PPA financing

Solar PPA Financing: How Zero-Capital Solar Is Funded

A solar PPA is, at its heart, a financing instrument. A third-party investor funds, owns and operates the system; you pay only for the kilowatt-hours it produces. This page explains who supplies the capital, why your capex is nil, and where the investor's return actually comes from.

A PPA is a financing decision before it is an energy decision

Most coverage of solar PPAs starts with the panels. That is the wrong end. Before a single module reaches your roof, a PPA is a structured-finance transaction — a way of procuring an asset you will use for decades without funding it yourself. The structure page sets out the physical and contractual types of PPA (on-site, sleeved, virtual and so on); this page looks underneath all of them at the money: who puts up the capital, how it is repaid, and what it costs.

The defining feature is that the off-taker provides no capital at all. You do not buy the inverters, you do not finance the cabling, and you do not carry the construction risk. A third party funds the entire build — on a 250kWp commercial rooftop that is an indicative £200,000–£260,000 of system capex, and on a 1MWp installation closer to £750,000–£950,000 — and recovers it through the tariff you pay per unit of electricity. In accounting terms you have converted a lumpy capital project into a predictable operating cost, which is precisely why finance directors reach for it.

That framing matters because it changes who you are really negotiating with. You are not haggling with an installer over a quote; you are agreeing terms with an investor who is underwriting two decades of your electricity demand and your creditworthiness. Understanding their economics is the fastest route to a sharper tariff.

Who actually funds the system

The capital behind a commercial PPA almost never sits with the company whose logo is on the proposal. It is held in a ring-fenced special-purpose vehicle (SPV) — a single-asset company created to own that one solar installation, isolate its risk and hold its contracts. The SPV signs the PPA with you, an EPC contract to build the system, and an O&M agreement to run it. You contract with the SPV, not with the fund standing behind it.

Behind the SPV sit several recognisable categories of funder, each suited to a different deal size:

• Specialist commercial rooftop solar funds — the typical backers of a single-site on-site PPA in the 100kWp–5MWp range, funding the system on your roof and selling you the kWh.
• Infrastructure-fund-backed SPVs — pools of institutional capital (pension and insurance money) that finance long-tenor, often multi-site programmes through SPVs where covenant strength and 20–25 year terms matter.
• Independent power producers and developers — who build utility-scale solar farms and contract the output to one large off-taker, the route behind most headline corporate PPAs.
• Utility and supplier corporate-PPA desks — who fund or source generation and sleeve it to multi-site portfolios via a licensed supply licence.

Our role sits outside all of these: we are an independent advisory and matching layer, not a funder. We explain the mechanics, set realistic tariff expectations and introduce you to vetted providers for a disclosed referral fee. The providers page sets out the full typology and which category fits which deal.

The capital stack: where the money comes from

Dig one layer deeper into the SPV and you find a classic project-finance capital stack — the same architecture that funds wind farms, toll roads and fibre networks. It has two tiers:

Layer	Typical share	What it is	Return it expects
Senior debt	60–80%	A bank or institutional lender, secured against the asset and the PPA cashflows, repaid first.	A fixed margin over the reference rate.
Equity	20–40%	The fund's own capital, repaid only after the debt is serviced — it carries the risk and the upside.	A 7–9% IRR over the contract life.

The lender takes step-in rights: if the SPV operator fails, the funder can replace it and keep the system running rather than let its security collapse. For you as the off-taker this is quietly reassuring — it means the party with the most to lose has the legal power to keep your panels generating, regardless of what happens to the original developer.

This is also why the off-taker covenant is scrutinised so heavily. The lender is, in effect, advancing money against your promise to buy electricity for 15–25 years. A stronger covenant lowers the lender's risk, which lowers the SPV's blended cost of capital, which the investor can pass through as a keener tariff. The relationship is direct and worth understanding before you go to market — see how term length drives the maths.

Why your capex is genuinely £0

The “zero capital” claim is not marketing shorthand — it is a structural consequence of the SPV owning the asset. Because the investor funds 100% of the design, equipment, construction, grid connection and commissioning, there is nothing for you to capitalise. No purchase order for plant, no drawdown on your banking facilities, no charge over your premises.

What you do pay are two much smaller, predictable items. First, your own legal and advisory costs on the contract — typically £8,000–£25,000 to have the long-form PPA reviewed, which is opex, not capex. Second, from the day the system is commissioned, the PPA tariff on every kWh generated — in 2026 indicatively 9–18 p/kWh on a typical on-site structure, against the 28–32 p/kWh many commercial off-takers pay for grid import. The detailed bands by system size and structure live on the PPA rates page.

Off-balance-sheet treatment and the IFRS 16 nuance

One of the most-cited reasons finance teams choose a PPA is off-balance-sheet treatment — keeping a multi-hundred-thousand-pound asset and its matching liability off the company's books, preserving headline gearing ratios and freeing borrowing capacity for the core business. This is often true, but it is not automatic, and the detail matters.

The pivotal accounting question under IFRS 16 is whether your PPA conveys the right to control the use of an identified asset. A well-structured PPA is drafted as a contract to buy electricity — an executory supply arrangement — not to lease the panels. Because the SPV retains control, dispatch and operational decisions over the system, the arrangement typically sits outside lease accounting and is expensed as you consume power. If, by contrast, the contract effectively hands you control of a specific, dedicated asset, an auditor may conclude it contains an embedded lease and require recognition of a right-of-use asset and lease liability — which defeats much of the off-balance-sheet rationale.

