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

When On-site PPA wins

On-site PPA typically wins when (a) you need zero upfront capital, (b) you want operations and performance risk transferred, (c) your business horizon doesn't extend to a 25-year capital commitment, or (d) you want speed to deploy.

When Sleeved PPA wins

Sleeved PPA typically wins when (a) you have capital and want the lowest 25-year cost, (b) you want to retain ownership of the asset and its long-term value, (c) you can manage operations in-house, or (d) you're constrained by structural reasons (e.g., procurement rules for public bodies).

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. AIA / Full Expensing combine only with cash or self-finance. 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.