Same array, three quotes: how commercial solar finance companies price a 100kWp deal in 2026

A 100kWp rooftop array in the Midlands, installed cost £90,000 including a modest battery, on a profitable manufacturing business with three years of filed accounts. We ask a bank's green-loan desk, a specialist lessor and a PPA developer for terms. The replies land at roughly £1,250, £1,050 and £0 a month. None of those numbers is wrong; each answers a different question. Our guide to commercial solar finance companies sets out the provider types; this piece works one deal through all three.

Line one: the funding cost

Every funder starts from what money costs them. For a bank that is a margin over Bank Rate or SONIA. Bank Rate stood at 3.75% on 16 September 2026, down from the 5.25% it held from August 2023 to August 2024, so the same margin produces a cheaper loan than it did two years ago. On our £90,000 over seven years, a 150-basis-point fall in the base is worth about £1,300 a year. A lessor funds itself in the wholesale market and prices its rental off that cost plus what it expects the array to be worth to it at the end. A PPA developer's money is equity and project debt; its “rate” appears as the pence-per-kilowatt-hour price you pay for the power.

Line two: the margin

The margin is the funder's view of you. Three years of profitable accounts, positive net assets and a sector the credit team understands earn a margin of roughly 3 to 4 points over base at a bank; thin accounts or a single-customer business add one to three points. Lessors express the same judgement as an implicit rate inside the rental. PPA developers express it as a longer term or a higher price per unit. Whichever form it takes, the margin is the only line you can move quickly — by sending half-hourly consumption data, filed accounts and a clear ownership answer with the first enquiry.

Line three: fees and the term

Arrangement fees of 0.5% to 2% of the facility are normal on loans and hire purchase and are usually rolled in; leases bury documentation fees in the first rental; PPAs charge nothing upfront and recover it over 15 to 25 years. Term is the other lever: seven years at a bank against ten to fifteen at a lessor explains most of the £200 gap between the first two quotes, and it is a gap in timing, not in cost.

Line four: who owns the array

Modelled figures for illustration; the ranking is what matters. The cheapest monthly number is the lease, the cheapest lifetime number is the loan, and the cheapest upfront number is the PPA. A quote comparison that lines up monthly costs alone will pick the wrong one for most tax-paying businesses, which is why our seven-step financing guide puts the tax position first.

Five questions that make the quotes comparable

• What is the total cost of finance over the term, after tax, including the fee — not the monthly figure?
• Who claims the capital allowances, and has the quote priced their value in or left it with me?
• What happens at the end: ownership, a purchase option at what price, or hand-back?
• What is the break cost if the building is sold in year four?
• Is the rate fixed for the term, and to what is it indexed if not?

Read next: commercial solar financing and the companies that provide it, and the green loan lender comparison for the current rate bands by lender type.