Commercial Solar Grants & Incentives 2026
Every UK commercial solar incentive in one place: AIA, Smart Export Guarantee, IETF industrial grants, Salix 0% loans, PSDS, and Business Energy Scotland — with rates, eligibility, and a worked example.
100% AIA
First-year tax relief
3–6p/kWh
SEG export rate
25–45%
IETF grant for industry
0% loans
Salix for public sector
Commercial Solar Grants and Incentives UK 2026
Commercial solar in the UK benefits from a stack of financial incentives that, in combination, can dramatically reduce the effective cost and improve payback to under 3 years for qualifying businesses. This page covers every incentive available in 2026 — from the universally available Annual Investment Allowance to sector-specific grants for manufacturers, public sector bodies, and community organisations.
Unlike domestic solar where a single 0% VAT benefit is the main incentive, commercial solar sits within a framework of overlapping business tax relief, capital grant, loan, and export income mechanisms. Understanding how these stack is essential to optimising your project's financial case.
1. Annual Investment Allowance (AIA) — Universal
The AIA is available to every UK business paying Corporation Tax or Income Tax (including sole traders and partnerships). It provides 100% first-year capital allowance on qualifying plant and machinery, including solar panels, inverters, racking, monitoring equipment, and associated electrical works.
| Business Type | Tax Rate | Saving on £100k Install | Effective Net Cost |
|---|---|---|---|
| Company (small profits rate) | 19% | £19,000 | £81,000 |
| Company (main rate) | 25% | £25,000 | £75,000 |
| Sole trader (basic rate) | 20% | £20,000 | £80,000 |
| Sole trader (higher rate) | 40% | £40,000 | £60,000 |
| Sole trader (additional rate) | 45% | £45,000 | £55,000 |
| LLP (mixed rates) | 20–45% | £20,000–£45,000 | £55,000–£80,000 |
AIA limit is £1,000,000/year — sufficient for any commercial solar installation.
2. Smart Export Guarantee (SEG)
The SEG requires electricity suppliers to pay businesses and organisations for surplus solar electricity exported to the grid. Every MCS-certified solar system is eligible. The SEG applies to any amount of surplus electricity — there is no maximum or minimum export volume.
| Supplier | SEG Tariff (2026) | Terms | Notes |
|---|---|---|---|
| OVO Energy | 6.5p/kWh | Fixed 12 months | Best fixed rate |
| E.ON Next | 5.5p/kWh | Variable (quarterly) | Large supplier |
| EDF Energy | 5.0p/kWh | Variable | Direct debit required |
| Octopus Energy | 4.1p/kWh | Variable (Flux) | Higher off-peak rates possible |
| British Gas | 3.5p/kWh | Variable | Widely available |
| ScottishPower | 3.0p/kWh | Variable | Scotland specialist |
SEG tariffs change periodically. Larger commercial generators (250kWp+) should explore direct PPA contracts at 8-12p/kWh.
3. Industrial Energy Transformation Fund (IETF)
The IETF is the primary capital grant programme for large industrial energy users. Phase 3 (2024 onwards) offers:
- Feasibility Study stream: grants up to £250,000 for energy efficiency studies (not solar itself, but solar can feature as an option in the study)
- Deep Dive stream: grants of 25–45% of capital cost for qualifying decarbonisation projects including commercial solar
- Qualifying criterion: site energy consumption above 1GWh/year OR energy spend above approximately £200,000/year
- Sectors: manufacturing, food processing, chemicals, glass, ceramics, iron and steel, paper, and other energy-intensive industries
- Application portal: gov.uk/government/publications/industrial-energy-transformation-fund
A qualifying manufacturer installing a 500kWp solar system for £330,000 could receive an IETF grant of £82,500–£148,500 (25–45%), plus AIA on the remaining cost. Combined, these incentives can reduce the net investment to £100,000–£130,000 — payback under 2 years on a well-sited industrial system.
4. Salix Finance (Public Sector)
Salix Finance provides interest-free loans to eligible public sector organisations for energy efficiency and renewable energy projects. The loan is repaid from the energy savings generated — so the organisation pays nothing upfront beyond project management.
- Eligible bodies: local authorities, schools and academies, NHS trusts, universities, housing associations, emergency services, central government departments
- Project eligibility: any project with payback of 2–10 years qualifies (commercial solar typically 3–7 years)
- Loan amount: typically the full capital cost of the installation
- Application: via the Salix Finance online portal (salixfinance.co.uk)
- Process: application review (4–8 weeks), approval, installation, loan drawdown
5. Public Sector Decarbonisation Scheme (PSDS)
PSDS Phase 4 (2024–2026) provides capital grants for public sector decarbonisation projects. Solar PV can be included as part of a broader project. Grant levels depend on the organisation's deprivation index and regional allocation. For hospitals, schools, and councils in deprived areas, grants of up to 90% of project cost have been awarded. Applications through your local Energy Hub (England) or equivalent.
