By the PPA Funding team Last updated
A private wire is a direct cable that carries electricity from an on-site or neighbouring generator to a consumer without using the public distribution network. It lets a solar array feed a nearby factory or a campus building directly, often at a lower delivered cost because certain grid charges are reduced or avoided.
What is a private wire supply?
A private wire is a cable that runs directly from a generator to the site that uses the power, bypassing the public grid. The classic case is a ground-mounted solar array or rooftop system connected straight to the factory, warehouse or campus next door, so the electricity never travels through the distribution network.
Because the power stays off the public network, some of the charges bundled into a normal electricity bill, such as distribution and certain policy costs, may not apply to the units delivered over the wire. Any building still keeps a normal grid connection for the times generation cannot cover demand.
Where does a private wire make sense?
Private wire arrangements suit a large, steady electricity user sitting close to where the power is generated. Business parks, single-owner campuses, manufacturing sites with spare adjacent land, and estates where one landlord controls several buildings are typical candidates, because the generator and the load are near each other and under aligned control.
The greater the share of generation the site can use directly, the stronger the case. A user that runs through the day matches solar output well. If the two parties are different legal entities, or the cable crosses land or a public road, the arrangement needs careful contracts and the right permissions.
What should a business check before committing?
A private wire adds engineering and legal steps that a standard rooftop connection avoids. You will need wayleaves or easements if the cable crosses third-party land, a metering setup that measures private-wire and grid supply separately, and clarity on who owns and maintains the cable over its life.
The regulatory position around private networks can be involved, and the treatment of network charges is set by rules that change, so confirm the current position with a qualified adviser before relying on any saving. As an introducer we can connect you to funders and installers who structure these projects, including under a PPA where a funder owns the generation.
This guide is general information, not financial or tax advice. Your circumstances determine what applies — please confirm with your accountant or advisor. Get a tailored proposal →
Frequently asked questions
Is a private wire the same as being off-grid?
No. A site on a private wire almost always keeps its normal grid connection as back-up for when the on-site generator cannot meet demand, such as at night. The private wire supplies power directly when it can, and the grid fills the gap.
Can a private wire be funded through a PPA?
Yes, this is a common structure. A funder owns and pays for the generation, then sells the electricity to the nearby user over the private wire at a fixed rate, guaranteed at least 30% below the grid, with the system passing to the user for £1 at the end of the term.
Related guides
- Can my business get free solar panels? What “free solar” really means
- What does “£0 upfront” commercial solar actually mean?
- Does solar qualify for the 40% first-year allowance?
See our funding options, commercial solar and solar by industry pages.