Grants and funding for Commercial Solar PV

How commercial solar is funded in the UK

There is no single headline grant that pays for a commercial solar PV system the way domestic schemes once did. Instead, the economics of a business install come from a stack of tax reliefs, export income and, for specific sectors, targeted grant funding, layered on top of the underlying bill saving. Together these routes bring the effective net cost well below the headline price, which is why typical commercial payback lands at 5 to 8 years. Most are not mutually exclusive: a profitable, VAT-registered company can claim the tax relief, reclaim the VAT and earn export income on the same system at once. This page explains each route, who qualifies, what it is worth and how you apply, then how they stack and where businesses trip up. The grant cards below give the official links and current figures, and our real-world UK pricing guide covers cost per kWp across the 30 kW to 2 MW range.

100% Annual Investment Allowance, the main lever

For almost every commercial buyer, the single largest financial lever is the 100% Annual Investment Allowance. Solar PV qualifies as plant and machinery, and the AIA lets a business deduct the full capital cost from its taxable profit in the year of purchase, up to the £1m annual cap. Most commercial installs sit comfortably below that cap and are fully expensed in year one.

The value is straightforward. A profitable company that spends £100,000 on a qualifying system deducts the whole £100,000 from taxable profit that year, saving roughly £25,000 at the main corporation tax rate, so the AIA cuts the effective net cost by around a quarter. It is a deduction against profit rather than a cash grant, so the benefit is only as large as your tax bill: a business making little or no taxable profit gets little or no immediate value from it.

Eligibility is broad: UK businesses paying corporation tax, buying the asset outright or, in most cases, on hire purchase. There is no application form to file with a government body, you claim the allowance through your normal company tax return, so the process runs through your accountant rather than a separate scheme. Where a project exceeds the £1m cap, Full Expensing delivers a comparable first-year deduction. Keep the fixed-price invoice and commissioning paperwork, because those evidence the qualifying expenditure and the date it was incurred.

VAT: reclaimable, not zero-rated

This is the point most commonly misunderstood, so it is worth being precise. The 0% VAT relief that made headlines applies only to domestic installations. It does not apply to commercial solar. A business install is charged VAT at the standard rate. That VAT is reclaimable for a VAT-registered business, recovered as input tax through the ordinary VAT return, provided the system is used for taxable business activities.

So the VAT does not stay a real cost, but the mechanism differs from a discount: you pay it to the installer, then reclaim it from HMRC on your next return, so cash-flow modelling should account for the short gap between paying and reclaiming. Businesses that are not VAT-registered, or partly exempt, recover less or none of it, so confirm this with your finance team. Never rely on any claim that commercial solar is 0% VAT, it is not, and a proposal that says otherwise has the tax treatment wrong.

Smart Export Guarantee, income for the surplus

No commercial building consumes 100% of what its array generates. Even a busy warehouse exports some power at weekends, and offices, retail units and schools export a good deal more. The Smart Export Guarantee pays you for that exported surplus: any MCS-certified PV system up to 5 MW exporting to the grid can register for an SEG tariff with a licensed supplier.

Rates vary by supplier and tariff, typically running from around 4p to 15p per kWh, so it pays to shop the tariff rather than accept the first offer. For buildings without round-the-clock demand, offices, retail and schools that export 25 to 45% of what they generate, a competitive SEG tariff is a genuine part of the economics; for a 24/7 manufacturing site self-consuming 80% or more, it matters less because there is little surplus to sell. The application is administrative: you need a MCS certificate and an export-capable meter, then you register with an SEG-licensed supplier. The export rate is always well below what you save by using power on site, which is why every design maximises self-consumption first and treats SEG as the reward for the surplus. You can see how the two interact for your building using our savings calculator.

Industrial Energy Transformation Fund, for energy-intensive manufacturers

The Industrial Energy Transformation Fund is a competitive grant aimed at energy-intensive manufacturing and industrial sites in England, Wales and Northern Ireland. Unlike the tax reliefs above, this is genuine grant money toward the deployment and feasibility of energy-efficiency and decarbonisation measures, with individual grants typically starting from £100,000 upward. It suits larger factory and process-heavy installs where solar forms part of a wider decarbonisation case.

The IETF runs in phases with defined open windows rather than on demand, so timing matters. Applications are competitive and evidence-heavy: you generally need energy consumption data, a technical description of the measures, projected carbon and energy savings, and costed quotes. Lead times run to several months from expression of interest to award, so it is planned around, not tacked on at the last minute. Because the fund is manufacturing-specific, it is most relevant if you run a plant with high, steady process load. If that is you, read the sector detail on our solar for factories and manufacturing page, then check the current IETF window before committing.

Salix and the Public Sector Decarbonisation Scheme

Public bodies have their own dedicated routes. Salix Finance administers the Public Sector Decarbonisation Scheme (PSDS), which provides grant funding and interest-free loans for solar and wider decarbonisation across schools, the NHS, colleges and councils. For many public buildings this is the primary funding route, covering a substantial share of a project rather than nibbling at the edges.

