Are you energy literate? Here’s how to tell – and it could make a massive difference to your bills

Knowing how much electricity a product consumes is not enough. You also need to understand how often – and for how long – you normally use an electrical gadget over a year

The blank refusal of the Tory government for over a decade to run any mass energy-efficiency information campaigns means that in the current fossil-fuelled inflation crisis, many people have been left energy illiterate.

Many people literally do not know how much more energy one plugged-in electrical product uses than another – and how lack of this knowledge can have a serious impact on their energy bills.

As a result, some families will be putting in loads of effort to reduce gadget usage that will save them buttons, while failing to reduce the consumption that may reduce their ability to put food on the table.

What I’ve written here is an attempt to start rectifying this. The crucial starting point is to understand that electrical products in the home are rated by how many kilowatts (kW) of electricity they consume in an hour. The higher the kilowatt rating, the more expensive the product is to run.

A kilowatt is a 1,000 watts. The amount of electricity a product consumes is measured in kilowatt hours (kWh), ie the rating of the product measured in kilowatts is multiplied by the time used in hours.

Thus, a 4kW-rated tumble drier, used for two hours, would consume 8kWh of electricity (4kW x two hours = 8kWh).

Electricity companies charge for electricity by the kilowatt hour. Under the Truss Tory government’s latest energy price cap, announced on 9 September, the price per kWh of electricity will rise 20 per cent to 34p and the price of gas per kWh will rise 40 per cent to 10.3p from 1 October.

To give readers a feel of the range in costs for operating various electrical or gas-powered products, I have produced the following list.

The first number in each line is how much energy the products use in an hour and the second is how much they would cost to run per hour at full output in pence. This will vary from brand to brand:

• 33kW: 353p Gas central heating boiler (semi-detached house)
• 24kW: 257p Gas central heating boiler (a flat)
• 3kW-16kW: 102-544p Air-source heat pump (depends on size installed)
• 9kW: 306p Electric shower
• 6kW: 204p Dual electric immersion heater
• 4kW: 136p Tumble drier
• 3.5kW: 37p Gas oven
• 3kW: 102p Electric oven
• 3kW: 102p Electric kettle
• 2kW: 21p Single gas burner on stove
• 2kW: 68p Single ring on electric stove
• 2kW: 68p Oil electric radiator
• 1.5kW: 51p 1 ring on electric cooker
• 0.9kW: 31p Microwave oven
• 0.56kW: 19p Infrared heating panel
• 0.320kW: 11p 42” plasma TV
• 0.2kW: 7p Slow cooker
• 0.1kW: 4p Electric blanket
• 0.06kW: 2p Laptop
• 0.05kW: 2p Halogen spot lamp
• 0.005kW: 0.2p LED light bulb
• 0.002kW: 0.1p Electric toothbrush

If an item that you use is not included in the list above, just google “how many kW does item x use?” and multiply the result by 34p to find out how much it costs per hour to run.

But knowing how much electricity a product consumes is not enough. You also need to understand how often and for long you normally use such an electrical gadget over a year.

Energy products in our homes vary from high-energy products we use a lot– to high-energy products we use rarely; down to low-energy products we use a lot and low-energy products we use rarely.

Knowing which is which is crucial if you are to cut down on your energy bills effectively. For example, cutting a family’s daily tumble-dryer usage down to once a week would save a staggering £424 over a year; while doing the same for an electric toothbrush would save a minute £0.31.

As another example, I picked another lower-energy item: halogen spot lamps. If you have 10 of them, running for four hours a day, that costs £291 per year. Whereas if you replaced them with 10 LED lamps, it would cost only £29!

Those who are already energy-savvy will have noticed from the list that by far the most expensive items to run in a home are space- and water-heating items.

But cooking and boiling the kettle – despite being highly rated – cost significantly less over the year than hot water and space heating systems, due to the length of time they are operating.

To keep up to speed with all the latest opinions and comment sign up to our free weekly Voices Dispatches newsletter by clicking here

These, therefore, deserve the most attention if facing difficulties in paying bills as costs rise sharply.

Heating only the room you are in – and only to the recommended 18C temperature (21C for non-ambulant elderly) – will save you the most in heating bills. Switching to a daily sink wash and using a small amount of water heated to just 40C in a kettle (to replace a shower or bath), combined with using the cold wash setting for your washing machine (for unsoiled clothing) will radically reduce your hot water costs.

Whether or not you need to cut energy consumption for cost pressures, all of us need to urgently slash our energy usage because of the climate crisis.

Until such time as we have a government with the courage to run a decent energy efficiency public education programme, the above explanations about where energy is mostly used in the home will hopefully help you to start saving more today.