The solar PPA process: seven steps from quote to switch-on
Signing a solar PPA is a sequence of seven steps, from an indicative tariff to the choices at the end of the term. This page sets out what happens at each step, who leads it, what you need to provide, and the documents you sign along the way.
Indicative tariff
Provider reviews your annual kWh consumption, roof area, postcode irradiation, and DNO context. Returns an indicative p/kWh band and term length within 1–2 weeks.
Site survey
Provider's EPC contractor surveys roof structure, electrical infrastructure, planning constraints and DNO connection capacity (G99/G100 if >50kWp).
Heads of Terms
Non-binding term sheet covers system size, tariff, escalator, term, off-taker covenant requirements, exit options and assignment-on-sale clauses.
Full contract
Long-form PPA executes alongside the EPC contract and (if applicable) the O&M agreement. Typical legal cost £8k–£25k for the off-taker.
Build
EPC contractor installs the system over 6–16 weeks depending on size. DNO connection, commissioning and Ofgem MCS certification follow.
Operations
From day one of commissioning you pay the PPA tariff for every kWh generated. Provider handles O&M, insurance, monitoring, REGO administration and SEG export (where structured).
End-of-term
After 15–25 years you typically have three options: (a) extend at a re-negotiated tariff, (b) buy the system at fair market value, or (c) have the provider remove the system at no cost to you.
Who does what at each step
The process is short on your side and long on the provider's: most of the work between heads of terms and switch-on is the provider's contractor, its funder and the network operator. What you control is the information you provide and how quickly your side signs.
| Step | Who leads it | What you provide |
|---|---|---|
| Indicative tariff | You and the provider (or a matching service) | Annual consumption, ideally half-hourly data; the roof or land you have in mind; your postcode |
| Site survey | The provider's installer | Access, roof drawings, electrical single-line diagrams, any structural reports |
| Heads of terms | The provider | Agreement on tariff, escalator, term, exit routes — and your latest accounts for the credit check |
| Full contract | Both sides' lawyers | Legal review of the PPA and the roof licence or lease; landlord consent if you rent |
| Build | The installer, and the network operator for the connection | Site access and a named contact; any shutdown windows for the electrical tie-in |
| Operations | The provider (operation, maintenance, insurance) | Paying for the units the array supplies; meter access |
| End of term | You decide | A choice to extend, buy or have the system removed |
The documents you sign — and the ones you don't
On a third-party PPA you normally sign two things: the PPA itself, which sets the tariff and the terms of supply, and a roof licence or lease, which gives the provider the right to keep its system on your building for the term. You may also be asked to sign a direct agreement with the provider's lenders, giving them step-in rights if the provider fails.
Everything else sits on the provider's side of the table: the engineering, procurement and construction (EPC) contract with the installer, the operation and maintenance agreement, the grid connection agreement with the network operator, and the finance documents behind the asset. You do not need to sign them — but it is worth asking who the installer is, and whether its warranties pass to you if you buy the system later.
Where the process usually stalls
Most delays come from the same five places, and all of them can be started early:
- The roof. A roof near the end of its life has to be replaced first, because it cannot be re-covered cheaply once an array sits on it for two decades.
- The grid connection. Larger systems need an application to the local network operator, and constrained networks can mean studies, upgrades or export limits.
- Credit approval. The funder is lending against your payments, so it reviews your accounts — a parent guarantee or a shorter term can unlock a weaker covenant.
- Landlord consent. Tenants need the landlord's written consent, and the lease has to outlast the PPA or pass to the next occupier.
- Legal review. Deemed generation, exit prices and roof-works clauses are where negotiations slow down; agree the principles at heads of terms, not in the final draft.
Once the system is running, the question becomes what a solar power purchase agreement actually saves you — our guide to the PPA tariff covers what you pay and what else the contract can charge.
Common questions about the solar PPA process
How long does it take to sign a PPA?
From first call to commissioning typically 6–12 months: 2–4 weeks for an indicative tariff, 4–8 weeks for site survey and term sheet, 8–12 weeks for full contract negotiation, 6–16 weeks for build.
Do I need to pay anything upfront?
No. The provider funds 100% of the system. Your only upfront costs are typically £8k–£25k of legal review on the long-form contract for a mid-size deal.
Can I terminate early?
Most PPAs include termination clauses but with a buy-out at fair market value or a discounted cashflow of remaining payments. Early termination is rarely cheap; structure the term carefully upfront.
What if I sell the building?
Standard contracts include change-of-control and assignment-on-sale clauses. The buyer typically inherits the PPA, but conditions apply — particularly on covenant rating.
Who owns the panels?
The PPA provider (or the SPV behind it) owns the system for the duration. At end-of-term you can buy, extend or have the panels removed.
What documents do I sign for a solar PPA?
Normally two: the PPA, which sets the tariff and supply terms, and a roof licence or lease giving the provider the right to keep its system on your building. You may also sign a direct agreement with the provider's lenders. The installation, maintenance, grid connection and finance contracts sit with the provider.
Want to see what tariff your site qualifies for?
A 60-second form gives us enough to return an indicative p/kWh band, term length and provider shortlist within one working day.
Get an indicative PPA tariffWhere the generator and the site sit on different grid connections, the power is contracted through a licensed supplier instead of a private wire, and a sleeved PPA is the structure that does it.
Not every agreement moves electrons to your meter at all: a virtual PPA settles the difference between a strike price and the market reference price, leaving your existing supply contract untouched.
Buyers taking volume from a dedicated generating asset rather than a supplier's blended tariff are in corporate territory, and a corporate PPA sets out the covenant and certificate questions that follow.
The simplest version keeps everything behind one connection — an on-site PPA puts the array on your own roof or land and sells you what it produces.
The unit rate in year one is rarely the rate you pay in year ten, because most contracts carry either a fixed uplift or a CPI escalator that tracks inflation.
If you are earlier in the decision, start with what a solar PPA is and whether it suits your site before working through the process.
See what PPA providers would quote you
The solar PPA process: seven steps from quote to switch-on — tell us about your site and we'll return an indicative p/kWh tariff for it. Reply by email within one working day.