On-site PPA vs Sleeved PPA
Both call themselves PPA but very different — on-site builds on your roof, sleeved gets power from a generator elsewhere via a supplier. Trade-offs.
Quick answer: On-site PPA or Sleeved PPA?
On-site PPA vs Sleeved PPA: On-site is cheaper per kWh and lower risk but limited to a single site. Sleeved suits multi-site businesses and tenants without roof rights.
Side-by-side comparison
| On-site PPA | Sleeved PPA | |
|---|---|---|
| Generation location | Your roof / land | Elsewhere (solar farm, third-party rooftop) |
| Delivery mechanism | Direct via your kit | Via electricity supplier 'sleeving' |
| Supplier role | None | Critical — supplier must agree to sleeve |
| Tariff (year 1) | 9-18 p/kWh | 11-20 p/kWh (excludes supplier markup) |
| Best for | Single-site businesses with roof | Tenants, multi-site, no roof rights |
| Site survey needed | Yes | No (generator pre-built) |
| Build time | 6-16 weeks | 0 — already built |
Our verdict
On-site is cheaper per kWh and lower risk but limited to a single site. Sleeved suits multi-site businesses and tenants without roof rights.
Same name, different electrons
Both structures are sold as "a PPA", but the power comes from opposite places. An on-site PPA generates on your own roof or land and feeds your building directly through your own connection — no supplier involved. A sleeved PPA draws from a solar farm or third-party rooftop somewhere else entirely, and your electricity supplier "sleeves" that generation through to your meter. That single difference cascades into cost, risk and who else has to say yes.
Price, and the supplier in the middle
On-site typically prices lower — roughly 9–18p/kWh in year one — because nothing sits between generator and load. Sleeved deals run higher, around 11–20p before the supplier's markup, and they hinge on a willing supplier: no supplier agreement, no sleeve. That extra counterparty is the sleeved model's biggest single point of fragility, and it's worth confirming early with prospective PPA providers and suppliers.
Which one your situation allows
- Own a single site with a sound roof? On-site is cheaper and simpler — expect a survey and a 6–16 week build.
- Lease your premises, lack roof rights, or run many small sites? Sleeved works where on-site can't, with effectively zero build time because the generator already exists.
The honest summary
On-site wins on price and risk when you have a roof and a single site to serve. Sleeved unlocks a PPA for tenants and multi-site operators who'd otherwise be shut out. See both set against the other funding routes in the comparison hub, then walk through how each structure delivers power.
Comparison FAQs
Which option should I pick?
On-site is cheaper per kWh and lower risk but limited to a single site. Sleeved suits multi-site businesses and tenants without roof rights. Run your specific numbers in our PPA calculator before deciding.
Can the two be combined?
Sometimes. SEG income always layers on top of either route. Capital allowances combine only with cash or self-finance — and note solar is a special-rate asset, so it does NOT qualify for full expensing; the correct 100% route is the Annual Investment Allowance (up to £1m/year). PPA + grant rarely stack — most grants exclude PPA structures.
Where can I read more about the underlying mechanics?
Our mechanics hub covers 10 deep-dives on PPA structure, pricing, escalators, term, end-of-contract, off-taker covenant, EPC, O&M and M&V.
Want to model your specific site?
Our calculator runs both scenarios with your actual kWh, tariff and site assumptions.
Open calculatorFor the mechanism in isolation rather than the head-to-head, the sleeved PPA page covers the supplier's role, the imbalance risk and who carries it.
The on-site option in this comparison is more precisely a behind-the-meter PPA, priced against what you consume rather than what you export.
If you have already ruled out off-site supply, go straight to the on site PPA mechanism and its roof-lease requirements.
Sleeving is only one way to buy power from a generator elsewhere; virtual and private-wire deals are covered under off-site PPAs more broadly.
Request an indicative tariff for this site type
On-site PPA vs Sleeved PPA — tell us about your site and we'll return an indicative p/kWh tariff for it. Reply by email within one working day.