What Economy 7 actually is
Economy 7 is a two-rate electricity tariff. For about seven hours overnight you pay a cheaper unit rate. For the other 17 hours you pay a higher peak rate. The cheap window is set by your region and meter, not by you. Common patterns are midnight to 7am, or 12:30am to 7:30am. Some areas put part of the cheap block in the afternoon. Check the times printed on your bill or ask your supplier. Do not guess.
It was designed for night storage heaters and immersion cylinders. Millions of UK homes still sit on it, often on a traditional dual-rate meter rather than a smart meter. That is why it keeps showing up in battery adverts. The overnight hours look, at first glance, like a ready-made charging window.
Economy 7 is not a smart tariff. The clock is fixed. There is no half-hourly price, no app schedule, and no need for a smart meter. A battery on Economy 7 is a timer job: charge in the cheap block, stop when the pack is full, discharge through the day.
How a battery uses the cheap window
The logic is the same as on Octopus Go. You buy electricity when it is cheap, store it, and use it later instead of importing at the expensive rate. No solar required. The battery sits on the house side of the meter and covers whatever load is running, up to its inverter limit, until the stored energy is gone.
A 5 kWh all-in-one with the inverter in the box, wired under G98, typically charges at under 3.68 kW. Filling 5 kWh at that rate takes well under two hours. Economy 7 gives you about seven. That is the opposite of a squeeze. You can charge the battery and still have cheap hours left for an immersion heater, storage heaters, or an EV if you have one.
Round-trip losses are real. A useful working figure is that you get a bit under 5 kWh back out for 5 kWh in, often around 4.5 kWh usable if the pack cycles fully. Treat that as an estimate. It depends on the unit, the temperature, and how hard you run it.
The maths: Economy 7 vs Octopus Go
These are estimates, not a quote. Rates move by region and by supplier, and your usage will not match anyone else's. The Go figures below match what Habo publishes elsewhere on the site. The Economy 7 figures use the typical rates already used on our best tariffs for battery storage page (about 14p off-peak, about 30p peak). Check your own bill before you treat any row as yours.
| Economy 7 (typical) | Octopus Go (typical, 2026) | |
|---|---|---|
| Cheap window | About 7 hours, times vary by region | 5 hours, usually 00:30 to 05:30 |
| Off-peak rate | About 14p/kWh | About 9.5p/kWh |
| Peak rate | About 30p/kWh | About 32p to 35p/kWh, varies by region |
| Spread (the bit a battery captures) | About 16p/kWh | About 23p/kWh |
| Smart meter needed? | No, dual-rate meter is enough | Yes, half-hourly smart meter |
| 5 kWh battery, one cycle a day (estimate) | About £200 to £260/year | About £300 to £360/year |
| Payback on a Habo 5 kWh at £2,499 (estimate) | About 10 to 12 years | About 7 to 8 years |
How the Economy 7 estimate is built: take about 4.5 kWh usable per day, a 16p spread, and most days of the year. That is 4.5 × £0.16 × 365, which is about £260 before you allow for days the pack does not cycle fully. Rounding down to a £200 to £260 band is more honest than pretending every household hits the theoretical ceiling. The Go band of £300 to £360 is the figure Habo uses across the site for the same 5 kWh, one-cycle-a-day case.
Two extra wrinkles, both important:
- The rest of the bill still sits on the peak rate. Economy 7 peak is often higher than a normal single-rate tariff. If the battery only covers part of your daytime use, the leftover kilowatt-hours can be expensive. A battery improves the shifted units. It does not rewrite the tariff for everything else.
- Storage-heater homes are a different case. If most of your electricity already runs overnight (heaters, immersion, maybe an EV), Economy 7 can still be the right household tariff. The battery then covers the leftover daytime load, which is the expensive slice. That is a good fit. If you have gas heating and most of your electricity is daytime cooking, laundry and evening TV, Economy 7 without a cheap smart tariff is often a poor whole-home deal even with a battery.
Rule of thumb. A battery makes Economy 7 more useful. It rarely makes Economy 7 better than a cheap overnight smart tariff. If you can get a working smart meter and move to Go (or a similar off-peak tariff), the battery usually earns more. If you cannot, Economy 7 plus a wired 5 kWh pack is still a coherent setup.
Stay on Economy 7, or switch?
This is the decision that actually matters, and it is not only about the battery.
Stay on Economy 7 if you have night storage heaters that still do the heating, a working dual-rate meter, and a supplier who will not move you without a fight. Add the battery, set the charge window to the cheap block, and let it cover daytime base load. You do not need to wait for a smart meter to start saving on the shifted kilowatt-hours.
Switch to a cheap overnight smart tariff if you can. Octopus Go is the one most UK battery owners use. Typical 2026 figures are about 9.5p for five hours overnight and a much higher daytime rate, with a working smart meter. Go is sold as an EV tariff. In practice the cheap rate applies to the whole house, which is why a home battery likes it. Intelligent Octopus Go, Cosy (if you have a heat pump) and other time-of-use products are covered in the tariff comparison. A dumb or failed smart meter will knock you off these tariffs. That is a bigger annual loss than the battery maths. See our note on smart meter compensation if yours is stuck in dumb mode.
You can install the battery first and switch tariff later. The wiring does not care. What you should not do is delay a wired install because you are still on Economy 7. The pack will earn on E7, and it will earn more if you later land on Go. 0% VAT on installed home batteries still applies in England, Scotland and Wales until 31 March 2027. After that the rate is expected to rise. Details sit on the VAT on home batteries page.
