The best tariff for solar & battery storage is worth more than the right panel.
A solar and battery system earns its money twice: once on what you stop buying, and once on what you sell back. Which tariff you’re on decides how big both of those are, and it is the one part of the whole job you can change any time, for free.
How a smart tariff pays you
Three things decide whether switching is worth it. None of them is the advertised rate.
The gap is the whole game
You buy electricity at one price and get paid another for what you export. A flat tariff makes that gap small and fixed. A smart tariff widens it, cheap overnight import, high-value export at teatime, and a battery is what lets you sit on the right side of it.
A battery turns a tariff into money
Without storage you export whenever the sun happens to shine and import whenever you happen to need power, you have no control over timing, so a time-of-use tariff can only hurt. With storage you choose, which is the point.
Match the tariff to your life, not the headline
The cheapest overnight rate is worthless if your battery is too small to fill in the window. The best export rate is worthless if you're out all day and export anyway. Size first, then tariff.
Savings Calculator
See How Much You Could Save
Energy prices keep climbing. Estimate what solar & battery could put back in your pocket over the years.
Solar Savings Calculator
See how much you could save by generating your own energy
Solar + battery typically covers 70–100%
UK prices averaged 10%+ from 2022–2024
Total saved, year by year
Hover the chart for any yearShow year-by-year savings ↓Hide breakdown ↑
| Year | Bill Without Solar | You Pay | Saved | Total Saved |
|---|---|---|---|---|
| 1 | £1,980 | £594 | £1,386 | £1,386 |
| 2 | £2,178 | £653 | £1,525 | £2,911 |
| 3 | £2,396 | £719 | £1,677 | £4,588 |
| 4 | £2,635 | £791 | £1,845 | £6,432 |
| 5 | £2,899 | £870 | £2,029 | £8,462 |
| 6 | £3,189 | £957 | £2,232 | £10,694 |
| 7 | £3,508 | £1,052 | £2,455 | £13,149 |
| 8 | £3,858 | £1,158 | £2,701 | £15,850 |
| 9 | £4,244 | £1,273 | £2,971 | £18,821 |
| 10 | £4,669 | £1,401 | £3,268 | £22,089 |
Over the next 10 years you could save around £22,089 , money that would otherwise go straight to the energy companies. Generate it, store it, own it.
The tariffs worth knowing
What each one is built to do, who it suits and where it bites. We haven’t printed rates: they move constantly, and a number on a page like this is out of date within weeks. Follow the link for the supplier’s current figures.
Octopus Flux
Octopus Energy
Closed to new customers since spring 2026, check before you plan around it.
Current rates- How it works
- Three import rates and three export rates across the day, built specifically around a home battery, cheapest overnight, most valuable export in the late-afternoon peak.
- Suits
- Solar with a battery big enough to hold a full evening, where you want the export side working as hard as the import side.
- Watch for
- Needs a compatible battery and a smart meter. Import at peak is expensive if you get the schedule wrong.
- How it works
- Prices change every half hour, following the wholesale market, published the afternoon before. Occasionally goes negative, you are paid to use power.
- Suits
- People who automate. If your battery and EV charger can follow a price signal without you thinking about it, this has the most headroom of anything here.
- Watch for
- No price certainty. Winter peaks can be very expensive, and it rewards attention, or good automation, rather than set-and-forget.
- How it works
- Two rates: a cheap overnight window and a flat rate the rest of the day. The simplest smart tariff on this list.
- Suits
- EV owners, and anyone who wants the battery filled cheaply overnight without managing anything.
- Watch for
- The cheap window is short, so a large battery may not fill in one night. Daytime rate is higher than a standard fixed tariff.
- How it works
- Two rates with a notably long overnight window, more hours of cheap import than most EV tariffs offer.
- Suits
- Larger batteries, or two cars, where the limit is how many hours of cheap rate you can get rather than the rate itself.
- Watch for
- The daytime rate and the export side are generally less competitive. Check exit terms before switching.
- How it works
- Two rates with a multi-hour overnight window, from a supplier that also offers fixed-price options.
- Suits
- Households who want a cheap overnight rate but would rather not be on a market-following tariff.
- Watch for
- Peak rates are high, and it needs a working smart meter and the right meter configuration.
Tariff availability checked 24 September 2026. Suppliers open and close tariffs without much notice, always confirm on the supplier’s own page before switching. Eco2u is not an energy supplier and cannot switch you; we install the system that makes a smart tariff worth being on.
Which one suits your setup
Solar and a battery, no EV
You want the export side earning as well as the import side cheap. A three-rate battery tariff is the natural fit where one is open to you; where it isn't, a good fixed export rate alongside a cheap overnight import window is the sensible fallback.
Solar, a battery and an EV
The car is the biggest single load in the house, so the overnight window matters more than the export rate. A simple two-rate EV tariff usually beats a clever one, because you'll fill the car and the battery in the same window.
You'll automate it
If you're happy for the system to follow half-hourly prices, a market-following tariff has the most upside of anything here, and the most variance. It rewards a battery that can be scheduled properly.
Size the battery first
Every tariff on this page rewards storage, and how much storage decides which one is worth being on. That is the part we can actually help with, the survey works out what your house uses and when, and the battery gets sized to it.