspects of solar PV development, from feasibility to construction management. This means we’re well placed to understand and tackle the distinct technical, economic and environmental challenges floating systems pose for designers and developers.
These challenges mean that floating systems are approximately 18% more expensive than land-based systems, with a greater insurance price. However, generation can be expected to be 5-10% higher, due to improved performance of the module from the cooling effect of the water. Overall, with power purchase agreements in place enabling developers to secure funding and generate income, floating solar makes for an attractive investment.
For owners of water bodies, another plus point is that floating PV doesn’t require planning permission. In that sense, development is straightforward. Owners can partner with a provider who will develop, manage and maintain the floating solar farm for them. And I expect more owners of lakes and reservoirs will take advantage of this approach in the coming years. Floating solar farms could yet become a common sight in the UK.