Capital purchase + 100% AIA
Best for owner-occupiers and tenants on long leases. You pay capex upfront from cash or working-capital facility. Full project value expensed in year one under 100% AIA. For £900k install: £225k year-one tax shield, 3.1yr net cash payback, 22.4% 25-year IRR.
Asset finance over 5-10 years
Best for medium-lease tenants who want to own asset but spread capex. Lombard, Close Brothers, Aldermore, Shawbrook, Time Finance, plus green-finance specialists. Typical 2026 rates: 6.5-8.5% APR, 5-10 year amortisation, no security beyond asset itself.
Power Purchase Agreement (PPA)
Best for short-lease tenants, loss-making entities, off-balance-sheet preference. Third-party owns and operates system; you sign 20-25 year offtake at tariff 30-50% below grid retail. Zero capex. See dedicated /ppa-for-warehouses/ page.
Decision matrix
Owner-occupier or 10+ year lease + profitable + capex available → capital purchase. 5-10 year lease + want to own asset → asset finance. Under 7 year lease + zero capex preference + 500 kW+ → PPA. We model all three in every proposal.
Common questions
What's the cost of capital comparison?
Capital purchase + 100% AIA: ~3% effective cost of capital (after-tax). Asset finance: 6.5-8.5% APR. PPA: tariff differential to grid retail (effectively negative cost of capital — cash positive from day one). Different routes for different situations.
Can we mix financing routes?
Yes. Many large rollouts combine routes: cash for first £1m (AIA-optimal), asset finance for next £2m, PPA for any roof additional capacity. We structure the optimal mix in proposal.