Lincolnshire is being asked to judge each scheme separately while the combined cost runs into billions
By Shane Oxer | 24th September 2026
The case for a national impact assessment begins with a simple question. What will the current wave of large solar applications cost when they are considered together rather than one at a time?
Eight named Lincolnshire schemes account for about 4,100 megawatts of proposed solar capacity. Applying the Government’s central cost benchmark for large solar projects gives an estimated construction cost of £2.702 billion.
That figure covers the solar projects themselves. It does not include the full battery build, wider transmission upgrades or financing costs. It is not a developer budget, but it is the clearest consistent benchmark available for comparing the applications.
Seven of the eight schemes have development consent. Fosse Green remained in the Development Consent Order process at the date of this article. Consent does not guarantee that a project will be financed, built or connected, but these are no longer small or speculative proposals on the edge of the planning system.
The applications and the £2.7 billion calculation
In October 2025, the Department for Energy Security and Net Zero published research by Arup on large solar projects above 5 MW. The 2023-price benchmarks were £526 per kilowatt at the low end, £659 per kilowatt in the central case and £788 per kilowatt at the high end.
Applying the central benchmark to the published capacity of each Lincolnshire application produces the following estimates.
• Springwell, 800 MW: £527.2 million
• Fosse Green, 320 MW: £210.9 million
• Beacon Fen, 400 MW: £263.6 million
• Heckington Fen, 500 MW: £329.5 million
• Gate Burton, 500 MW: £329.5 million
• Cottam, 600 MW: £395.4 million
• West Burton, 480 MW: £316.3 million
• Tillbridge, 500 MW: £329.5 million
The total is 4,100 MW and £2.702 billion in the central case. The same calculation gives a range of £2.157 billion to £3.231 billion using the Government’s low and high benchmarks.
The method is deliberately simple and open to scrutiny. It does not claim that developers have signed £2.702 billion of contracts. Individual projects may cost more or less. The benchmark is expressed in 2023 prices, and the calculation excludes batteries, wider grid works and the cost of finance.
Those exclusions matter because £2.702 billion is the starting figure, not the final sum that the projects and electricity system would have to recover.
The money already owed
The latest available accounts show that development is already being funded through project companies. Across seven companies with comparable disclosures, at least £65.745 million was owed to group companies, shareholders or related parties.
• Springwell Energyfarm Limited: £10.927 million shareholder loan, with £616,000 of capitalised interest
• Gate Burton Energy Park Limited: £24.748 million shareholder loan plus a £613,000 current group balance, with £689,000 capitalised
• Fosse Green Energy Limited: £3.228 million owed to group companies and £126,287 of interest expense
• Ecotricity Heck Fen Solar Limited: £993,000 owed to its group
• Cottam Solar Project Limited: £7.310 million owed to related parties
• West Burton Solar Project Limited: £6.762 million owed to its group
• Tillbridge Solar Limited: £11.164 million owed to its group and £533,369 of interest expense
Beacon Fen disclosed no comparable balance and reported £500 of turnover.
Four of the companies identified a combined £1.965 million of interest expense or capitalised borrowing cost across different accounting periods.
These figures need to be described accurately. The £65.745 million is not all external bank debt. It includes shareholder loans, group loans and some related-party balances. The accounts also cover different periods, and not every balance is proven to bear interest. That is why the figure is described as money owed rather than bank borrowing.
It still matters. It shows that significant costs are accumulating before the main construction programme is complete and, in several cases, before the companies have meaningful operating revenue.
What borrowing could add
The companies have not published final construction finance packages, so nobody outside the projects can state their eventual borrowing, interest rates or repayment schedules as fact.
We can, however, show what a conventional financing assumption would mean.
If 70 per cent of the £2.702 billion central estimate were financed with debt, the amount borrowed would be about £1.891 billion. If that debt were repaid over 20 years at 6 per cent, the annual payment would be about £164.9 million. Total interest over the period would be about £1.407 billion, making principal and interest approximately £3.298 billion.
This is an illustration, not a forecast or a claim about the projects’ agreed loans. Actual projects may use different debt levels, rates, drawdown dates, refinancing arrangements and repayment profiles. Equity investors also expect a return, which is separate from loan interest.
The calculation shows why the cost of building a project and the amount it must ultimately recover are different. Even before batteries and wider grid works are added, financing can change the scale of the bill substantially.
The grid bill is not included
Several of the applications depend on major transmission work. National Grid is proposing a new 400 kV substation near Navenby, including new feeder bays, circuit turn-ins and pylons. NESO’s works report also lists 17 reinforcement entries behind Fosse Green’s registered 240 MW export connection.
Those entries extend far beyond the project boundary. They include work around Navenby, the Lincolnshire coast and the wider eastern transmission system.
It would be wrong to charge every pound of those shared upgrades to the eight solar schemes. The network is also being strengthened for offshore wind, other generators, demand and system security. But it would be equally wrong to pretend that the network comes at no cost.
National Grid explains that it pays the upfront cost of transmission investment and recovers approved expenditure from customers over time. Ofgem controls the revenue that regulated network companies may recover. Regulation affects the amount and timing of recovery; it does not make the infrastructure free.
No consolidated public figure currently shows how much of the Navenby works and wider reinforcements will be funded by developers, how much will enter the regulated network cost base, or what cancellation liabilities would remain if individual projects were delayed or abandoned.
Eight separate applications but no single bill
The planning system presents each solar scheme as a separate application. Company accounts present each project as a separate legal entity. Network documents divide the work into individual connection and reinforcement entries.
That structure makes the cumulative cost difficult for the public to see.
The figures already available show:
• eight applications with about 4,100 MW of proposed solar capacity
• a central construction benchmark of £2.702 billion, before batteries, wider grid works and finance
• at least £65.745 million owed within seven comparable project companies
• £1.965 million of identified interest or capitalised borrowing cost across four companies and differing periods
• an illustrative £1.407 billion of interest if 70 per cent of the central construction estimate were borrowed for 20 years at 6 per cent
These numbers do not prove that every scheme is uneconomic, and the debt illustration must not be added mechanically to the company-account balances. They do prove that the public has not been shown one complete assessment of the money involved.
Before more nationally significant solar capacity is built, Parliament should require a cumulative assessment that answers four basic questions. What will the projects cost to build? What will financing add? Which grid works are required and who will pay for them? What support, network charges and other costs could ultimately reach consumers?
That is the purpose of the petition.
It asks for Climate Change Act targets to be suspended while a full national impact assessment examines the combined economic, energy-security, environmental and social consequences.
MAKE THEM SHOW THE FULL COST.
Sign the Parliamentary petition to suspend Climate Change Act targets and undertake a full national impact assessment
The petition closes on 21 March 2027.
Sources and limitations
• DESNZ and Arup cost assumptions for onshore wind and solar
• NESO connections registers and reports
• Planning Inspectorate East Midlands infrastructure projects
• National Grid Navenby Substation
• Ofgem energy network price controls
• Companies House filing histories for the eight project companies
Connection dates do not prove construction or energisation. Project capacities can differ from export limits and combined solar-plus-storage capacities. Amounts owed in company accounts cover different categories and accounting periods. The financing example is a sensitivity calculation, not evidence of the projects’ final capital structures.
Leave a comment