On 26 October 2015, United Utilities ("UU") revealed its plans to invest £3.5 million in what will be Europe's largest floating solar power development. It plans to install 12,000 solar panels on the surface of Godley Reservoir in Greater Manchester and expects the 3MW project to meet a third of the energy needed for its nearby water treatment works.
Floating solar technology was introduced to the UK last year by entrepreneur Mark Bennett, whose pilot project on a 60 million litre irrigation reservoir at Sheeplands Farm in Berkshire was completed in September 2014. The primary use of the installation is to power the pump that sends water from the reservoir to irrigate the farm.
Mark Bennett has said that although his target market is "functional reservoirs" typically owned by utility companies, the technology represents a "revolutionary new alternative for owners of large used and unused bodies of water… wanting to generate both renewable energy and sustainable income."
The Sheeplands project of 800 panels and 200kw capacity spanned roughly an acre and took only a week to install. The panels are mounted on plastic floats forming a giant pontoon.
This is not the only way they can be mounted on water; UU have also applied for planning permission to construct panels on Langthwaite Reservoir, Scotforth, where the panels will be connected to a supporting frame anchored to the bed of the lake and suspended half a metre from the surface of the water.
The Sheeplands Farm development was installed at a cost of £250,000. It will earn £20,500 per annum in subsidies and save about £24,000 per annum in power it would otherwise have to buy from the grid. The project could therefore pay for itself within six years and should deliver profits of more than £620,000 over 20 years. There are a number of other benefits to using water-mounted solar farms:
- no farming activities need be sacrificed to make space for them
- they deliver higher levels of conversion efficiency than land-based farms, because of the cooling effect of the water
- they increase the lifecycle of a reservoir by reducing water evaporation and the natural erosion caused by wave movement. They also slow the growth of algae
- they have a low impact on the water quality and surrounding environment, are quick and easy to install and made of recyclable materials.
Projects such as these tend to be more suited to man-made non-tidal reservoirs than they are to natural lakes, where there may be concerns about protecting scenery and the delicate natural ecosystem of the lake. In addition to this, where bodies of water are not entirely in the ownership of one landowner, other riparian owners will have common law rights over a lake and may only agree to the interference with these rights for a fee. The most straightforward scenario for incorporating floating solar into a farm or estate, then will be where the body of water is wholly owned and has a purely functional, rather than an aesthetic, purpose.