PARLIAMENTARY DEBATE
Floating Solar Panels - 26 June 2025 (Commons/Commons Chamber)

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.

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?

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.

My hon. and gallant Friend is talking about the use of prime agricultural land, and food security is part of national security, as is energy security and, indeed, water security. However, there is a huge trend of prime agricultural land being devoted to solar plants, including in my constituency of Epping Forest, where a new plan is about to go in for a 237-acre plot between Thornwood and Epping Upland. He is articulating alternatives for the placing of solar panels, and there are plenty of such places up and down the land—brownfield sites, reservoirs, railway sidings, rooftops of agricultural buildings—so does he agree that we must protect prime farmland and the green belt, and make sure that solar panels go in the right places?

I completely agree with my hon. Friend. I hope we are going to give hope across the House and therefore across the country that this alternative solution to putting solar panels on grade A agricultural land is, to a certain extent, an answer to a maiden’s prayers. Not only does floating solar remove the opportunity costs of putting it on agricultural land, but one of its beauties is that it is twice as efficient as a land-based system. Land-based systems warm up because they are on the land, and as they warm up they become less efficient, whereas floating solar panels, because of the evaporative effect on the underside, remain automatically cool and 100% efficient throughout a sunny day.

As the hon. Member for Strangford (Jim Shannon) is not here, unusually, perhaps I can fill in for him. We have already heard from one of my Essex colleagues, my hon. Friend the Member for Epping Forest (Dr Hudson), about the controversy in Essex over a number of solar farm developments on land. Before the 2010 boundary changes, I had a very large reservoir in my constituency at West Hanningfield, which would be ideal for the technology my hon. and gallant Friend is suggesting. Does he not believe that many hundreds of other reservoirs across the country would be so suited?

I do, indeed. I was not 100% sure which Minister would respond to this debate, so I have had only the briefest of moments to look at the lake in Burgess park in the Minister’s Peckham constituency to see whether that may be suitable for floating solar.

We have talked about the opportunity costs and about doubling efficiency. I am sure hon. Members will have worked this out, but the 2,000 acres of reservoir in my Spelthorne constituency are raised, which means no one can see the top of them unless they are flying off to Torremolinos or landing from Dubai. Therefore, there would be none of the visual vandalism that people object to so much, and the carpeting of our beautiful country in solar panels would go away too.

I am grateful to my hon. and gallant Friend for joining this merry band of evangelists for floating solar, and for seeking to get in on the ground floor with the inclusion of the reservoir in his constituency. Within minutes, he is immediately seeing the opportunity, and I congratulate him on that.

I am really happy to join this debate, which is not only amusing, but very educational. For me, it is a matter of great concern for this country to conserve the water supply we have. Does the hon. Member therefore agree with me that floating solar stops the evaporation of water because it avoids direct sunlight hitting the water, and that it also conserves water?

The hon. Member, with whom I serve on the Defence Committee, makes a very important point about future-proofing the United Kingdom’s water supply from increased temperatures. In Australia, I understand that reservoirs are being covered at great expense to reduce evaporation. He might know that where floating solar panels exist, they reduce evaporation by 70. In the case of the Queen Elizabeth II reservoir, that is 100 tonnes of water a day. It is absolutely extraordinary.

I know Members are thinking, “Well, Lincoln, it couldn’t get any better,” but I have to tell the House that there are still some further benefits. [Hon. Members: “More!”] Where reservoirs are owned by water companies and the water companies want to use the electricity themselves, there is no requirement for planning permission. When we consider the turmoil that land-based systems have to go through over many, many years, and the paroxysms the nation puts itself through before it puts in a land-based system, we should note that floating solar can be deployed within a few weeks.

This is another issue where the Conservatives can perhaps give more information to those on the Government Benches. We have real issues in many parts of rural Britain with the energy infrastructure that has to go alongside solar farms—for example, the massive mega-pylons in East Anglia. If the energy can be used onsite or if there is existing energy infrastructure, as there often is around reservoirs due to hydro and other factors, that is another great reason why floating solar is a solution that everyone can get on board with.

My hon. Friend makes a fantastic point. The Queen Mary reservoir in my constituency has a plug-in point to the national grid at one end of it. The ability to minimise the disruption that is caused by placing solar farms away from where the power is needed is certainly a consideration that plays into this.

Hon. Members will think, “Well, that must be his list complete. Those must be all the benefits of floating solar, because there can’t be any more.” But I say to the House that one of the most astonishing things about floating solar is that it improves the water quality underneath, as it is denuded of light and heat. There are things that grow in the water which the water companies subsequently have to filter out to make it tap-ready for us and our constituents. The water companies have to use fewer filtrants where the surface has been covered by floating solar. We have covered the evaporative effect, so I think I have made the case for floating solar.

