Time-of-Use Tariffs Solar UK: Economy 7 and Smart Charging

The UK electricity market has changed sharply in the past two years. Standard variable tariffs still follow the Ofgem price cap — 24.67p/kWh for Q2 2026 — but a growing range of time-of-use (TOU) tariffs let you pay much less at certain times and sometimes earn more when exporting. For solar owners, pairing the right tariff with your system can meaningfully cut bills. This guide explains each major option and tells you which fits solar-only, solar plus battery, and solar plus EV setups.

What is a time-of-use tariff?

A TOU tariff charges different unit rates depending on the time of day. Off-peak windows — typically overnight when grid demand is low — carry cheaper rates. Peak windows (usually late afternoon into early evening) carry higher rates. The logic for solar owners is straightforward: your panels generate most electricity at midday when you are often out, so you already avoid buying at the peak; a TOU tariff then lets you top up a battery or charge an EV at the cheapest overnight rate, maximising what you generate and minimise what you spend.

All dynamic TOU tariffs require a working smart meter. Ofgem's market-wide half-hourly settlement rollout, which progressed through 2025–2026, now provides the billing infrastructure — but you still need a SMETS2 meter (or an upgraded SMETS1) to access these tariffs. Suppliers are obliged to install one free of charge if you request it.

Economy 7 — the original off-peak tariff

Economy 7 gives you seven cheap hours overnight, typically between midnight and 7 am (exact timing varies by region and supplier). Current overnight rates sit roughly between 11p and 13p/kWh depending on supplier and region; the cheapest available in June 2026 was around 11.14p/kWh from E.ON Next. The daytime rate is higher than a standard tariff to compensate, so Economy 7 only saves money if a meaningful share of your consumption falls in those seven hours.

For solar owners Economy 7 is most useful as a foundation for overnight battery charging — fill the battery cheaply at night, run the house off solar during the day, and draw on the battery in the evening before switching back to the cheap overnight window again. Storage heaters, dishwashers, and washing machines on timers also suit Economy 7 well. The downside is that standing charges are often slightly higher than a standard rate, and the on-peak daytime rate can exceed 30p/kWh with some suppliers, so households that cannot shift enough consumption will end up worse off.

Economy 10 — more windows, but declining

Economy 10 offers ten cheap hours split across three windows — a longer overnight block plus an afternoon and an evening slot. The extra windows suit properties with high electric heating loads (large storage heaters, electric boilers) where more off-peak flexibility is genuinely useful. However, Economy 10 is not expanding: the Radio Teleswitch Service that controlled many legacy Economy 10 meters was switched off on 30 June 2025, and Ofgem required suppliers to migrate those customers to smart meters or standard tariffs. In 2026 Economy 10 is a legacy product — check availability with your supplier but do not expect it to be the long-term choice.

Agile Octopus — half-hourly wholesale pricing

Agile Octopus sets a new price every 30 minutes, tracking the UK wholesale electricity market. Rates can fall to near-zero or go negative on windy nights when renewable output floods the grid; conversely, a 4–7 pm peak uplift can push prices well above the cap average. The tariff is capped at around 100p/kWh in extreme conditions.

Agile suits solar owners who have a smart battery system that can respond to real-time prices — charging when the rate drops below, say, 5p/kWh and holding that charge for the evening peak. Compatible systems from inverter manufacturers such as GivEnergy (noting its administration in April 2026; check continuity of service), Solis, SolarEdge, and others can pull Agile pricing via API and dispatch automatically. Without automation the tariff is harder to manage: watching 30-minute slots manually is impractical. Households that actively shift flexible loads — EV charging, dishwasher, washing machine — and use automation typically reduce bills by 10–25% annually. A working SMETS2 smart meter with half-hourly data sharing enabled is required.

Intelligent Octopus Go — predictable overnight rate

Intelligent Octopus Go gives a fixed low rate between 23:30 and 05:30, currently around 7–7.5p/kWh depending on region (Octopus cut rates in April 2026). Outside that window you pay the standard Octopus Go day rate, which sits broadly at the price cap level. The tariff was designed primarily for EVs: it communicates with compatible smart chargers and vehicles to start charging automatically in the cheap window, but the overnight rate applies to all consumption in the home during those six hours, including a battery system charging from the grid.

Intelligent Octopus Go is the most predictable TOU tariff in the current market. The fixed overnight window makes scheduling trivial — set your battery or EV charger to run from 23:30 — and the saving is known in advance. For a solar household with a 10 kWh battery fully charged overnight at 7p/kWh instead of the 24.67p cap rate, the overnight charge alone saves roughly £1.77 per cycle. Multiply by 300 charging nights and the annual saving is around £530 from grid charging alone, before counting the solar generation on top. See our guide to home battery storage for a full cost breakdown.

Octopus Flux — import and export both track wholesale

Flux links both your import rate and your export rate to the wholesale market, with three tiers: an off-peak import window (2–5 am, cheapest), a shoulder period for the rest of the day, and a peak window (4–7 pm, most expensive to import but most valuable to export). The design favours battery arbitrage: charge cheaply overnight, export during the peak, and earn more per kWh exported than the flat SEG rates offer.

Flux is available to solar owners with a compatible battery inverter. Note that standard Flux has faced availability gaps due to wholesale price volatility — check the Octopus website for current sign-up status. For a household with a 4.9 kWp array and a 5.2 kWh battery, Octopus estimates annual savings of around £937 (£402 from grid export plus £535 from reduced import). The Smart Export Guarantee still underpins all export payments; learn more in our SEG rates guide.

Which tariff suits your setup?

Solar only (no battery, no EV)

Your midday solar output already offsets the most expensive import window. A TOU tariff adds value only if you can shift significant loads to an off-peak window — running a dishwasher or washing machine overnight, for example. Economy 7 is the simplest option; Agile may save more if you are willing to use scheduling automations. Without a battery or EV to absorb the cheap overnight electricity, the gains are modest.

Solar plus battery

A battery unlocks the full value of TOU tariffs. The recommended pairing depends on preference: Intelligent Octopus Go for simplicity (fixed 23:30–05:30 window, easy to schedule), Agile Octopus for maximum flexibility (automated dispatch chasing the cheapest 30-minute slots), or Flux if your inverter supports it and you want to earn more on exports during the evening peak. Economy 7 works with any battery inverter and is the safest starting point if your system is older or does not support API integration.

Solar plus EV

Intelligent Octopus Go was built for this combination. It communicates with compatible chargers and vehicles to start charging automatically in the cheap window, applying the low overnight rate to both car and battery. If your EV charger is not on the Intelligent Octopus compatible list, standard Go or Economy 7 still let you timer-charge at a known cheap rate. For a full list of compatible chargers, see our home EV charger guide.

Smart meter: the one requirement all TOU tariffs share

Every dynamic TOU tariff — Agile, Intelligent Go, Flux — requires a SMETS2 smart meter with half-hourly data sharing enabled. Economy 7 can work with older two-register meters, but tougher Ofgem rules from February 2026 pushed suppliers to migrate legacy Economy 7 customers to smart meters as part of the RTS switch-off programme. If you do not yet have a smart meter, ask your supplier — installation is free and usually completed within a few weeks. Over 30 million smart meters were installed across Great Britain by early 2026, so rollout is well advanced.

Once your smart meter is active, switching between TOU tariffs is usually a digital process with no new hardware required. Some tariffs (Agile, Flux) also need your inverter or battery system to have API access; check with your installer that the system firmware supports the tariff's scheduling protocol before switching.