Standing Charges and Unit Rates: Which Half of Your Bill a Battery Can Change
- The standing charge is a fixed daily amount and does not depend on how much electricity you use.
- The unit rate is the price per kWh and is the only part a battery can reduce.
- Ofgem's price cap limits both the unit rate and the standing charge, not your total bill.
- Standing charges differ by region, so two households can see different splits.
- A battery saving is built from the unit rate, so use your own bill when you test an estimate.
An electricity bill has two parts: a daily standing charge and a price for each kWh. A home battery can only affect the second one, so it pays to know the split before you estimate any saving.
The two parts of the bill
Every household electricity bill is built from two numbers. The standing charge is a fixed daily amount you pay for being connected, whether you use a lot of electricity or none. The unit rate is the price for each kWh you use. Ofgem describes the price cap as limiting the unit rate and the standing charge, and says it does not limit your total bill, which rises with how much you use.
Your supplier shows both on your bill and in any tariff comparison. If you are testing a battery idea, start by finding both numbers.
What sets the standing charge
Ofgem's own page on standing charges says the charge differs depending on where you live. It lists four influences: the number of people in your region, average energy use in the region, how much energy the supplier has to buy, and the cost of building and improving the energy network.
The page does not give a detailed breakdown of what each daily pence pays for, and we could not confirm a split. What matters for a battery owner is the simpler fact: the standing charge is fixed per day. It is paid in full even if your battery covers nearly all of your evening use.
Check your own bill
Find the standing charge in pence per day and the unit rate in pence per kWh on your latest bill or in your supplier app. Use those two numbers, not an average.
Why a battery works on the unit rate only
A home battery stores electricity bought at a lower price, or generated by your own panels, and lets you use it when the grid price is higher. That changes how many kWh you buy and when you buy them. It does not change the daily charge for being connected.
This has a practical result. On a tariff with a high standing charge and a low unit rate, the unit rate gives a battery less to work with, so there is less for it to save. On a tariff with a lower standing charge and a higher unit rate, the same battery has more room to save. For an overview of how a battery saves anything at all, see how a home battery saves money.
How to use this when you estimate savings
When you read a saving estimate, ask which price it uses. A sensible estimate multiplies the kWh the battery actually shifts by the gap between the price you would have paid and the price you pay instead. It should not include the standing charge in the saving.
If a quote or website talks about cutting your bill by a percentage, check whether it counts the standing charge as part of the bill it expects to reduce. Our UK savings guide walks through the arithmetic, and the calculator lets you enter your own rates.
Common questions
Can a home battery reduce my standing charge?
No. The standing charge is a fixed daily amount for being connected. A battery changes when and how much electricity you buy, not the daily charge.
Does the price cap limit my total bill?
No. Ofgem says the cap limits the unit rate and the standing charge, so your total bill still rises with how much you use.
Is the standing charge the same everywhere in Britain?
No. Ofgem says it differs depending on where you live.
Should I pick a tariff with a low standing charge if I have a battery?
It can help the unit rate matter more, but compare the whole cost at your own usage before you decide. A lower standing charge often comes with a higher unit rate.
Related guides
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