Comparison

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.

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

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.

FAQs

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.