6. Business Energy Scotland (BES)
For Scottish businesses, Business Energy Scotland (managed by the Energy Saving Trust) offers: free energy audits, grants up to £10,000 for SMEs, and interest-free loans up to £500,000 for energy efficiency and renewable projects. Applications via Business Energy Scotland online portal.
Stacking Incentives: A Worked Example
A food manufacturer in the East Midlands installs 400kWp of commercial solar for £260,000:
| Incentive | Mechanism | Value |
|---|---|---|
| IETF grant (30%) | Capital grant — non-repayable | −£78,000 |
| AIA (25% CT on remaining cost) | Tax deduction: £182,000 × 25% | −£45,500 |
| SEG export income (yr 1) | 10% export × 352,000 kWh × 5p | +£1,760/yr |
| Avoided electricity (yr 1) | 90% self-consumption × 352k × 22p | +£69,696/yr |
| Net effective outlay | £260,000 − £78,000 − £45,500 | £136,500 |
| Payback (effective) | £136,500 / £71,456 total year-1 benefit | 1.9 years |
Get a Grants Assessment
We assess your eligibility for AIA, IETF, Salix, and SEG as part of every commercial solar proposal — at no additional cost. All incentives maximised in your project economics.
Request Grants AssessmentKey Dates and Application Deadlines
- IETF Phase 3: ongoing — applications accepted on a rolling basis until fund exhausted. Budget is £185m — apply early.
- PSDS Phase 4: applications typically close in autumn each year. Check gov.uk for current window.
- Salix: applications accepted year-round. No deadline — loans available until Salix's annual allocation is committed.
- AIA: always available — no deadline, no application needed. Claimed on annual tax return.
- SEG: register with your chosen supplier after MCS certification — no deadline.
Frequently Asked Questions
What is the Annual Investment Allowance for solar?
The Annual Investment Allowance (AIA) allows UK businesses to deduct 100% of qualifying capital expenditure from taxable profits in the year of purchase. Solar panels, inverters, racking, cabling, and installation labour all qualify as plant and machinery under the AIA. The current AIA limit is £1,000,000 per year — more than sufficient for any commercial solar installation. At the 25% Corporation Tax rate, a £100,000 solar installation generates a £25,000 tax saving in year one. Sole traders and partnerships paying income tax at 40–45% benefit proportionally more.
What is the Smart Export Guarantee (SEG)?
The Smart Export Guarantee (SEG) requires licensed electricity suppliers with 150,000+ customers to offer export tariffs to small-scale generators. Any solar system up to 5MWp with MCS certification can receive SEG payments for surplus electricity exported to the grid. SEG tariffs in 2026 range from 3.0p/kWh (Octopus Flux baseline) to 6.5p/kWh (OVO Energy fixed). The SEG replaced the old Feed-In Tariff (FiT) for new installations. Commercial systems should also explore Power Purchase Agreements (PPAs) with energy traders for larger export volumes.
What is the Industrial Energy Transformation Fund (IETF)?
The IETF is a government grant programme for industrial businesses with annual energy spend above approximately £200,000 (roughly 1GWh/year consumption). It offers capital grants of 25–45% for qualifying energy efficiency and decarbonisation projects, including commercial solar. Phase 3 of the IETF opened in 2024 and has a total budget of £185 million. Applications are made to the Department for Energy Security and Net Zero (DESNZ). Eligible businesses are primarily manufacturers, food processors, and large energy-intensive service providers.
Can public sector organisations access 0% loans for solar?
Yes. Salix Finance provides interest-free loans to eligible public sector organisations — including schools, academies, local authorities, NHS trusts, universities, housing associations, and police and fire services — for energy efficiency improvements including solar. Loans are repaid from the energy savings generated, meaning the net cost to the organisation is zero. Salix loan applications are assessed on the payback of the proposed project — commercial solar typically has payback of 3–7 years, well within Salix's lending criteria. Applications are made directly to Salix Finance via their online portal.
Is VAT reduced on commercial solar panels?
As of 2023, solar panels installed on commercial buildings are subject to 20% standard-rate VAT (not the 0% rate that applies to domestic installations). VAT-registered businesses can reclaim this input VAT on their next VAT return, making VAT neutral for most commercial buyers. Non-VAT-registered organisations — charities, small businesses below the VAT threshold, non-trading community groups — cannot recover VAT and should factor the 20% into their net cost calculations. For public sector bodies, the Public Sector Refund Scheme (Section 33 VAT Act) allows certain bodies to reclaim VAT directly from HMRC.
What is the Public Sector Decarbonisation Scheme (PSDS)?
The Public Sector Decarbonisation Scheme provides grants for public sector organisations to decarbonise their heating and energy systems. Phase 4 (2024–2025) focuses on low-carbon heat (ASHP, GSHP) but solar PV can be included as a complementary measure alongside heat pump installations in a combined decarbonisation project. Grant levels under PSDS Phase 4 are up to 90% for lower-income areas and 50–75% elsewhere. Applications must be led by a public sector anchor organisation (council, NHS, university) but can include associated third-sector or community assets.