Commercial Solar Grants UK 2026

There is no single nationwide UK government cash grant for commercial solar PV in 2026 — but there are over a dozen regional, sector-specific and tax-relief schemes that effectively reduce net capex by 25–50% for businesses that fit. The trick is knowing which schemes apply to your business and how they stack. This page lays out the full UK landscape: AIA tax relief, SEG, Mayoral Combined Authority grants, IETF, Salix, devolved-government schemes, and the British Business Bank routes. For our canonical detailed guide including current application windows, see grants and funding.

The most universal route: 100% Annual Investment Allowance

Before any regional grant, every UK business installing commercial solar should understand AIA. The Annual Investment Allowance gives 100% first-year capital allowances on plant and machinery up to £1,000,000 of qualifying expenditure per accounting period. Solar PV qualifies. For a profitable UK limited company at the 25% main rate of corporation tax, AIA delivers year-one tax relief equal to 25% of the install cost — effectively reducing net capex by 25%. On a £100,000 install: £25,000 of corporation tax saved in year one, net effective capex £75,000. This is universal — every profitable Ltd Co qualifies regardless of region or sector. Sole traders and partnerships claim AIA at their marginal income tax rate (often higher than corporate tax). See capital allowances on solar panels for full mechanics. Note that AIA stacks cleanly with capital grants: if you receive a £30,000 grant on a £100,000 install, you can only claim AIA on the £70,000 net cost — but you still get the full £30,000 grant on top.

Smart Export Guarantee: ongoing per-kWh income

The Smart Export Guarantee (SEG), administered by Ofgem, requires licensed UK electricity suppliers with over 150,000 domestic customers to offer a tariff for exported renewable electricity from MCS-certified systems up to 5 MW. SEG is not a grant — it is a contractual income stream. SEG rates in 2026 vary widely by supplier and tariff structure: standard fixed-rate SEG tariffs from major suppliers (British Gas, EDF, E.ON, Octopus, OVO, Scottish Power, Shell Energy) sit at 4–7p/kWh; premium variable-rate tariffs (Octopus Outgoing Agile and similar TOU products) deliver 8–15p/kWh during peak hours, typically 4pm–7pm. A 100 kW commercial system with 25% export ratio (75% self-consumption) exports approximately 23,000 kWh per year — earning £920–£1,610 at standard SEG, or £1,840–£3,450 at premium SEG. We always shop SEG tariffs at commissioning and re-shop annually — switching adds 30–60 minutes of work and can lift annual SEG income by £500–£2,000 on a 100 kW system.

Mayoral Combined Authority green grants

Four major Mayoral Combined Authorities run capital grant schemes for SMEs in their footprint, typically offering 30–50% capital grants on commercial solar PV up to maximum award caps of £25,000–£100,000 per project. Eligibility usually requires SME status (under 250 staff, turnover under £50m), trading for 12–24 months, operating in the geographic footprint, and meeting specific sector or activity criteria. The four major schemes:

• Greater Manchester Combined Authority (GMCA) — Green Economy Hub and Manchester Climate Change SME funding. Typical award £15,000–£75,000 for solar PV.
• West Midlands Combined Authority (WMCA) — Net Zero Neighbourhoods and Business Energy Advice Service. Typical award £10,000–£100,000.
• West Yorkshire Combined Authority (WYCA) — Better Business Finance and Carbon Reduction Strategy grants. Typical award £10,000–£50,000.
• Liverpool City Region Combined Authority (LCRCA) — Net Zero LCR business support including capital grants. Typical award £10,000–£75,000.

Application windows open and close on rolling cycles — most schemes accept applications continuously while funds are available, with closure typically announced 4–8 weeks ahead. We advise applying with the install contract already drafted — Mayoral schemes typically expect to see a quote, project plan, and projected energy savings as part of the application pack. Funding is usually paid in arrears against project milestones — first 50% on contract signing and DNO acceptance, balance 50% on commissioning.

Industrial Energy Transformation Fund (IETF) for manufacturers

The Industrial Energy Transformation Fund (IETF), administered by the Department for Business and Trade and delivered through Innovate UK, is the largest single grant programme for commercial decarbonisation in the UK in 2026. Phase 3 of the IETF runs through 2028 with periodic application windows. IETF provides grant funding up to 30% of project cost (sometimes 40% for SMEs and projects in disadvantaged regions) for energy-intensive manufacturers (EIMs) — businesses in specific SIC codes including iron and steel, chemicals, ceramics, glass, paper, food and drink processing, dairy, brewing, plastics manufacturing, and rubber processing. Eligibility: business must be located in England, Wales or Northern Ireland (Scotland has separate routes), must be in an eligible SIC code, must have UK manufacturing as primary activity, and must be applying for an energy efficiency, deep decarbonisation or fuel switching project. Solar PV typically qualifies as an energy efficiency or decarbonisation project under IETF rules when paired with manufacturing energy reduction. Minimum project size £50,000 total cost; maximum grant £14m for transformative projects. Typical solar PV grant award £200,000–£2m. Application windows: Phase 3 Window 4 closes 2026; check current windows at gov.uk/IETF.

