What does kWh mean?

What is the difference between a kW and kWh?

*deep breath*

Ok, so this is sort of obvious but also sort of confusing.

A kW, kilowatt, is the amount of power an appliance needs to work.

For instance, normal electric clothes dryers need between 1800 to 5000 watts to work – and will be labelled as such. This means they pull that power out of the grid or your energy system.

A kWh, kilowatt per hour, is how much energy that appliance will use in any period of time.

So, how many kWh do most appliances use?

Again, no simple answer to this but all new appliances will carry their rating somewhere on the casing or in the user manual.

Let’s take a closer look at some popular home appliances to give you an idea though:

100-Watt Bulb (Incandescent) – 100Watts
49 Inch LED TV – 85 Watts
Coffee Machine – 800 Watts
Dishwasher – 1200 Watts
Cooker Hood – 20 Watts 
Electric Blanket – 200 Watt
Induction Hob – 1400 Watts
PlayStation 5 – 200 Watts

No surprises on that list as we would expect anything with a heating element to be power heavy in comparison to a games console or TV.

Though, saying that, we think most of us are oblivious to the amount of electricity each item in our homes uses and how much they cost to run.

Learn more about how much energy your appliances use.

How much does 1 kWh of electricity cost?

Historically, this has changed from year to year and from supplier to supplier.

However, with the cost-of-living crisis in full effect and the energy companies still raising their prices, Ofgem has capped a unit, or kWh, at around 24.50p.

When you see news about the energy cap being £2500 or £3000 per household, this is not strictly true, as it’s only the unit price that is capped, not the cost of your bill.

So, now is a good time to start familiarising ourselves with how much electric we use and how much each appliance costs us.

How much am I spending on power for my appliances?

We can only work on averages in this section as the more expensive the item the more efficient it usually is.

So, looking at a few key household items, plus the average time they would be in use, and the current price of electricity (0.245p):

• • iMac: 240 watts x 8 hours a day. 0.24 x £0.245 x 8 = £0.47 a day. That’s £171.70 a year.

• • Tumble dryer: 750 watts x 2 hours a day. 0.75 x £0.245 x 2 = £0.37 a day. Comes in at £134.14 a year if used twice a week.

• • Air Fryer: 1,500 watts x 30 mins a day hour a day. 1.5 x £0.245 x 0.5 = £0.0.18 a day. So, £67.06 a year.

• • Fridge: 200 watts x 8 hours a day. 0.2 x 8 x £0.245. That’s £0.39 a day. A cool £143.08 a year.

• • Kids’ nightlight: 400W x 14 hours a day. 0.40 x £0.245 x 14 = £1.37 a day. £500.78 a year.

What determines my electricity cost per kWh on my energy bill?

This would normally be set by your energy provider based on how much they pay for their electricity at wholesale prices.

However, as fuel prices have been increasing so much lately due to various external reasons such as conflict, transportation and fuel scarcity, the price of a kilowatt per hour has been capped at around 24.50p.

Ofgem are the body that set the price cap and they monitor suppliers to ensure they are complying to the correct rates.

To set the cap Ofcom look at:

Wholesale Energy Costs – price suppliers pay for their energy

Network costs- this is the price to maintaining and investing in the networks needed to supply energy to your home.

Supplier operating costs – how much it costs to run an energy company from wages and training to vehicles and customer service.

VAT: – 5% tax is added to the level of the tariff.

Ofgem will look at an average domestic user on using an average amount of energy.

It is worth remembering that the price cap isn’t on your whole bill, it’s just on the amount each kWh is. The more you use the more you will pay.

How many kilowatt hours should I be using each year?

This is not an easy question to answer accurately, but we’ll have a go using averages.

Ofgem state that the average home uses 2,900 kWh of electricity and 12,000 kWh of gas in a single year.

You will use more than this if you work or run a business from home, have medical equipment or have hobbies that require heaters or fridges.

If you have a smart meter, you should be able to get a pretty accurate measure of your usage but, if you don’t you can always keep an eye on your normal electricity meter.

Can I use kWh to compare energy costs?

Yes and no.

Because of the energy crisis, conflict in Ukraine and leaving the single market, fuel prices have rocketed (like you didn’t already know that!) so they are currently being capped.

Most energy companies are now charging a flat 0.245p per kWh as they can’t charge anymore.

If the market returns to ‘normal’ and the suppliers start to act competitively again then you will see different rates for a kWh of electricity.

Can you become an energy-saving expert?

While we wouldn’t say that everyone can become an expert on energy unless they work in the industry, or take a special interest, you can certainly work out what you’re spending on energy and find ways to save.

This isn’t simply a case of shouting ‘Turn that light off!’ every time the kids leave the room, there are other less obvious ways to save energy.

‘Loading’ can be a big factor and this is down to how many items you have on at once in a home with a solar energy system.

If you use the cooker, the tumble dryer and an electric heater, all at the same time, the load will be huge, which will either drain the battery or overload the panels.

You won’t damage anything doing his, but you will run out of stored energy very quickly and you will not be able to power the appliances straight from the panels.

We would say that telling the kids to turn things off is still sound advice.