Floating Solar Panels

John Cooper Excerpts

Thursday 26th June 2025 Commons Chamber

[Lincoln Jopp (Spelthorne) (Con)]

I am delighted to see the House so full for this Adjournment debate. I want hon. Members who are staying to remember who was here. Indeed, people in the Public Gallery might wish to make a note in their diary, too, because I hope that I will in some way blow the House’s mind with what I am about to say and sow a seed that will grow into something fantastic. What we are here to discuss is floating solar.

Members will know that I am the Member of Parliament for Spelthorne. I feel obliged to remind the House on regular occasions that Spelthorne is not in Lancashire or in Lincolnshire. It is everything south of Heathrow until one gets to the River Thames. Hon. Members from around the House know my constituency well, because it is what they see when they take off from or land at Heathrow airport.

I was selected as the candidate for Spelthorne four days into the general election campaign. Having spent 25 years in the Army, obviously I love a map. There is a very good saying, “If you don’t understand what is going on, get a bigger map.” When I looked at a map of Spelthorne, I was struck by these four massive blocks of blue, so I looked into them. They are four raised reservoirs, which hold half of London’s drinking water. Being a practical person, I first thought to myself, “Well, there are not many votes there!” Secondly, I thought, “I cannot really build any houses there.” Spelthorne is 67% green belt and water, and a large chunk of the rest of it is floodplain, so it is difficult to know what we might do to meet our housing targets; people get crammed into the small islands where development can happen.

I was determined, though, to find some way to utilise the 2,000 acres of raised reservoir in my Spelthorne constituency. I looked into it a little further, and came upon the concept of floating solar. This is a terribly simple concept: simply take solar panels, attach them to plastic floats, anchor those floats to the bottom of the reservoir, and string some wires to take an alternating current from the floating solar panels. The clever bits, in terms of intellectual property, are the anchors—because, as I am sure hon. Members know, the depth of reservoirs tends to vary by about 1 metre from time to time. Equally, reservoirs are drained and reassessed on a rolling cycle of about 20 years.

[John Cooper (Dumfries and Galloway) (Con)]

I thank my hon. and gallant Friend for allowing me to intervene. We are told that there is nothing new under the sun, but he is describing something that ticks both boxes—it is quite remarkable. I learned much about reservoirs from playing by the side of the scenic Penwhirn reservoir, outside by home town of Stranraer. I also learned about them in geography classes at Stranraer academy, and it strikes me that one of the reasons that reservoir levels rise and fall is to do with evaporation, and water is obviously a precious resource. Does covering reservoirs help to combat evaporation?

[Lincoln Jopp]

My hon. Friend pre-empts one of the many benefits of floating solar that I will highlight to the House. He remembers his physics highers well, because the placing of floating solar reduces evaporation from the body that is covered by 70%. Given that the vast majority of the water in our reservoirs is lost through evaporation every year, we will save a great deal more water if the Government decide to pursue this technology at a grand scale.

Part of my coming here today is to speak to two large constituencies within this House. There are 543 constituencies that contain reservoirs or man-made water sources. Similarly, countless Members from across the House have very difficult decisions to make about putting solar farms on good agricultural land. Essentially, what has happened is that the whole discussion in this area has become a zero-sum game. It is a battle between food security and energy security, and there has seemed to be no way of unpicking that—until now.

Globally, floating solar has been put to practical application at large scale in China, India and Vietnam. The UK was formerly a leader in this space, because on the Queen Elizabeth II reservoir in 2016, a grand technology demonstrator was put on and plugged in, and it has been banging out 6.3 MW into Thames Water’s water treatment facility ever since. That is enough to power 2,000 homes. Given that floating solar covers less than 10% of that reservoir, I am sure that hon. Members can see the vast potential.

I want to talk about some of the benefits of floating solar, because they are legion. First, as hon. Members will have worked out already, there is the removal of the opportunity cost of putting floating solar panels on grade A agricultural land. If we do not have to put them all over Lincolnshire and we can put them on reservoirs, that land can be used for growing food.

