PPA structures

On-Site, Private Wire and Sleeved Solar PPAs Explained

Last updated 15 October 2026 · Figures indicative

Short answer: An on-site (behind-the-meter) PPA puts solar on your own building; a private wire PPA supplies you by direct cable from a nearby array; a sleeved PPA delivers power from a distant solar farm through your energy supplier, who "sleeves" it onto your bill. On-site suits single sites; sleeved suits large multi-site energy users.

PPA structures compared

UK solar PPA structures (indicative)
	On-site	Private wire	Sleeved	Virtual
Location	Your roof / land	Adjacent land	Remote solar farm	Remote solar farm
Physical delivery	Behind your meter	Dedicated cable	Via public grid	None
Network charges	Avoided	Mostly avoided	Apply	N/A
Typical size	50 kWp–5 MWp	1–20 MWp	5–50 MWp+	10 MWp+
Typical buyer	Single sites	Factories, campuses	Multi-site corporates	Large corporates
Complexity	Low	Medium	High	High

On-site (behind-the-meter) PPA

Solar on your own roof or land feeds your building directly, so every kWh you use avoids the full grid tariff including network charges. The simplest and most common structure — explained in the solar PPA guide.

Private wire PPA

An array on neighbouring land supplies you over a private cable. It needs a wayleave or easement for the cable route and often planning permission for the array, but delivers near on-site economics for sites without enough roof. Common in industrial solar projects.

Sleeved PPA

You contract for output from a specific solar farm; your licensed supplier takes the power onto the grid and "sleeves" it onto your bill, adding balancing and network costs. Gives price certainty on a large volume across many sites, but contracts are complex and usually need a supplier willing to sleeve.

Virtual or financial PPAs

A purely financial contract-for-difference: you agree a strike price with a generator and settle the difference against market prices, while buying power normally. Used by large corporates for price hedging and renewable claims.

Landlord–tenant structures

On multi-let estates, a landlord can sign the PPA (or own the system) and sell power to tenants through sub-metering, or a single tenant can sign with landlord consent. Agree what happens at lease end before installation.

Which is right for you

One site with a good roof → on-site.
Large site with adjacent land → private wire.
Many sites, several GWh a year, no roof space → sleeved.
Corporate hedging and renewable claims → virtual.

PPA structure FAQs

What is the difference between private wire and sleeved PPAs?

A private wire PPA delivers power over a dedicated cable from a nearby solar array straight to your site, avoiding most network charges. A sleeved PPA delivers power from a distant solar farm over the public grid, with your licensed supplier passing it through to your bill, so network and supplier charges still apply.

What size do you need for a sleeved PPA?

Sleeved PPAs usually suit organisations buying several GWh a year, often across multiple sites, because the contracts are complex and the solar farm is typically 5MW or larger. Smaller users can sometimes join through aggregated or supplier-led schemes.

Do off-site PPAs reduce our Scope 2 emissions?

They can reduce market-based Scope 2 emissions if you receive the REGOs for the power. They don't reduce location-based emissions in the way on-site solar does. Check who holds the REGOs in the contract.

Sources

Price ranges for larger systems, running costs, batteries and PPA rates are indicative market ranges from UK installer, funder and market sources; no official series exists above 50kWp.

Not sure which structure fits?

Describe your sites and energy use for personalised guidance.

Get your eligibility guidance