Storage Heater Running Costs

Storage Heaters are designed to be used using cheap overnight electricity often called Economy 7 or Economy 10, these are Tariff’s which offer 7 hours (or 10 hours on Economy 10) of cheap rate Electricity, which allows the storage heater to ‘charge’ with heat, which is then convected to warm the room outside of the cheap rate period.

For this reason, Storage Heaters are not suitable for use on a standard, single rate Electricity Tariffs as doing so will work out extremely expensive, and very ineffective.

So lets work out how much Storage Heaters cost to run.

First of all, find out just how much Electricity each storage heater actually consumes. This will be stamped on a metal panel or label on the side or bottom of the heater.

If you cannot find the label with the electricity rating on your Storage Heater, then you can often find out how much Electricity your storage heater uses by putting the manufacturers name and the storage heater model into Google. For example ‘Dimplex XL24N’ into Google will bring up a website which tells you that the XL24N Storage Heater consumes 2.55KW of Electricity.

In fact there are 4 popular sizes of storage heater. Starting off with the smaller models of 850W and 1750W which are suitable for Bathrooms, Porches, and background heating of hallways and small bedrooms. Then there is a 2.55KW model, which is suited for medium sized areas such as standard bedrooms, and finally a 3.4KW model, which is recommended for Lounges and Living areas.

When working out the electricity consumption of an Electrical Appliance, it is easier to the rating of the appliance in ‘Kilowatts’ often expressed as ‘KW’

1000 watts = 1kw, 2000 watts = 2kw, 3000 watts = 3kw – fractions of each kw are expressed in decimals, for example 3400 watts = 3.4kw, 2550 watts would be 2.55kw

To work out how much storage heaters will cost to run, you need to use a simple maths formula, as shown below

Storage Heater consumption in kw x number of hours run x electricity cost in pence

You can find out how much your Electricity costs, by looking at a recent electricity bill. On an Economy 7 tariff, there will be two electricity rates given, one will be a daytime (peak) rate, the other will be a night time (off peak) rate, the cheaper off-peak tariff is the one that your storage heaters will be using overnight. So we will use this in our maths example, in order to work out the cost of running each storage heater.

So, we know that Economy 7 runs the Storage Heaters for a total of 7 hours, every night, so we now have the number of hours to put into the equation.

So lets work out how much it would cost for a 3.4kw storage heater to charge with heat, during a typical 7 hour economy 7 period.

At the time of writing this blog, Off peak economy 7 electricity cost between 5p and 6p per unit (kwh) of electricity, so we will use 5.5p as our working example.

So using the simple formula:- running cost = kw X hours run X cost

3.4 (kw) x 7 (hours) x 5.5 (p) electricity cost = £130.9p

So to charge a 3.4kw storage heater with heat for the 7 hour economy 7 period at an electricity cost of 5.5 pence per unit would cost £130.9 per night to run that storage heater.

Using the same 5.5 pence economy 7 off peak rate, I have also given the example below for the running costs of the popular sizes of storage heaters.

Running costs of Popular Storage Heaters, based on an example off peak Electricity cost of 5.5 pence per unit (kw/h)

850w (0.85kw) Storage Heater = £0.327p per 7 hour period
1700w (1.7kw) Storage Heater = £0.654p per 7 hour period
2550w (2.55kw) Storage Heater = £1.249 per 7 hour period
3400w (3.4kw) Storage Heater = £1.309 per 7 hour period

Electricity costs can vary, so to work out an accurate figure for your own Storage Heater running costs, simply enter your own figures into the calculator below. Remember to use your ‘off peak’ electricity kw/h unit cost in the ‘cost per kw/h field’

Online Calculator

(The calculator displays the cost figure in ‘$’ but the actual result will be the same in any currency, simply substitute the ‘$’ with your own local currency symbol)

Of course these are worst case figures, based on the storage heater warming from cold, and with any ‘input’ control set to its maximum setting. If you tend to use the input setting if your storage heaters on a lower number, then the storage heater will use less electricity than in our example above and cost slightly less to run, however this will mean that less heat is stored, and the room will cold cold earlier than if a higher input setting was selected.