Image: Andreas Gücklhorn (unsplash).

When people in the industry discuss large-scale solar projects in the UK several names come to mind, names such as Shotwick Solar Park, Little Crow Solar Park and Botley West amongst others, have since gained attention due to the sheer generation capacity anticipated once each have been completed.

But perhaps the most influential of them all, and for the entirety of the UK solar industry, achieved a significant milestone on its journey in November 2018. This was when Cleve Hill Solar Park, which once completed will consist of 373MW of solar and more than 150MW of battery energy storage, submitted its Development Consent Order (DCO) application to build the first solar Nationally Significant Infrastructure Project (NSIP).

It was granted development consent by the energy secretary in May 2020 and began construction in April 2023.

Gareth Phillips, partner at Pinsent Masons, told Solar Power Portal he became involved with the project off the back of working with renewable energy company SunEdison, prior to it filing for bankruptcy in April 2016.

“SunEdison had been approached by Hive Energy and for a year, the two companies ran it as a joint venture . We started pre-application work, and getting all the surveys going etc and then SunEdison went bust,” says Phillips.

“We courted quite a few investors that came to look at it, but many of them backed off because it hadn't been done before. Then along came Wirsol Energy.”

The joint venture,, between Hive Energy and Wirsol Energy, dubbed Cleve Hill Solar Park Limited, was ready to support the development process of the project. But the process of its development was to be different for both parties. Phillips stated that Hive Energy would typically develop solar projects, getting the consent and then contract an EPC like Wirsol to build the projects.

Phillips says: “Wirsol decided to take an equity stake in the project and run it with Hive as a joint venture and that's what they did.”

This links to another key question when discussing the Cleve Hill project – why did it take so long to get from origination to the submission of a DCO. This is down to one specific reason Phillips believes.

“The golden question for Cleve Hill was always why it took a long time to get from origination to get a consent application in and then consent,” Phillips says. “That's less to do with the consent process and to do with SunEdison going bankrupt and the time it took to find another investor.”

But despite the project being in somewhat of a ‘limbo’, the payoff for developing such a project was monumental for the UK solar industry. Phillips indicated that at the time, he thought that Cleve Hill “might end up being a one-of-a-kind project”. But when the industry caught wind of the project, suddenly large-scale solar projects started to gain traction.

“By the time we got consent in March 2020, there were probably about 10 viable projects. It was starting to be a case of maybe 500MW around that average size,” Phillips said. “And then since then, it's just gone barmy, mostly because of the difficulty in securing grid connections. Developers couldn't get distribution network connections, so they got transmission  system connections and increase the size of the projects to meet the available connection capacity.

“There was also a move away from single sites, like Cleve Hill was a single site. Many of the projects we see coming forward now are multiple sites all connected together. That approach has unlocked a lot of more projects.”

As stated by Phillips, multiple site solar farms are now becoming a staple of the UK solar industry. By combining several solar sites, projects are more likely to receive planning consent and can also increase the generation capacity of the overall project.

A perfect example in utilising this project development method can be observed in Oxfordshire’s Botley West, an 840MW multi-site solar project which consists of three separate sites. These will be located to the west of Oxford within the districts of West Oxfordshire, Cherwell and the Vale of White Horse.

Solar Power Portal spoke with Photovolt Development Partners’ (PVDP) Mark Owen-Lloyd, project lead for Botley West, in January to find out more about the public consultation process, issues surrounding public perception of solar projects and how NSIP projects could be key in unlocking the UK’s budding renewable sector.

The Botley West project is a perfect example of the long-term effects of the successful DCO process for Cleve Hill. And as Phillips states, the DCO processes can provide benefits for developers despite the costs associated.

“That's the neat thing about the DCO process. You put all the powers you need into one consent and and have relative certainty of the consent being granted, provided the application is prepared well. Even though it's a more expensive route, that's what developers are seeing the attractiveness to,” Phillips says. “They think that, if we do it this way, we'll have fewer problems convincing investors and financers that we've got all that we need to build out the project.

“It's phenomenal how during the course of Cleve Hill, when it was going through the application process, how many projects suddenly started popping up. A lot of people decided to wait until the consent was granted because at that point, we didn't have a national policy statement with solar in it.”

In this regard, Cleve Hill has become a crucial development for the solar industry, and when questioned as to whether the project put large-scale solar developments on the map in the UK, Phillips is assertive in his response.

“Oh, without a doubt no. No one had seen anything of that scale,” he says. “Suddenly, someone comes along with a whopping 350MW proposal, but also, it had co-located battery, and the battery, at the time was the largest seen too.”

Despite the positives, the project also had its critics.

Phillips says: “A lot of people thought it [the project] wouldn't fly. They thought the objections would be massive and there were a lot of people questioning whether it was the right way to take solar forward. Can you bank it? Can you take a project that size to market? Will you find someone who's going to buy it?”

Despite this, the scale of the project does not compare with some developments abroad. In the Middle East, Europe, in the Americas and in Asia, it is not uncommon to see solar projects with gigawatts in generation capacity. This analysis in particular humours Phillips.

“It's quite funny, because in the context of the UK being a small island with sub 50MW projects, people were thinking this was a huge. But if you look over onto the continent in Europe, and then go to China and in the US, you're talking about 1GW and 2GW projects. So actually, when you saw it from a global perspective, a 350MW solar park with the type of consent that it has, it is very investable, bankable etc.

“It definitely put large-scale solar on the map.”

It’s hard to argue with Phillips' assessment that Cleve Hill was indeed a key project in the development of large-scale solar projects across the UK. Since then, Solar Media's Market Research team has disclosed that there are “65 solar projects currently in planning larger than 350MW, including four 1GW sites”. But what other factors helped increase the likelihood of the project receiving a DCO?

“We included some flexibility that if an end user for the battery didn't come forward, we could substitute more solar panels in the place of the battery. If they wanted to, they could just do one big solar project,” Phillips says.

“That actually helped with investors and buyers, because a lot of the buyers that came along didn't know how to price the battery because there wasn't an obvious end user for it. They priced it entirely on solar, they just offered a price that was for a 350MW solar project.

“Some people only wanted to build it out that way, but when Quinbrook bought in, they planned on building it out as per the consent. They are going to be building the battery and the solar – I think the solar park is now about 373MW because of the improvement in technology and detailed design.”

With the successes of Cleve Hill and the DCO process now coming to fruition via the start of construction of the project, it is important to support other NSIPs and proposed large-scale projects to ensure the UK is able to attain its net zero targets.

“As we move forward over the next few years, undoubtedly, sites that have been discounted by some developers are being brought forward by others,” Phillips predicts.

“I think the main tip for developers is, as ever, the quality of the site. Is it low grade agricultural land? Is it a good location in terms of ecological designations, important landscapes and avoiding areas of outstanding natural beauty? How close is it to villages? They've got to think about all these things, and not just think that this consent process will just fly through. We're about to get very strong policy in the national policy statements for energy and that's great, but it doesn't mean 'solar at any cost'. The quality of the site is imperative.”

Solar Media's Market Research Team has been exploring large-scale solar farms via its 'UK Large-Scale Solar Farms: The Post-Subsidy Prospect List'. You can find out more about the list here.