The practical implication: treat the accounting outcome as a drafting objective, not an afterthought. Loop in your auditors early, and make sure the heads of terms preserve the supply-contract characterisation. For larger corporates running a virtual PPA the relevant standard is different again — IFRS 9 hedge accounting and mark-to-market volatility, not IFRS 16 — which is one more reason the financing structure should be chosen with the finance function in the room.

PPA versus the other ways to fund solar

A PPA is one of five mainstream capital routes to a commercial solar system. They differ less on the panels — the hardware is broadly the same — and more on who owns the asset, who carries the performance risk, and what it does to your balance sheet. The table sketches the landscape; the dedicated comparison pages run the numbers.

Route	Capital you provide	Who owns the asset	Carries performance risk
Solar PPA	None — investor funds 100%	The SPV / investor	The investor
Cash purchase	Full system capex	You	You
Asset finance / HP	£0 down, then repayments to ownership	You (after the term)	You
Operating lease	Monthly rental	The lessor	You (you still rely on output)
Grant-funded	Part-funded; you fund the rest	You	You

The pattern is consistent: PPA is the only route that transfers both the funding and the performance risk to a third party, at the cost of forgoing the asset's long-run residual value. The right answer depends on your capital position, occupancy horizon and appetite to own and maintain plant. Work through the head-to-heads rather than taking a rule of thumb:

• PPA vs cash purchase — cashflow and admin versus lowest long-run cost.
• PPA vs asset finance — cheaper kWh now versus owning the system at the end.
• PPA vs operating lease — who carries under-performance risk.
• PPA vs grant-funded solar — which routes are stackable and which are mutually exclusive.

If, having weighed these, you decide you would rather own the system and want to compare funding lines, our sister资 site commercialsolarfinance.co.uk covers asset finance, leasing and capital routes for direct ownership in depth.

What this means when you go to market

Reframing a PPA as financing changes how you should approach procurement. You are sourcing capital and risk transfer, priced as a tariff — so the levers that move the price are financial, not technical. Three are within your control:

• Covenant — the stronger and more transparent your credit position, the lower the SPV's cost of capital and the keener the tariff you can command. A parent guarantee can unlock a better rate for a thinner trading entity.
• Term — a longer contract spreads the investor's recovery over more years and usually lowers the year-one rate; a shorter term raises it. Model the cumulative cost, not just the headline p/kWh.
• Demand match — a load profile that consumes generation on-site as it is produced improves the investor's revenue certainty and supports the cheapest structures.

The mistake we see most often is treating a PPA like a hardware purchase and optimising for the lowest install spec. The spec is the investor's problem; your job is to optimise the financing terms. We help commercial off-takers do exactly that — explaining the mechanics, benchmarking the tariff and introducing you to funders whose capital stack fits your covenant and term. Start with an indicative PPA quote, or get in touch to talk through which financing route fits your balance sheet.

FAQs

Frequently asked questions

Who provides the money for a solar PPA?

A third-party investor does — almost always through a special-purpose vehicle (SPV) backed by a specialist solar fund, an infrastructure fund, an independent power producer or a utility PPA desk. The SPV funds 100% of the system using a blend of senior debt (60–80%) and fund equity, then recovers its capital and return through the tariff you pay per kWh.

Why is a solar PPA genuinely £0 capex for me?

Because the SPV owns the asset, not you. It funds the design, equipment, construction and grid connection in full, so there is nothing for you to capitalise — no purchase of plant and no drawdown on your facilities. You pay only your own legal review costs (typically £8,000–£25,000) and then the per-kWh tariff once the system is generating.

Where does the investor's return come from?

From the tariff itself. Over a 15–25 year term, your contracted payments per kWh first service the senior debt and then deliver the equity investor a target IRR of around 7–9%. Your covenant strength and the contract term directly affect that cost of capital, and therefore the price per kWh you are offered.

Is a solar PPA off-balance-sheet?

Often, but not automatically. Under IFRS 16 the question is whether the contract conveys the right to control an identified asset. A PPA drafted as a contract to buy electricity — with the SPV retaining operational control — usually sits outside lease accounting and is expensed as you consume power. If the contract effectively gives you control of a dedicated asset, an auditor may identify an embedded lease. Involve your auditors early.

How is PPA financing different from asset finance or a lease?

A PPA transfers both the funding and the performance risk to a third party, and you never own the asset. Asset finance gives you the system for £0 down but you own it (and carry the risk) at the end of the term; an operating lease keeps the asset with the lessor but you still rely on its output. See our PPA vs asset finance and PPA vs operating lease comparisons for the detail.

Does SPPA fund or broker PPAs?

No. We are an independent editorial advisory and matching service, not a funder, installer or FCA-authorised broker. We explain how PPA financing works, set realistic tariff expectations, and introduce off-takers to vetted providers for a disclosed referral fee. The capital always comes from the provider's own funds, never from us.

Related on this site

• /mechanics/structure/ — On-site, sleeved, virtual and corporate — the physical and contractual types
• /mechanics/pricing/ — Benchmark p/kWh tariff bands by system size and structure
• /mechanics/term/ — Why terms run 15–25 years and how it drives the tariff
• /providers/ — The typology of who funds commercial PPAs in the UK
• /compare/ppa-vs-cash/ — Zero-capital financing versus buying the system outright
• /compare/ppa-vs-self-finance/ — Cheaper kWh now versus owning the asset at the end