My hon. Friend makes a strong point about being able to use floating solar to obviate the need for development on green-belt land in other parts of the country. Is he aware that a development has been proposed by Bloor Homes at Dollymans Farm in my constituency for up to 1,300 houses, which is a major issue in the ongoing by-election in Wickford Park? Does he agree that to prevent the housing at Dollymans Farm, people should vote for the excellent Conservative candidate, Lewis Hooper, before the polls close tonight?

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.

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.

On Tuesday, I visited the Queen Elizabeth II reservoir, which is a closed site owned by Thames Water. I am not aware that there were any fish there, but there was certainly bird life. It is important to make the point that the general planning norm and all the modelling have been based on covering only 15% of these reservoirs, in order to leave sufficient space for leisure use, including fishing, no doubt, and for bird life. The birds I saw on the Queen Elizabeth II on Tuesday were warming themselves very happily on the floating solar panels, because, of course, by being on the panels, they are predator free, as nothing can attack them there.

“How big could this be?”, I hear the House roar.

How big could this be?

I thank my hon. Friend for that.

The installed base of every single solar panel in the United Kingdom is producing 17 GW. If we were to cover 15% of man-made reservoirs in this country, we would double the national capacity, adding a further 16 GW without touching an inch of agricultural land. That is absolutely extraordinary. In so doing, we would create 80,000 jobs in the construction phase and 8,000 jobs in the maintenance phase.

My plea to the Minister—who I know is putting the finishing touches to the Government’s solar road map—is that floating solar should play a much greater part in the final road map than it did in the first draft. I am grateful to my right hon. and hon. Friends for their support; I hope this debate has been educational and informative, and that they are now fully signed up to the floating solar brethren and sisterhood, which will go forth from this place and evangelise for the good cause.

I thank the hon. and gallant Member for Spelthorne (Lincoln Jopp) for securing a debate on this important issue and for prosecuting his case for floating solar with such flourish. I also wish to put on the record that the Minister for Energy, my hon. Friend the Member for Rutherglen (Michael Shanks), was desperate to be here and is very sorry that he cannot be, but I am glad that I am able to stand here in his place. I am also glad that the hon. and gallant Gentleman was able to make his speech today, as I know he was not able to intervene in the recent solar debate.

Let me start by saying that I absolutely agree. The Government are very clear that, like the hon. and gallant Gentleman, we believe there is an exciting role for floating solar. It is a new technology, but one that we think has huge potential. Developers around the world started to come forward with utility-scale proposals in the past decade, and several large projects have been constructed in recent years, including installations with the capacity to generate hundreds of megawatts of electricity, which have mainly been in China.

The hon. and gallant Gentleman has very effectively set out the upsides of floating solar, so I will not reiterate them. However, I want to put on the record that we agree, and that we recognise many of those upsides.

I will say a little about the state of floating solar in the UK today. There has been some deployment of floating solar in the UK. Lightsource led a project on the Queen Elizabeth II reservoir, which is just outside the hon. Gentleman’s constituency, as he mentioned. The project uses 24,000 solar panels to generate around 20% of the site’s electricity needs. It was, at the time of construction, Europe’s largest floating solar installation. There are now other, smaller projects across the country, but the scale is still nascent and very limited.

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.

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.

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.

I just point out to the Minister that she could save herself a vast amount of political pain, because, apart from a few swans that I saw, a couple of seagulls and one man from the Royal Society for the Protection of Birds, there ain’t many people who are going to complain about putting floating solar on raised reservoirs.

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.

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.

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.

I wonder whether the taskforce has engaged with the company that runs the Queen Elizabeth solar farm; it is called Bluefield—very clever name; very clever company. It wrote to the Secretary of State earlier in the year, some four months ago, but is yet to receive a reply. I would be grateful to know whether the Department is engaging with Bluefield and whether I could nudge the Secretary of State to reply to its letter?

I thank the hon. and gallant Gentleman for that; his nudge has been taken, and I will pass that on to the Minister for Energy. As a Department, we are trying to engage extensively with industry on how we will take forward the complex and difficult challenges as we try to deliver our clean power mission. If companies and organisations can lend their insights and knowledge to help us develop better policy, we are always in the market for that, so I will pass on the nudge.

We are finishing the final touches to the solar road map, and it is due to be published very soon. While I will not disclose the detail of it, I assure hon. Members that the question of floating solar will be addressed within it. We recognise that floating solar is an exciting area, and we think it has huge potential for deployment in the UK. We are seeing the technology being deployed more broadly in other countries, and we want to be part of that. The hon. and gallant Gentleman has talked about the benefits for the grid, water quality, consumers of electricity and, ultimately, climate change.

There is much to like about floating solar. The challenge for us is to work with industry to ensure that we can unlock its potential. That means reducing the cost, ensuring that it is cost-effective, and ensuring that we can deploy the technology. The one commitment I will make on behalf of the Government is that we will always engage with industry as we do this work. We want the innovation, insight and experience of the brightest and the best as we try to build up our clean power sector, so we will work with industry to unlock the huge potential that we believe is there.

Question put and agreed to.