The mechanics differ from the private-sector routes in one crucial respect: PSDS and Salix funding is applied for centrally by the public body itself, through the scheme's own process, not by the installer on your behalf. The body prepares the bid, usually with supporting energy and carbon data, and the funding attaches to the organisation. The scheme runs in phases with fixed bidding windows and finite budgets, so it is competitive and time-limited, and public procurement rules (framework or tender) then apply to the works. If you manage a school, trust, NHS estate or council building, the sequence is: confirm the current window, prepare the bid, and procure compliantly. Our solar for schools and public buildings page covers the sector specifics, including estate-wide rollouts across a multi-academy trust or authority.

Regional and combined-authority business grants

Below the national schemes sits a shifting layer of regional and combined-authority support. Combined authorities such as Greater Manchester, the West Midlands, West Yorkshire and Liverpool City Region periodically run SME decarbonisation grant rounds, typically worth £5,000 to £50,000 per business toward energy-efficiency and renewable measures, and local Growth Hubs sometimes run their own schemes alongside these.

The defining feature of this layer is that it opens and closes. A round that funded a neighbour's install last year may be closed, oversubscribed or replaced this year, and eligibility varies from region to region. Before committing to any route, it is worth a call to your combined authority or Growth Hub to ask what is currently open, because a modest regional grant can meaningfully improve an already sound business case. We flag any live regional scheme relevant to your location as part of the proposal.

How the routes stack

Commercial solar economics work because these routes combine rather than compete. Take an owner-occupied case: a profitable, VAT-registered company buys a system outright. It reclaims the VAT through its normal return; it claims 100% Annual Investment Allowance, deducting the whole net capex from taxable profit in year one and saving roughly a quarter of the cost in corporation tax; and it earns Smart Export Guarantee income on every unit it exports, on top of the bill saving on every unit used on site. Three levers, one system, all at once.

Sector-specific grants layer on top where they apply. An energy-intensive manufacturer might part-fund the capital through the IETF and cover the balance with AIA on the non-grant-funded portion; a public body funds the bulk through Salix or PSDS; a regional SME grant can offset part of the upfront cost. The one point to watch is that grant funding and capital allowances interact: you generally cannot claim tax relief on expenditure a grant has already paid for, so the AIA applies to the portion you funded yourself. That is an accountant's calculation, not a reason to avoid stacking.

Finance structures sit alongside all of this. Asset finance spreads the cost over 5 to 7 years and is usually cash-flow positive from month one, because the finance payment is less than the bill saving it replaces, and you own the system at the end. A Power Purchase Agreement needs zero capex: a funder installs and owns the system and you buy the power at a fixed rate below grid price. We model cash, asset finance and PPA side by side on every quote, with the IRR for each.

Timelines, evidence and common pitfalls

Each route runs on its own clock, and getting the sequence right saves months. The tax reliefs (AIA and VAT reclaim) are handled through your normal returns after the system is bought and commissioned, so they need no advance application, just clean paperwork. SEG registration happens after commissioning too. The grant routes are the ones with hard deadlines: IETF and Salix or PSDS run in fixed, competitive windows with finite budgets, so they are started well ahead of the install, not after it.

Whatever routes apply, the evidence pack is broadly the same: recent energy bills and, ideally, half-hourly meter data; a fixed-price quote for the works; projected generation, saving and carbon figures from a proper yield model; and, once installed, the MCS certificate and commissioning documents. That last set unlocks both the SEG income and the qualifying-expenditure evidence for the allowance.

The recurring pitfalls are worth naming:

• Assuming 0% VAT. It is a domestic-only relief. On a commercial install VAT is charged at the standard rate and reclaimed by VAT-registered businesses, so model the cash-flow gap between paying and reclaiming.
• Claiming AIA with no profit to deduct against. The allowance is a deduction from taxable profit, not a cash grant, so a loss-making year delivers little immediate benefit and the timing of the purchase can matter.
• Missing the grant window. IETF, Salix and PSDS run in defined phases. Expecting to apply after the panels are up is the most common way a genuine grant is lost.
• Double-counting grant and allowance. You cannot claim capital allowances on the part of the cost a grant has already funded, so the reliefs apply to the self-funded portion.
• Chasing SEG over self-consumption. Export earns 4 to 15p per kWh; power used on site saves 25 to 45p. A system oversized to sell to the grid is worse economics.
• Treating regional grants as guaranteed. They open and close and vary by area. Check what is live with your combined authority or Growth Hub first.

Funding commercial solar is a stacking exercise, not a single application, and the combined effect turns a six-figure project into a 5 to 8 year payback with 15 to 20 years of near-free power after. The right combination depends on your tax position, VAT status, sector and region, so we map the applicable routes for your building rather than quoting a generic list. To get that mapping, request a free no-obligation quote and we will model the funded position from your actual figures.