Grazeley Solar Farm: What Does £10 Million of Lifetime Profit Really Mean?

A solar farm can make money for forty years and still be a poor investment. That sounds contradictory only because “profit” is doing too much work.

A recent BBC/LDRS report on West Berkshire Council’s Grazeley Solar Farm says the project is expected to make about £10 million over a 40-year lifetime. The same report describes an £18.6 million project, 20MW of capacity, roughly 35,000 panels and a grid-connection deadline in December 2027. Those numbers make an obvious headline. They do not yet tell us what return the investment earns. [1]

There is another complication. The £18.6 million figure is already out of date. West Berkshire Council’s current September 2026 FAQ puts the estimated project cost at £16.2 million, including design, development, construction and two years of maintenance. It says £1.2 million has already been spent, the plant will have 20MWp of capacity and annual generation will be just under 20,000MWh. The Council says the scheme has been modelled over 30 years, although it expects the asset to remain profitable for longer. [1]

That changing number points to the more useful question: what does Grazeley have to earn on each megawatt-hour for the project to create financial value after capital cost, degradation, maintenance, replacement spending and the timing of the cash flows are taken into account?

£10 million is not £10 million

Adding forty years of profit together treats a pound received decades from now as though it were worth the same as a pound committed to construction today. Investment analysis cannot do that.

A long-lived asset has to compensate for the capital tied up at the beginning, the risk that future revenues disappoint and the fact that money received later is worth less than money received sooner. This is why infrastructure investors use measures such as net present value (NPV) and internal rate of return (IRR) rather than relying on lifetime profit alone.

The distinction is not cosmetic. In our downside scenario, Grazeley still produces about £1.1 million of positive cumulative cash over thirty years, yet its NPV is approximately negative £8.7 million and its project IRR is only about 0.5%. A lifetime-profit number can therefore turn positive while the investment still destroys value. [3]

Rebuild the solar farm from the electricity up

A 20MWp rating is the maximum output of the installed panels under specified conditions. It is not 20MW delivered every hour of the year. The Council expects Grazeley to generate just under 20,000MWh annually. We use 19,800MWh as a transparent modelling proxy, which implies a first-year load factor of about 11.3%. [2]

The Department for Energy Security and Net Zero’s Arup study gives large-scale solar load factors of 11.5% to 14.5% and a medium annual degradation assumption of 0.30%, so the public Grazeley output is broadly in range. At £16.2 million, Grazeley also works out at about £810 per kWp, near the top of Arup’s £526-£788/kWp generic range. The comparison is not clean because the price bases and cost boundaries differ, but it provides a useful scale check. [2]

The number that matters is the price Grazeley actually captures

The Council’s August 2025 FAQ provides a useful historic clue. At that stage it expected roughly £1.7 million of annual revenue from exporting electricity to the grid. Divide that by our 19,800MWh generation proxy and the implied electricity price is approximately £85.9/MWh. [2]

That is not a current forecast. It is a public anchor. The relevant market variable is the captured price: what Grazeley actually earns in the hours when its solar output is produced, which can differ from an annual average electricity price.

Using the current £16.2 million project cost, a year-one output of 19,800MWh, the historic £85.9/MWh price anchor, 0.30% annual degradation, the Council’s historic £200,000 annual O&M estimate after the first two maintenance years, and a transparent allowance for periodic inverter replacement, our 30-year model produces a project IRR of about 7.7%. At a 7% nominal financial discount rate, NPV is approximately £1.0 million. [3]

More revealing is the break-even result. Under the same operating assumptions, Grazeley needs a constant nominal captured electricity price of about £81.5/MWh to produce an NPV of zero at a 7% required return. At a 5% hurdle rate, that falls to about £69.4/MWh. [3]

So the public-evidence case is financially positive, but it is not sitting on an enormous cushion. The electricity price and required return do a great deal of work.

Borrowing can explain the old £400,000 surplus number

The current Council FAQ says the initial capital outlay will be funded through capital borrowing. The exact project loan structure is not public, so we use a financing reference rather than pretending to know the Council’s debt schedule. [4]

Approximately £15 million of the current £16.2 million project cost remains after the disclosed £1.2 million already spent. Amortising £15 million over thirty years at 5.4%, the Public Works Loan Board rate cited by the Council in February 2026, gives annual debt service of about £1.02 million. [4]

Now place that beside the older public figures:

£1.70m revenue
minus £0.20m O&M
minus £1.02m reference debt service
= about £0.48m annual cash surplus

That is strikingly close to the Council’s August 2025 estimate of up to £400,000 per year.

It is not proof that we have reverse-engineered the Council model. We have not. The simple bridge excludes periodic replacement expenditure, reserves, other costs and any difference between the Council’s actual borrowing structure and our reference loan. But it shows that the older surplus claim was not arithmetically mysterious. A plausible financing structure can reconcile it surprisingly well. [4]

It also exposes a project-finance issue hidden by a smooth annual-profit figure: periodic replacement spending can create much tighter cash years than the average suggests, so lifecycle reserves matter.

The solar panels may not be the scarce part of the project

West Berkshire Council’s leader summarised Grazeley in one unusually useful sentence: the Council has the land, the planning permission and the slot in the grid.

Those are not incidental details. They are complementary assets.

A viable solar development needs a site, consent, a cable route, network access, financing and a buyer on acceptable terms. Remove one and the value of the rest can collapse.