The plug-in battery adverts are not a legal whole-home solution
Search "Economy 7 battery storage" and you will find pages selling a pack you plug into a wall socket, sometimes with a CT clamp, sometimes with a claim that no electrician is needed. That is a different product from a whole-home battery.
A battery that feeds the house has to be connected on the consumer-unit side of the installation, with the right isolation, earthing and grid protection. In the UK that means an electrician, G98 or G99 with your Distribution Network Operator, and a BS 7671 / PAS 63100 location (garage, outbuilding, suitable outdoor wall. Not a loft, bedroom or escape route). Habo's 5 kWh STREAM / Solarbank is that kind of system: inverter in the box, hardwired, G98 class.
Plugging a battery into a 13A socket and pushing power back into the ring is not a legal way to run the house. We will not sell it, and we will not pretend the saving figures on those adverts apply to a compliant install. If a page says "no electrician required" for a whole-home Economy 7 battery, treat the rest of the claims with the same caution.
What size battery on Economy 7?
For Habo the answer is the 5 kWh all-in-one. That is the product. It is not a 10 kWh or 15 kWh wall kit, and it is not priced like one. From £2,499 fully installed, 0% VAT where that still applies.
On Economy 7, 5 kWh is usually the right first step rather than a compromise:
- It fills in a small slice of the seven-hour cheap window, so it does not fight storage heaters or an immersion for off-peak kilowatt-hours.
- It covers a typical evening of lights, fridge, TV, broadband and cooking on the hob, which is the expensive slice for many dual-rate homes.
- G98 keeps the DNO process as a notification, not a long G99 application, for a sub-3.68 kW inverter.
If your daytime use is consistently well above 5 kWh and you are set on shifting all of it, a larger system from another installer is a different job. Our what size battery guide walks through that. Do not buy a bigger pack just because Economy 7 lasts seven hours. Unused capacity does not earn.
Installation, not a DIY weekend
A compliant Economy 7 battery install is the same job as any other UK home battery install:
- Survey: consumer unit space, meter type, a legal location under the 2026 wiring and fire rules, and a sense-check of your off-peak times.
- DNO: G98 notification for a small all-in-one, G99 if the inverter is over the 16A / 3.68 kW line.
- Fit: electrician hardwires the unit to the consumer unit, not to a socket.
- Setup: charge window set to your Economy 7 (or later, Go) hours. One cycle a day is the simple, warranty-friendly pattern.
Habo is not taking deposits at the moment. Join the waitlist with an email. Nothing to pay today, no commitment, and we get in touch when we can book the installation. Pricing is on the pricing page. Finance options, if you need them, are on the home battery finance guide.
Frequently asked questions
Yes. Economy 7 gives you about seven cheap overnight hours. A 5 kWh home battery can charge in that window and then run daytime household load at the cheap rate instead of the expensive peak rate. You do not need solar. You do need the battery electrician-wired to the consumer unit. Plugging a battery into a UK socket to feed the house is not legal.
Usually no. Economy 7 has a longer cheap window (about seven hours versus five on typical Octopus Go) but a smaller price spread. On Habo's published figures a 5 kWh battery on a cheap overnight tariff such as Octopus Go saves about £300 to £360 a year, one cycle a day. On typical Economy 7 rates the same pack saves less, roughly £200 to £260 a year as an estimate, because the off-peak rate is higher and the peak-to-off-peak gap is narrower. If you can get a working smart meter and a Go-style tariff, that is usually the better battery tariff.
Not for Economy 7 itself. Economy 7 can run on a traditional dual-rate (multi-register) meter. The battery does not care which meter you have. It charges when you tell it to. A smart meter does matter if you want to switch to Octopus Go, Intelligent Octopus Go, Agile or most other modern time-of-use tariffs. Those need half-hourly readings.
No. A whole-home battery has to be hardwired to the consumer unit by an electrician, under G98 or G99 and BS 7671. Plugging a battery into a UK 13A socket and feeding the house from it is not a legal install. Some adverts sell that idea for Economy 7 households. It is not the route Habo uses, and it is not a route we would recommend.
For a typical small or medium household that wants to shift evening and daytime base load, yes. A 5 kWh all-in-one on G98 (inverter in the box, usually under the 3.68 kW notification limit) fills in well under two hours of the seven-hour Economy 7 window. That leaves the rest of the cheap period for immersion heaters, storage heaters or an EV if you have them. Larger 10 to 15 kWh wall kits shift more kilowatt-hours, at a different price. Habo's offer is the 5 kWh STREAM / Solarbank class, from £2,499 fully installed.
Bottom line
Economy 7 and a home battery are compatible. The seven-hour cheap window is generous for a 5 kWh pack, you do not need solar, and you do not need a smart meter to start. The honest limit is the spread: typical Economy 7 rates leave less money on the table per cycle than Octopus Go, so payback on a £2,499 install stretches unless you later switch. If storage heaters already justify Economy 7, keep it and add the battery. If they do not, get the smart meter working and move to a cheap overnight tariff. Either way, have an electrician wire it. Do not buy a socket battery and call it a house battery.
Stay on Economy 7, or switch later. The battery is the same.
Join the waitlist for a Habo Energy 5 kWh STREAM / Solarbank, from £2,499 fully installed, electrician-wired to G98 / BS 7671. Nothing to pay today. About £300 to £360 a year on a cheap overnight tariff such as Octopus Go, one cycle a day. Less on typical Economy 7, still a real saving. 0% VAT where that still applies.
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