The best smart tariffs for solar, batteries and EVs
A standard energy tariff charges the same price all day. A smart, or time-of-use, tariff charges different prices at different times, which is exactly what a home with solar, a battery or an EV can take advantage of. Pick the right one and you buy power cheaply overnight, sell or avoid it when it's expensive, and turn your kit into a money-saver rather than a fixed cost. This guide explains the types that matter and how to match one to what you've got.
How a smart tariff works
Smart tariffs price electricity by the half-hour or by set windows, following the wholesale market. The pattern is usually the same: power is cheap overnight when demand is low, and dear in the early evening peak. If you can move your big loads, charging a car, filling a battery, running the dishwasher, into the cheap windows, you pay far less than someone on a flat rate. You need a working smart meter for any of these, since the supplier has to read your usage by the half-hour.
The two halves: import and export
Solar owners have two tariffs to think about, not one. The import tariff is what you pay for power you buy; the export tariff is what you're paid for power you send back under the Smart Export Guarantee. The best overall deal balances both, and they don't always come from the same supplier.
| Tariff type | What it does | Best for |
|---|---|---|
| EV / off-peak import | Cheap overnight window (~7p for 5 to 6 hours) | EVs and batteries |
| Dynamic / half-hourly import | Price changes every half-hour with the market | Hands-on users who can shift load |
| Solar / flux-style | Cheap night, high-value evening export window | Solar plus battery |
| Fixed export (SEG) | A set price per exported unit | Predictable export income |
| Variable export | Export price tracks demand, can spike | Batteries that can target peaks |
Match the tariff to your kit
If you have solar only
Your priority is a strong export rate, because without storage you'll send a fair share of summer generation back to the grid. Export rates range from about 12p to 20p depending on supplier, so this is worth shopping around. Pair it with a reasonable flat or off-peak import rate. The export side is explained fully in how the Smart Export Guarantee works, and the effect on returns in solar panel payback.
If you have solar and a battery
Now a cheap overnight window earns its keep: charge the battery from the grid at night, run the house on it through the evening peak, and let solar refill it by day. That arbitrage is a big part of why storage pays on the right tariff, as covered in are solar batteries worth it. Look for a tariff that combines a low night rate with a decent export price.
If you have an EV
A dedicated EV tariff with a cheap five-to-six-hour overnight window is usually the single best money-saver in the house, since charging is your biggest movable load. The full charging picture is in EV charging at home. Some EV tariffs schedule charging for you around the cheapest half-hours.
What to check before you switch
- You have a working smart meter. Time-of-use tariffs need half-hourly readings, so a SMETS2 smart meter is a prerequisite.
- The standing charge, not just the unit rate. A headline-cheap overnight rate can be undercut by a high daily standing charge.
- The peak rate. Off-peak windows are paid for with a dearer peak. If you can't avoid using power at peak, the maths weakens.
- Whether import and export must be with the same supplier. Some require it, some don't. Splitting them can beat a single bundle.
- Exit fees and rate changes. Smart tariff rates move; check how often and whether you're tied in.
The detail most people miss
The best tariff is the one that fits your pattern, not the one with the lowest single number. A cheap overnight rate is worth little if you can't shift load into the night; a high export rate matters more the less you self-consume. Map your own daily usage first, then pick the tariff that rewards it. This is the same logic that decides whether a battery pays at all.
Frequently asked questions
An energy tariff that charges different prices at different times of day, usually cheap overnight and dear at the early-evening peak, so you save by shifting usage to the cheap windows.
For solar alone, prioritise a high export rate (around 12 to 20p) with a reasonable import rate. With a battery, add a cheap overnight window so you can charge cheaply and avoid peak prices.
Yes. Time-of-use and EV tariffs price by the half-hour, so a working smart meter is required.
Sometimes. Some suppliers require both with them; others let you mix. Splitting can occasionally beat a single bundled deal, so it's worth comparing.
It changes, but the highest fixed Smart Export Guarantee rates reach about 20p, while variable export tariffs can pay more at peak times if you have a battery to target them.