Private wire is a direct cable from a solar farm (or other generator) to a business, so the power doesn’t travel over the public grid. Because it skips the grid, both sides can share the savings on network charges.
How it works
- A solar farm is built near your site. Often on land next door, or within a short cable run.
- A private cable connects them. Power flows straight from the solar farm to your site.
- You buy that power under a contract, usually at a lower price than grid electricity.
- You keep your grid supply. When the solar farm isn’t producing enough, you buy top-up power from your normal supplier. The solar farm usually keeps its own grid connection to export any surplus.
Why do it?
- Lower bills. Power that doesn’t use the public network avoids some network and policy charges.
- Better income for the generator. The solar farm can earn more than it would selling to the wholesale market.
- A visible green supply. You can see where your power comes from.
The rules, in brief
In Great Britain you need a licence, or an exemption, to generate, distribute or supply electricity. Most private wire schemes rely on exemptions in the Electricity (Class Exemptions from the Requirement for a Licence) Order 2001. In short:
- Generation: stations up to 10MW (or up to 50MW in some cases) don’t need a generation licence.
- Distribution: a private network supplying business (non-domestic) customers can be exempt, with no size limit.
- Supply: supplying your own generated power to customers over a private wire can be exempt.
Exemptions apply automatically, but it’s up to the operator to check they qualify. Take legal advice on any scheme.
What to watch
- One customer. The solar farm relies on a single buyer. If that business closes or moves, the income is at risk.
- Long contracts. Private wire usually needs a long-term agreement.
- Credit. The buyer needs to be financially strong.
- Rule changes. Changes to how network charges work can shrink the savings.
- Land and planning. You need suitable land close by, and consent for the solar farm and the cable route.
Who is it for?
Large electricity users with land nearby: factories, cold stores, food processors, data centres, hospitals and big farm businesses. If there’s no room for a solar farm next door, an on-site solar PPA may suit you better.
What we do
We look at your site, your power use and the land and grid around you, and tell you honestly if private wire could work, delivered with our partners. Get a quote →
Sources
- legislation.gov.uk: Class Exemptions Order 2001
- Walker Morris: private wire PPAs in brief
- Local Energy Scotland: non-commodity costs
Correct at the time of writing (1 October 2026). This is general guidance, not legal advice.