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Six finance structures · After-tax modellingFinance Structures

Six ways to finance commercial solar.

From outright capital purchase to zero-capital PPAs, every structure has a clear best-fit case. Here's the honest comparison — economics, mechanics, and trade-offs side by side. For a detailed comparison of when AIA beats FYA and how to combine both allowances, see our AIA vs FYA detailed comparison.

UK commercial solar finance — 2026 funding map

UK commercial solar finance in 2026 spans seven distinct structures, each with different mechanics, tax treatment, balance sheet impact, and best-fit profiles. The right structure for any specific project depends on your tax position, capex availability, balance sheet preferences, occupation horizon, and electricity supply preferences. We model all seven structures against your actual numbers in advisory engagement.

Most UK businesses approach commercial solar finance through an installer or a single lender. Both are commercially aligned with one specific finance route. We sit on your side of the table to recommend the structure that wins on your specific numbers — including recommending you don't proceed where economics don't support it. For guidance on selecting a qualified installer before engaging a finance provider, see our UK commercial solar installers guide.

The seven UK commercial solar finance structures: capital purchase (cash buy with full tax allowances), green loan (debt-funded ownership preserving tax allowances), finance lease (leasing-company structure with lessee tax-allowance capture), operating lease (off-balance-sheet under FRS 102 small-entity), Power Purchase Agreement (third-party owns and operates; you buy the electricity), asset finance / hire purchase (predictable monthly payments aligned with operating budget), and battery storage finance (combined with solar in specific scenarios).

For most UK profitable trading companies installing commercial solar in 2026, capital purchase delivers strongest lifetime economics — typically 16-22% post-tax IRR over 25 years, payback in 3.5-5 years post-FYA. Green loans provide the next-best alternative for working-capital-constrained operators. PPAs serve covenant-restricted businesses and capital-constrained operators. Operating leases serve covenant-prioritising operators where balance sheet treatment matters. Asset finance serves speed-critical or sub-£100k projects.

Beyond the structure choice itself, finance route selection interacts with: tax allowance capture (50% First Year Allowance extends to 31 March 2026), public-sector funding routes (PSDS for not-for-profits), customer ESG procurement requirements (retailer supply-chain financing), and regional combined-authority programmes. Our advisory approach models these interactions on your specific project rather than treating finance structure as a standalone decision.

F01

Capital Purchase

Indefinite — system life of 25–30 years

Pay cash, own the asset, claim the full tax relief — the simplest structure and almost always the most economic over 25 years.

Whether you're evaluating commercial solar financing options for the first time or comparing structures for a specific project, the decision tree below covers every viable UK route — with honest after-tax economics, not lender-influenced defaults.

Best for

Profitable corporation-tax-paying companies with available cash

F02

Green Loans

7–15 years; commonly 10 years

Borrow against the project, retain ownership, smooth the cash impact — green loans typically charge 6–9% APR for solar specifically.

Best for

Profitable companies wanting to preserve working capital

F03

Operating Lease

5–10 years; commonly 7 years

The leasing company owns the system; you pay a fixed annual rent. Off-balance-sheet, fully expensable, but you don't get the FYA.

Best for

Loss-making or low-tax-paying companies (the lessor uses the FYA, you get a lower rent)

F04

Finance Lease

5–10 years; commonly 7 years

Functionally similar to a loan — you pay over time, the asset hits your balance sheet, and you keep the tax benefits, but with leasing-company structure.

Best for

Profitable companies wanting to keep capital allowances

F05

Power Purchase Agreement (PPA)

15–25 years; commonly 20 years

A third party owns and operates the system on your roof; you buy the electricity at a fixed rate. Zero capital, zero responsibility, lower savings ceiling.

Best for

Capex-constrained businesses with strong electricity demand

F06

Asset Finance

3–7 years; commonly 5 years

Catch-all category for hire purchase, equipment finance, and similar structures aimed at SME-scale solar projects below £250k.

