The best energy tariff for plug-in solar

GB average unit rate, Oct–Dec 2026: 26.32 p/kWh
GB average standing charge: 54.83 p/day
regional unit rate range: 25.36–27.86 p

Each kWh your panels supply while you’re using it saves whatever you’d have paid for that kWh at that moment. Export is usually unpaid (see export). Our tariff matcher works out the best fit from your usage pattern. This guide explains the logic.

How does solar work with each tariff type?

Tariff type	What each self-used kWh saves
Single-rate (including the price cap)	The unit rate. Simplest case, and our calculator’s default.
Fixed-price	The fixed unit rate, held for the term. Your saving stays predictable while the cap moves.
Time-of-use (cheaper at night)	The daytime rate only. The cheap overnight hours are covered by the tariff, not the panels.
Half-hourly or wholesale-linked	The price in that half-hour. Enter a rate close to your typical daytime price in the calculator as an estimate.

For October–December 2026, Ofgem’s GB average cap is 26.32p/kWh for Direct Debit customers (Ofgem). That reflects VAT on electricity being cut from 5% to 0% from 1 October 2026 to 31 March 2027 (Ofgem).

On a time-of-use tariff, compare its daytime rate with the cap: the higher it is, the more each self-used kWh is worth.

Solar doesn’t touch the standing charge. It’s a daily charge whatever you use: 54.83p a day on the October–December 2026 GB average cap.

Does where you live change the saving?

Yes. The price cap differs by region, so the same kit with the same self-use saves different amounts. Worked for 448 kWh a year used at home (our 0.88 kWp reference kit in London at 35° south, medium daytime use):

Region (Ofgem)	Unit rate, Oct–Dec 2026	Yearly saving
East Midlands	25.36p	£114
GB average	26.32p	£118
London	26.60p	£119
South Eastern England	26.88p	£121
Merseyside and Northern Wales	27.86p	£125

The calculator uses your region’s rate automatically from your postcode.

Can you get paid for export?

For most plug-in owners, no:

The Smart Export Guarantee needs an MCS-certified installation and a half-hourly export meter (gov.uk), which a self-fitted kit won’t have. DESNZ’s impact assessment leaves export out of its savings figures for this reason.
Octopus says customers who buy an Octopus plug-in kit and get their electricity from Octopus are eligible for its “Outgoing Prime” export tariff. If you bought your kit elsewhere, Octopus says “You won’t be able to sign up for an Octopus export tariff for that system” (Octopus).

What we couldn't confirm

We haven’t confirmed the Outgoing Prime rate. Other suppliers’ plug-in export offers are also unconfirmed. Don’t choose a tariff for its export rate unless the supplier has confirmed in writing that your kit qualifies.

How do you get more from any tariff?

Whatever you’re on, the best lever is using more of your own output. For a two-panel kit in London at 35° south, at 26.32p:

Daytime use	Share of output used at home	Yearly saving
Low (about 100 W steady)	33%	£78
Medium (about 170 W)	50%	£118
High (about 240 W)	63%	£149

Ways to move up a band:

Run the washing machine, dishwasher and tumble dryer in the middle of the day, using delay timers if you’re out.
Charge laptops, tools and e-bike batteries in daylight.
If you’re out all day and use little in daylight, consider a single-panel kit (see 400 W vs 800 W).

Plug-in batteries are outside the rules

A battery would let you use the surplus in the evening, but grid-connected plug-in batteries are outside the GB rules. See batteries.

Should you switch tariff because of solar?

Usually not on its own. Most of your electricity will still come from the grid: DESNZ says a kit can provide “up to 20% of an average home’s electricity use” (press release). Choose your tariff on your whole usage pattern, with solar as one input.

What to do next

Compare tariffs against your usage in the tariff matcher, then check your kit’s figures in the calculator.