Salix Finance for public sector

Salix Finance, a non-departmental public body, provides interest-free loans for public sector decarbonisation projects through the Public Sector Decarbonisation Scheme (PSDS) and direct Salix loans. Eligible bodies include NHS trusts, schools, academies, multi-academy trusts, further education colleges, universities, local authorities, fire and rescue services, and central government departments. PSDS provides grants (not loans) up to 100% of project cost for low-carbon heating and energy efficiency, with separate windows. Direct Salix loans are interest-free with terms up to 8 years and are repaid from energy bill savings — typical repayment is structured so monthly bill savings exceed monthly loan repayment from year one. Solar PV is an eligible technology under both routes. Public sector bodies can stack Salix interest-free finance with capital grants from PSDS, and capital allowances do not apply (public bodies pay no corporation tax).

British Business Bank Recovery Loan Scheme

The British Business Bank Recovery Loan Scheme (RLS) provides government-backed loans up to £2m to UK SMEs for general business purposes including capex investment in energy efficiency and renewable energy. RLS provides an 80% government guarantee to lenders, which improves lender appetite and typically reduces interest rates by 1–2% versus equivalent unsecured commercial lending. RLS is not a grant — it is a loan with normal repayment terms — but the government guarantee improves access to capital for SMEs that might otherwise struggle to secure unsecured finance for solar PV. Eligibility: UK SME with turnover up to £45m, UK trading activity, viable business with reasonable credit profile. RLS can stack with AIA, SEG, and capital grants. See the British Business Bank website for current accredited lenders and application process.

UK Shared Prosperity Fund (UKSPF)

The UK Shared Prosperity Fund (UKSPF) is the post-Brexit replacement for European Structural Funds, administered locally by 192 local authorities and combined authorities. UKSPF allocates funding across three priorities: communities and place, supporting local business, and people and skills. Local authorities have substantial discretion over how UKSPF funds are deployed, and many are channelling funding into business decarbonisation including capital grants for solar PV. Typical UKSPF capital grant: 30–60% of project cost up to maximum award £10,000–£50,000 for SMEs. Eligibility and award levels vary substantially by local authority. To check what UKSPF schemes are running in your area, contact your local council's economic development team or business support service. UKSPF runs through 2028 in its current funding cycle.

Devolved-government schemes: Wales, Scotland, Northern Ireland

Wales: Business Wales (administered by the Welsh Government) delivers energy efficiency grants for Welsh SMEs through SMART Cymru and the Welsh Government Energy Service. Capital grants typically 30–50% of project cost up to £25,000–£100,000. Eligibility: Welsh-trading SME, project located in Wales. The Welsh Government Net Zero Wales Carbon Budget includes business decarbonisation funding routes accessed through Business Wales.

Scotland: Local Energy Scotland administers the Community and Renewable Energy Scheme (CARES), providing advisory funding and capital support for commercial renewable energy projects. Scottish Enterprise runs SME support including some renewable capex grants for high-growth Scottish businesses. The Scottish Net Zero Public Sector Buildings Fund supports public sector decarbonisation. Solar Together Scotland and similar local schemes occasionally run group-buy schemes with negotiated discounted pricing rather than capital grants.

Northern Ireland: Invest NI runs renewable energy support schemes for NI businesses including the NI Sustainable Energy Programme (NISEP) which provides funding through energy supplier obligations. The NI Energy Strategy 2050 includes business decarbonisation routes. NI businesses also access UK-wide schemes including AIA, SEG, RLS and IETF.

How grants stack: real worked examples

Example 1: 100 kW install for a Manchester SME (manufacturing). Capex £95,000. GMCA Green Economy Hub grant award £25,000 (26% of capex). Net cost after grant: £70,000. AIA on £70,000 = £17,500 year-one tax relief. SEG export income £1,800/year ongoing. Effective net capex year one: £52,500. Year-one savings (avoided import + SEG): £18,000. Simple payback on net capex: 2.9 years. 25-year DCF NPV at 7%: £415,000.

Example 2: 250 kW install for a West Yorkshire food processor. Capex £200,000. WYCA grant £40,000. IETF grant (food and drink SIC eligible) £30,000. Total grant £70,000 (35% of capex). Net cost after grants: £130,000. AIA on £130,000 = £32,500 year-one tax relief. SEG export income £4,200/year. Effective net capex year one: £97,500. Year-one savings: £45,000. Simple payback: 2.2 years. 25-year DCF NPV: £820,000.

Grant stacking discipline matters. The general principle: capital grants reduce eligible AIA expenditure. SEG runs alongside any capex relief throughout the asset life. IETF and Mayoral Combined Authority schemes generally allow stacking but check the small print — some grants prohibit stacking with other public funding above a certain percentage threshold (typically state-aid driven).

Application timeline and what to prepare

Most grant applications follow a similar pattern. Prepare four documents: a fixed-price quote from an MCS-certified installer (we provide this within seven working days of receiving your meter data), a 25-year DCF financial model showing simple payback, IRR and NPV (we share PVSyst yield model and DCF spreadsheet alongside every quote), a 12-month half-hourly meter data file from your supplier (we can request this on your behalf with letter of authority), and a brief project plan with proposed install timeline and milestones. Application timeline runs 6–16 weeks for most schemes — Mayoral grants tend to be faster (4–8 weeks), IETF can take 12–20 weeks. Plan accordingly: most installers will hold a quote price for 90 days, but grant decision delays beyond that may require a quote refresh.