Best for

SMEs with smaller commercial systems (50kWp–200kWp)

F07 12–15 year calendar life

Battery Storage

Adds material project value in specific scenarios — export-constrained sites, time-of-use exposure, capacity-market eligibility, or resilience-critical operation.

Read in detail

Frequently asked questions

What are the 6 commercial solar finance options in the UK?
The six main routes are: (1) Capital purchase — own the system outright, claim FYA; (2) Green loan — borrow to own, retain tax allowances; (3) Operating lease — off-balance-sheet rental, lessor claims FYA; (4) Finance lease — on-balance-sheet, lessee claims allowances; (5) Power Purchase Agreement (PPA) — zero capital, pay per kWh; (6) Asset finance (HP) — shorter term hire purchase, SME-focused.
Which solar finance route has the lowest lifetime cost?
Capital purchase (using own cash) has the lowest 25-year total cost because it eliminates all financing charges and retains the full First Year Allowance. Green loan capital purchase is second — borrowing cost is partially offset by the FYA saving. Operating lease and PPA are the most expensive over 25 years but require no upfront capital. Finance lease and asset finance sit in between.
Can I finance commercial solar with no upfront capital?
Yes. Three routes require zero upfront capital: operating lease (fixed monthly rental, lessor owns system), Power Purchase Agreement (pay per kWh generated, provider owns system), and some green loans structured as 100% loan-to-value (though rare). Off-balance-sheet treatment is available for qualifying operating leases under UK GAAP.
How long does it take to arrange commercial solar finance?
Timeline depends on the structure: green loans from mainstream banks take 4–8 weeks; specialist asset finance lenders can complete in 2–3 weeks; operating leases require 3–5 weeks for credit approval and legal documentation; PPA contracts take 3–6 months due to the DNO connection application process. Independent modelling and lender shortlisting typically adds 1–2 weeks to any route.
Do I need a specific type of company to get commercial solar finance?
Most commercial solar finance products require the applicant to be a UK limited company or LLP with at least 2 years of trading history and audited accounts. Sole traders and partnerships can access some asset finance products. Public-sector bodies can access PSDS grants and Salix Finance loans. Loss-making businesses or those in certain restricted sectors (e.g. financial services, property development) may face additional criteria.

How to choose the right commercial solar finance structure

Six primary finance structures serve the commercial solar market. The optimal choice depends on four factors: the client's tax position (particularly FYA and AIA eligibility), balance-sheet objectives, appetite for long-term contractual commitment, and immediate cash availability. The table below summarises the decision logic.

FactorPoints to Capital PurchasePoints to Green LoanPoints to PPA / Lease
Tax positionFull FYA (50%) or AIA available; 25%+ corporation tax payerPartial FYA/AIA; interest deductibleNo tax appetite (charities, public sector, loss-making)
Balance sheetAsset capitalisation acceptableDebt acceptable; lower than outright purchaseOff-balance-sheet preferred (operating lease, PPA)
Cash positionStrong: can deploy capital at >12% IRRModerate: willing to service debt at 5–9%Weak or reserved: zero or minimal upfront cost preferred
Risk appetiteAccepts all performance riskAccepts performance risk; lender step-in for defaultTransfers performance risk to asset owner (PPA, operating lease)
Ownership objectiveWants to own the assetWants to own the assetIndifferent to ownership; prefers predictable electricity cost

Current market rates — commercial solar finance 2026

Finance markets for commercial solar have materially changed since 2022. Rising base rates (Bank of England base rate: 4.25% as of Q1 2026) pushed commercial green loan margins up, but increased competition among specialist lenders has kept all-in rates competitive for well-structured projects.

Green loans (secured term loan)

Typical all-in rate: 6.5–9.5% APR depending on project size, borrower credit profile, and whether the asset is being used as collateral. Smaller projects (<£200k) carry a higher margin — specialist lenders active here include Siemens Financial Services, Columbia Threadneedle, and specialist renewable energy lenders. Larger projects (£500k–£5m) attract 6.5–8% from tier-1 clearing banks with green loan frameworks (Barclays, HSBC, Lloyds).