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[Lincoln Jopp]

We have gone from Cooper to Hooper! I am delighted to follow my right hon. and gallant Friend’s endorsement, and wish everyone there the opportunity to get to the polls today to exercise their democratic right.

[John Cooper]

I am very grateful to my hon. and gallant Friend for giving way a second time. I do wonder if I may have stumbled across another advantage to floating solar, which may not have occurred to him. If water quality is improved, will that not help the fish? Clatteringshaws loch reservoir in my constituency has some of the best pike fishing in the country. I wonder if the fish might benefit from having a roof over their heads.

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[Miatta Fahnbulleh]

I thank the hon. Gentleman for his intervention. There are many schemes and huge opportunities, and the Government are working with industry to think about what the potential is across the country. New proposals are coming forward, and we are trying to engage with them.

Although we see that there is huge potential, it is also important to put that in the context of some of the challenges we face as we try to grow floating solar. We are trying to do our part to work with industry, so we want to ensure that we deal with some of the obstacles and barriers to the schemes that are coming forward—for example, planning or investment certainty. Floating solar projects can apply to the Government’s flagship contracts for difference scheme, and they do.

I know that one of the arguments in favour of floating solar, which the hon. and gallant Gentleman put forward, and which was reiterated by other hon. Members, is that it will reduce the amount of land that we need to use. Arguments have been made about agricultural land and constraining the amount of ground-mounted solar panels on them. I gently say, however, that if we look at the statistics, we see that only 0.1% of land in the UK is covered by ground-mounted solar at the moment—a minuscule amount. Even with the expansion that we are actively trying to encourage, we are still talking about a fraction of UK land that will only ever be used for ground-mounted solar, so it is important to put that in context.

[John Cooper]

The Minister is right to point to the figures now, but this is a growing problem. One of the difficulties with the land that goes under solar panels is that it tends to be south-facing land, which is prime agricultural land. That is where the crops would normally go, so this is a growing problem.

[Miatta Fahnbulleh]

I recognise that point, but even with the expansion, we are still talking about only a fraction of land. Inevitably, regional and local government will make a judgment about the land that we protect. Everyone recognises that we must have prime agricultural land, because we need it, so we are making decisions, and local government will also be making decisions in that context.

[Miatta Fahnbulleh]

I am always in the market for less pain. Let me say a little bit about some of the constraints. Eligible bids have been submitted to our contracts for difference schemes, but unfortunately none has yet been successful. That is because the cost of floating solar is about 10% to 15% higher than those of ground-mounted projects, and the reason for that is the cost of the floating structures on which the panel sits. And we hear from the sector that these can account for nearly half of the cost of the project. Moreover, floating solar requires expensive underwater cables, which costs more than land-based systems. Therefore, although we are very keen to encourage this technology and to encourage the sector to grow, there is more that needs to be done in order to make them cost effective. From a Government perspective, it is critical that every scheme and every project that we support is cost-effective, so that, in the end, taxpayers are not footing the bill for technology that is too expensive.

[John Cooper]

I thank the Minister for allowing me to intervene again. She is making a powerful argument for looking again at the CfD scheme, which is notoriously complicated and very difficult. I think we need a two-pronged approach—we need some changes to CfD, but obviously technology associated with solar is moving on all the time, so perhaps the two could come together.

[Miatta Fahnbulleh]

We will always keep this area under review. We recognise the potential of the technology, and we will continue to work with industry to bring down costs. As the hon. Member says, there are reservoirs and waterways where there are potential problems, but there is also the potential for it to be painless. If we can help to unlock the technology, there will absolutely be appetite from the Government for this. We are trying to invest in research and development in this area, and we are putting in Government support and investment to unlock that.

Finally, the hon. and gallant Gentleman mentioned the solar taskforce. We are working at pace to deliver the taskforce’s recommendations. The taskforce has effectively brought together industry and Government to discuss the actions needed to scale up solar deployment, in line with our 2030 clean power mission. It has identified the need for a road map to address the specific barriers to floating solar and other innovative technologies, and a sub-group has been convened to focus on this specific topic.