How do energy tariffs work with home batteries?
A home battery saves money by exploiting the price difference between cheap and expensive electricity. You charge the battery during off-peak hours when electricity costs less, then discharge it during peak hours when you would otherwise pay full price. This is called load shifting. The bigger the gap between off-peak and peak rates, the more you save. Without a time-of-use tariff, a standalone battery does not save money.
The critical metric is the tariff spread – the difference in pence per kWh between your off-peak and peak rate. A spread of 15p/kWh or more makes battery storage financially compelling. Below 10p/kWh, the savings may not justify the investment. If you are new to home batteries, our guide to home battery storage systems covers the basics.
UK tariffs compared for battery storage
Octopus Go
Octopus Energy
Off-peak window: 00:30–05:30 (5 hours). Fixed, predictable pricing. Requires an EV to sign up but not enforced at hardware level. Requires a smart meter.
Intelligent Octopus Go
Octopus Energy
Off-peak window: 23:30 to 05:30 (6 hours). Requires a compatible EV and smart charger. The longer window gives more flexibility for larger batteries. Off-peak rate: 7.6p/kWh for six hours from 23:30 to 05:30 (Octopus, checked 10 October 2026).
Octopus Agile
Octopus Energy
Rates change every 30 minutes based on wholesale prices. Can occasionally go negative (you are paid to use electricity). Highest potential savings but least predictable. Requires cloud-based optimisation or active monitoring to maximise.
Economy 7
Multiple suppliers
Off-peak window: 7 hours overnight (times vary by region). Available from most UK suppliers. Higher off-peak rate than Octopus Go reduces total savings. No smart meter required (uses multi-register meter).
Which tariff saves the most money?
| Tariff | Typical annual saving | Predictability | Complexity |
|---|---|---|---|
| Octopus Go | Up to about £420 to £490 (5 kWh, best case) | High | Low – set a timer |
| Intelligent Go (requires EV) | Depends on your rates: use the calculator | High | Low – set a timer |
| Octopus Agile | Depends on your rates: use the calculator | Low | High – needs optimisation |
| Economy 7 | Depends on your rates: use the calculator | High | Low – set a timer |
The Octopus Go figure is Habo's best case for a 5 kWh battery: one full cycle a day, all used at the day rate, with an assumed 90% round-trip efficiency, so real savings will be lower (see how we worked it out). For other tariffs, put your own rates into the savings calculator. For a detailed breakdown of system pricing, see our home battery storage cost guide.
Our recommendation
For most households, Octopus Go or Intelligent Go delivers the best combination of savings and simplicity. The fixed off-peak rate makes your returns predictable, and the five-to-six-hour charging window is long enough to fully charge a 10kWh battery on a sub-3.6kW inverter. You set the charging timer once, and it works every night without intervention.
What is the tariff spread and why does it matter?
The tariff spread is the difference between your off-peak and peak electricity rate, measured in pence per kWh. It is the single most important number for battery economics. On Octopus Go the spread is 24p to 28p/kWh depending on region (checked 10 October 2026), or about 23p to 27p saved per kWh after an assumed 90% round-trip efficiency. Over a year, a 5 kWh battery on Octopus Go saves up to about £420 to £490 in the best case.
If your tariff spread is less than 10p/kWh, a battery will take significantly longer to pay for itself. Below 5p/kWh, the economics are difficult to justify unless you have solar panels generating free daytime electricity.
Do you need a smart meter?
Yes, for most time-of-use tariffs. Octopus Go, Intelligent Go, and Agile all require a SMETS2 smart meter. Economy 7 can work with a traditional two-register meter, but switching to a smart meter gives you access to better tariffs and more detailed usage data. Smart meter installation is free in the UK – contact your energy supplier to book one.
Timer-based vs cloud-optimised charging
There are two main approaches to scheduling when your battery charges and discharges.
Timer-based (set and forget): You configure a fixed charging window – for example, 00:30 to 05:30 to match Octopus Go's off-peak period. The battery charges during that window every night and discharges during the rest of the day. This approach is simple, reliable, and works without an internet connection. It is the approach Habo uses.
Cloud-optimised: The battery connects to the internet and receives dynamic pricing signals from a cloud platform. It adjusts its charging schedule based on real-time or forecast energy prices. This approach can extract more value from tariffs like Octopus Agile, but it adds complexity and creates a dependency on the cloud service being available.
Can you export stored electricity for profit?
In principle, yes – the Smart Export Guarantee (SEG) requires energy suppliers to pay for electricity exported to the grid. However, SEG export rates are typically low (3-15p/kWh), and buying grid electricity at 9.5p/kWh to export at 5p/kWh would lose money. Grid export is mainly valuable for solar homes with battery storage. For battery-only homes, the primary value is in self-consumption, not export.
What about future tariff changes?
The UK energy market is moving steadily toward more granular, time-variable pricing. Ofgem's Market-Wide Half-Hourly Settlement (MHHS) programme is transitioning all GB electricity meters to half-hourly settlement, meaning your supplier will eventually bill you based on exactly when you use electricity, not just how much. This makes time-of-use tariffs more accessible and more valuable.
For battery owners, this trend is strongly positive. As more tariffs differentiate between peak and off-peak pricing, the value of load shifting increases. A battery purchased today will likely become more valuable over time, not less.
Start saving on the right tariff
See how much you could save or read our detailed guide to Octopus Energy battery storage. Habo Energy batteries are designed for simple timer-based charging. Set your off-peak window once and save every day. Nothing to pay today.
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