Asset finance / hire purchase

Typical implicit rate: 7–11% depending on asset age, residual value model, and borrower credit. Asset finance structures do not require a security charge on property — the asset itself is the security. This makes it accessible for tenants and owner-occupiers without unencumbered property. Broking the transaction across 8–12 asset finance providers typically reduces the rate by 1–2 percentage points versus direct application.

Operating leases

Implicit rate: 8–12% embedded in the rental calculation. Quoted as £/kWp/month rather than an interest rate. Operating leases are off-balance-sheet under IFRS 16 only if the asset is treated as a service arrangement by the lessor — a commercially significant distinction. Confirm with your auditor before committing to off-balance-sheet accounting treatment.

Power Purchase Agreements (PPAs)

Electricity price: typically 85–92% of prevailing grid electricity cost at drawdown, fixed or indexed. Developer-funded PPAs require a 15–25-year term commitment — review change-of-control provisions (what happens if the building is sold), export provisions (what happens to excess generation above building consumption), and performance guarantees (what if the array fails to generate the contractual volume).

Tax incentive interaction with finance structures

The UK's 50% First Year Allowance (FYA) for qualifying commercial solar assets (active since April 2023, extended in the 2026 Budget) creates a significant asymmetry between owned and leased assets.

Capital purchase: maximum FYA benefit

Owner capitalises the asset at full cost. 50% FYA reduces the taxable profit in year 1 by half the asset cost. On a £500,000 system with 25% corporation tax, the year-1 tax saving is £62,500 — an immediate 12.5% return on investment before any electricity generation. Remaining 50% enters the main pool at 18% WDA.

Green loan / hire purchase: partial FYA benefit

Under HMRC rules, the hirer under a hire purchase agreement can claim FYA as if they are the owner — even if legal title does not transfer until final payment. Green loans secured against the asset similarly allow the borrower to claim FYA. This maintains most of the tax benefit while preserving cash via debt financing.

Operating lease and PPA: no FYA for the occupier

Under an operating lease or PPA, the asset remains on the lessor's / developer's balance sheet — they claim the FYA (reflected in the implicit rate they charge). The client claims no capital allowance. If the client is a 25%+ corporation tax payer with strong taxable profits, this is a material disadvantage worth quantifying: compare after-tax IRR of capital purchase vs operating lease before making the decision.

Commercial solar lender landscape 2026

The lender universe for commercial solar has expanded significantly since 2020. Prior to the pandemic, clearing banks were the primary source. Today, a competitive ecosystem of specialist lenders, challenger banks, and institutional funds serves the market.

Clearing banks with green loan frameworks

Barclays Green Loans, HSBC Sustainable Finance, NatWest Green Finance, and Lloyds Green Building Loans all offer solar-specific products. Advantages: competitive rates for

Specialist renewable energy lenders

Siemens Financial Services (UK), Columbia Threadneedle Infrastructure, Santander Corporate Banking, and specialist solar fund managers (Triple Point, Palatine, Gresham House) serve the mid-market (£200k–£10m). More flexible on project characteristics than clearing banks; faster decisions (4–6 weeks); willing to lend into lease/PPA structures.

Asset finance brokers and panels

For sub-£500k projects, specialist asset finance brokers (Nucleus Commercial Finance, Fleximize, Funding Circle Green) aggregate capacity from 8–20 UK asset finance providers. Broking adds a 0.5–1% margin but saves 4–6 weeks of bilateral lender management and typically produces better all-in rates than direct application to a single provider.

Public sector and not-for-profit lenders

PSDS Phase 4 grant (up to 67% capital contribution for NHS and local authorities), UKIB (UK Infrastructure Bank) green lending at concessionary rates, and Salix Finance (0% interest finance for public sector organisations) are available for eligible organisations. These are not accessible to private-sector businesses.