Grazeley already has planning permission and a grid connection. The reported December 2027 energisation deadline therefore has economic value because delay pushes every future cash flow further away. In our public-evidence case, delaying the same thirty operating years by one year reduces NPV by roughly £1.06 million at a 7% discount rate. [5]

That £1.06 million is not the market value of the grid connection. Public information does not tell us what would happen if the deadline were missed: whether the connection would be delayed by months or years, reduced in size or lost altogether. But the calculation shows why grid access can be worth far more than an administrative line in a planning file.

The route to the buyer matters too. In 2022, the Council evaluated an earlier 18MWp version of Grazeley under two arrangements. A direct-grid option produced a reported 5.62% IRR. An AWE-linked option, which contemplated long-term contracted offtake and potentially selling around 73% of generation to AWE, produced a reported 7.60% IRR despite having the higher project cost. Those numbers belong to an old design and cannot be transplanted into the current project. Their lesson survives: how electricity reaches a buyer can materially change the return on the same underlying generation asset. [5]

Financial return is not the whole public-sector case

Grazeley is also intended to reduce the Council’s carbon emissions and create local environmental benefits. Those effects can matter economically without appearing as project revenue. They belong in a broader public-sector appraisal, not inside the solar farm’s IRR as an invisible subsidy to the calculation. [6]

The land is similar. Council ownership removes an acquisition payment, but not the value of the land’s next-best use. Because the public record does not support a reliable annual land value, the central model does not invent one. Financial return, social value and alternative public uses of capital should remain separate calculations. [6]

So can Grazeley make £10 million?

The public information is not sufficient to verify the Council’s current £10 million lifetime-profit claim. The detailed business case is confidential, and we do not know the current electricity-price curve, exact financing structure, local-sale terms or complete lifecycle-cost schedule.

But the available numbers tell us considerably more than the headline alone.

A transparent reconstruction using the current £16.2 million project cost and the historic £85.9/MWh revenue-implied price produces about 7.7% project IRR and approximately £1.0 million of NPV at a 7% required return. The project breaks even at roughly £81.5/MWh under those assumptions. A weaker combination of power prices, construction costs and generation can still produce positive lifetime cash while destroying substantial present value. [3]

The interesting asset is therefore not simply 35,000 solar panels sitting on agricultural land. It is an assembled development package: land + permission + grid access + generation + financing + a route to market.

That is what a solar farm is actually worth. Not the nominal profit number accumulated at the end of forty years, but the present value of what the complete project can deliver while the constraints around it are still satisfied.

Research note. This is an independent scenario reconstruction from public evidence, not West Berkshire Council’s confidential business case. The central model uses a historic public revenue estimate to derive an £85.9/MWh captured-price anchor; it is not presented as a current electricity-price forecast. The model excludes tax and uses explicit assumptions where current lifecycle costs are not public. Results should therefore be read as conditional investment scenarios, not as audited Council returns.

Explore the research

The technical report develops the generation, captured-price, capital-cost, financing, break-even, lifecycle and grid-timing analysis. The accompanying Grazeley Solar Investment Model contains the live cash-flow model, debt schedule, scenario cases, sensitivity tables and source register.

Sources and research

[1] Trigger, current cost and project facts. BBC / Local Democracy Reporting Service, “Solar farm approved for development” (25 September 2026); West Berkshire Council, “Grazeley Solar Farm: frequently asked questions” (updated September 2026). The £16.2m current cost, £1.2m spent, 20MWp capacity and “just under 20,000MWh” generation figure come from the Council FAQ; the £10m lifetime-profit and December 2027 connection-deadline framing come from the trigger article and are treated as reported claims rather than independently audited outcomes.

[2] Generation, degradation and capital-cost benchmarks. Department for Energy Security and Net Zero / Arup, Renewable Energy Generation Cost and Technical Assumptions 2024 – Onshore Wind and Solar PV (14 July 2025); West Berkshire Council FAQ above. The 19,800MWh year-one value is a transparent Rokin proxy inside the Council’s “just under 20,000MWh” statement; the 11.3% load factor and £810/kWp comparison are derived values.

[3] Project return, break-even price and scenarios. Rokin Research, What_Is_a_Solar_Farm_Actually_Worth_Redesigned_v2.pdf, Section 4 and Appendix A; Grazeley_Solar_Investment_Model.xlsx. The 7.7% IRR, approximately £1.0m NPV at 7%, £81.5/MWh break-even price, downside/upside cases and £1.1m-positive-cash / negative-£8.7m-NPV contrast are Rokin scenario outputs, not West Berkshire Council forecasts.

[4] Borrowing reference and historic surplus bridge. West Berkshire Council FAQ above; West Berkshire Council, Council meeting, 26 February 2026; Rokin Research technical report, Section 5. The approximately £1.02m annual debt-service figure uses a simplified £15m, 5.4%, 30-year reference case and is not presented as the Council’s final financing structure.

[5] Grid timing and route to market. West Berkshire Council, Grazeley Solar Farm Project Update, Executive, 15 December 2022; BBC/LDRS trigger above; Newbury Times, “Grazeley Solar Farm: Council Backs £15m, Bids to Supply AWE” (28 September 2026). The historic 5.62% and 7.60% IRRs belong to an earlier 18MWp design; the approximately £1.06m one-year timing loss is a Rokin sensitivity, not a standalone market valuation of the grid connection.

[6] Public-sector and appraisal boundary. West Berkshire Council, “Council approves next steps for Grazeley Solar Farm” (24 September 2026); HM Treasury, The Green Book 2026; Rokin Research technical report, Section 7. Financial project return, social/environmental value and land opportunity cost are kept as distinct analytical ledgers.