Grants and funding for commercial solar panel installation
UK grants, tax reliefs, and finance routes for commercial solar panel installation. Updated for 2026.
UK commercial solar PV installation is supported by a mix of capital grants, tax allowances, and zero-capital finance routes. Most commercial projects we deliver combine two or three of these — for example, capital purchase plus 100% Annual Investment Allowance, or a Public Sector Decarbonisation Scheme grant covering 100% of capital plus a Low Carbon Skills Fund feasibility grant covering the upfront design work. Mapping the right funding stack to a specific project is part of every desk feasibility we deliver, and the right combination often improves project IRR by several percentage points compared to a default capital purchase route.
The funding landscape is dynamic — major UK schemes (PSDS, IETF) operate in funding windows with intake dates that change year to year, and the policy environment around capital allowances, tax reliefs, and energy market design is being actively reformed. We track the published guidance for every scheme in this list and refresh this page when material changes are announced. For the most current scheme-specific guidance, follow the official link on each entry below — those URLs are kept current.
Funding routes for UK commercial solar
Public Sector Decarbonisation Scheme (PSDS)
Applies to: NHS Trusts, schools, councils, central government estate
- Value
- Up to 100% capital grant, typical award £100k-£10m+
- How to apply
- Phase-based competitive funding — the next window typically opens in autumn each year. Salix Finance administers. Submit a low-carbon skills funded feasibility first to qualify.
Industrial Energy Transformation Fund (IETF)
Applies to: Manufacturing and energy-intensive industry
- Value
- 30-50% capital grant, typical project size £100k-£20m
- How to apply
- Phase 3 currently open; submitted via DESNZ portal. Requires energy audit and ETL or BAT-level technology specification.
Low Carbon Skills Fund (LCSF)
Applies to: Public sector bodies seeking decarbonisation feasibility
- Value
- 100% feasibility funding, typical award £20k-£100k
- How to apply
- Salix Finance — funds the feasibility study that then qualifies the project for PSDS capital. Quarterly intake.
Annual Investment Allowance (AIA)
Applies to: All UK businesses paying corporation tax
- Value
- 100% first-year capital allowance on plant and machinery up to £1m per year
- How to apply
- Claimed via corporation tax return. Solar PV qualifies as plant and machinery. Effectively reduces project net cost by 19-25%.
Power Purchase Agreement (PPA)
Applies to: Any commercial site with creditworthy 10-15 year tenancy
- Value
- Zero capital — installer funds and owns the system, sells energy back at fixed rate (typically 20-30% below grid)
- How to apply
- Direct via the installer or PPA fund. Requires credit check and lease commitment. Most viable for sites consuming 250,000+ kWh/year.
How these funding routes stack — worked combinations
The strongest commercial solar economics typically come from combining funding routes rather than relying on a single one. Five common combinations:
1. Public sector estate (school, NHS Trust, council building). Apply for a Low Carbon Skills Fund (LCSF) feasibility grant — covers 100% of the design and feasibility cost, typically £20-£100k. With LCSF complete, the project then becomes eligible for Public Sector Decarbonisation Scheme (PSDS) capital — up to 100% grant funding for the install itself. Combined: zero net cost to the public body. PSDS award typically ranges from £100k to £10m+ for solar PV combined with other decarbonisation measures.
2. Manufacturing site (factory, food production, energy-intensive industry). Apply for Industrial Energy Transformation Fund (IETF) Phase 3 capital grant — typically 30-50% of project cost. Combine with 100% Annual Investment Allowance on the remaining capital portion (giving 19-25% effective tax relief on that portion). Combined: 50-70% of project capital effectively grant or tax-relieved.
3. Commercial property (warehouse, hotel, office, retail). Most private commercial property doesn't qualify for capital grants but does benefit from 100% Annual Investment Allowance — full first-year capital deduction up to £1m per year, equivalent to 19-25% tax relief depending on corporation tax status. For projects above £1m, Structures and Buildings Allowance (SBA) covers a portion of the remainder over time.
4. Zero-capital approach for any creditworthy site. Power Purchase Agreement (PPA) — the installer or a PPA fund installs and owns the system, sells the energy back to the host at a fixed rate (typically 20-30% below grid retail). Zero capital, no balance sheet impact, no operational risk. Best for sites with strong creditworthiness and 10+ year lease commitment.
5. Multi-site portfolio. Bundle multiple sites into a single PPA or framework finance agreement to amortise the deal cost across the portfolio. For groups with 3+ sites, this typically delivers stronger commercial terms than per-site contracting and unlocks portfolio-level ESG reporting (Scope 2 reductions across the entire estate).
Application timelines — what to plan for
Most UK commercial solar grant schemes operate on intake windows with quarterly or annual deadlines. PSDS Phase 4 typically opens in autumn each year and closes within a few weeks; IETF Phase 3 has rolling intake but each phase has a budget cap that can close early. LCSF runs continuously but with quarterly assessment rounds. Annual Investment Allowance applies via the corporation tax return without a separate application. PPA contracting runs on the installer's commercial timeline — typically 8-12 weeks from initial enquiry to signed PPA contract.
Practical guidance: start the funding conversation at the same time as the technical feasibility, not after. Most failed grant applications fail because they were assembled too late, with insufficient evidence of need, or without the supporting structural and electrical surveys. We engage the funding workstream from the desk feasibility stage and align the proposal package with the relevant grant or tax route from day one.
Common pitfalls and how to avoid them
- Missing the intake window. Don't apply just-in-time — schemes often close earlier than published deadlines if budgets are committed.
- Insufficient half-hourly meter data. Most schemes require 12 months of half-hourly data to evidence the demand profile and self-consumption ratio.
- Underspecified system. Grant assessors look for clear evidence of system sizing methodology — PVSyst yield modelling, structural calcs, G99 letter — not back-of-envelope estimates.
- Capital allowance double-claim. AIA and grant funding can overlap but must be claimed correctly to avoid HMRC clawback. We coordinate with the customer's accountant on the right claim sequence.
- PPA contract terms. Some PPAs include indexation that makes year 15-20 economics worse than headline. Read the indexation clauses carefully and model long-term contractual cash flow before signing.