Check if your home qualifies for a free battery
Homeowners and private tenants can apply. It only takes a few minutes.
How your electricity bill is made up
Most household electricity bills have two parts:
- A unit rate — what you pay for each kilowatt hour (kWh) you use.
- A standing charge — a fixed daily amount, whatever you use.
A battery can only affect the first part — the cost of the units you use. It doesn’t change your standing charge. If you’re on a standard variable tariff, Ofgem’s energy price cap limits the unit rate and standing charge you can be charged.
Tariffs with cheap and expensive periods
On a single-rate tariff, every unit costs the same whenever you use it, so there is little to gain from shifting when you use electricity. Other tariffs charge different prices at different times:
Two-rate tariffs
Tariffs such as Economy 7 offer a cheaper rate for a set block of hours overnight and a higher rate for the rest of the day. Read more about Economy 7 tariffs.
Smart (time-of-use) tariffs
Smart meters can record half-hourly consumption, so suppliers can offer tariffs whose price changes through the day. GOV.UK says these let consumers save money by using energy away from peak times or when there is excess clean electricity.
Charging and discharging to save money
On a tariff with cheaper and more expensive periods, a battery can charge when electricity is cheaper and discharge to power your home when it is more expensive — so fewer of the units you use are bought at peak prices.
How a smart home battery might run over a day. The battery charges overnight when demand is typically lower, holds its charge through the day, and discharges during the early-evening peak when demand is typically highest.
For the mechanics behind this, see how a home battery works.
Grid services
The electricity system has to balance supply and demand every second. Batteries can help by charging or discharging when the system needs it, and there are arrangements in the energy market that reward this kind of flexibility. For households, the value of this usually comes through a supplier, aggregator or programme rather than directly.
Why savings vary between households
- Your tariff — the bigger the gap between cheap and expensive rates, the more a battery can shift.
- How much and when you use electricity — a home that uses most of its power in the evening has more to shift.
- The battery’s size and power — how much it can store and how fast.
- Solar panels — if you have them, a battery can store surplus daytime generation.
- Efficiency losses — a little energy is lost each time a battery charges and discharges.
- Standing charges — these stay the same, whatever the battery does.
Be wary of fixed saving claims
Installing a battery does not automatically save a fixed amount. Anyone quoting a set saving for every home is oversimplifying.
The Free Home Battery Scheme: up to £500 a year towards bills
Separately from general battery savings, the Free Home Battery Scheme is looking to provide eligible households with up to £500 per year towards their electricity bills, subject to eligibility and programme terms. This is a benefit of taking part in the programme — not a saving that comes from installing any battery — and it isn’t guaranteed: some households may receive less.
The battery itself is supplied and installed at no cost to eligible households, and owned and looked after by the scheme owner. See the wider benefits of home battery storage.
Could your household receive up to £500 a year?
Start your application — it only takes a few minutes.
Other ways to cut your bills: see how smart meters can save you money and switching energy supplier.