Hendy Group Logo - Established in 1859
Waves background
Appears in 4 categories

kW and kWh explained: making sense of electric car energy

kW and kWh explained: making sense of electric car energy
4 min read Published 4 Nov 25

Explore new Ford vehicles

Electric driving comes with its own vocabulary. Acronyms like BEV (battery electric vehicle) and PHEV (plug-in hybrid) are becoming better known, but other terms can still be confusing. You’ll often see kW (kilowatt) and kWh (kilowatt-hour) pop up on car spec sheets – and they’re important if you’re comparing models and thinking about EV running costs.

At Hendy Ford, many of our loyal customers are exploring Ford’s electric and hybrid range for the first time. They often ask: what does kWh mean? And what’s the difference between kW and kWh? Let’s break it down!

The basics:
kW (kilowatt) is a measure of power. In the context of EVs, it typically means the power of the car’s motor and can also refer to the output speed of chargers.

  • kWh (kilowatt-hour) is a unit of energy and tells you how much energy you have stored – and the ‘amount’ of energy transferred to the battery from the charger.

  • The two work together to shape how your EV drives and how far it goes between charges.

In depth:

What is a kilowatt (kW)?

A kilowatt shows how much energy something can use or deliver at a single moment. For example, your kettle might use 2kW, while your oven could use around 3kW. For EVs, think of it like the strength of a car’s engine, only measured in electrical terms.

For example, if we take the Ford Mustang Mach-E. The Select trim has a 197kW motor, which produces roughly the same performance as a petrol car with around 268 horsepower. The bigger the kW figure, the more power the motor can produce and the faster it can accelerate. If we take the sporty GT trim, the 358kW motor is comparable to 487PS.

What is a kilowatt-hour (kWh)?

A kilowatt-hour measures energy over time, not power in the moment. If you run a 1kW heater for one hour, you’ve used 1kWh of electricity.

When you read about electric cars, you’ll see their battery capacity is also listed in kWh. A vehicle with a higher kWh rating can store more energy, so it can travel further on a single charge.

Let’s take the Ford Puma Gen-E as our next example. It has a 43kWh battery. That means it can store enough energy to deliver 43 kilowatts of power for one hour. In driving terms, if you’re driving in the city, Ford states the Puma Gen-E has an energy consumption of 9.8kWh/100km, giving it an electric range of 314.4 miles. Not bad, right?

Top tip: While the battery kWh gives you a steer on range, it’s a bit like the fuel tank in a petrol car – the mileage/range ultimately depends on other factors too, like your driving style.

So when people ask us “kW vs kWh, what’s the difference?” or “what does kWh mean for electric cars?”, the answer is: it’s a way of expressing how much energy the car can carry, just like petrol cars use litres of fuel.

And if you’re wondering about hybrids, the same applies – the kW and kWh figures tell you how much the battery and motor can support the petrol engine and power the car in EV-only mode.

How many kWh does it take to charge a car?

You’ll often look at kWh in the context of the cost of running an electric car as well as how fast you expect your EV to charge – particularly important for those who find themselves on the road often during the working day.

Here’s how your car’s kWh figure could work in the real world. If the battery is 60kWh, for example, and you plug it in from nearly empty, it will take about 60kWh of electricity to reach a full charge (a little more due to energy losses). Let’s say your home energy tariff is 24.5p per kWh, it would make a full charge cost around £13.*

Top tip: For public chargers, you can find up-to-date charging prices in the FordPass app, where you can also see stations that are part of the BlueOval Charge Network on a map.

Jargon buster:

 Credit tariff per kWh – the unit rate you pay for each kilowatt-hour of electricity.

  • Price cap per kWh – refers to the maximum unit rate energy suppliers can charge domestic customers under UK regulations.

  • IMP kWh – if you see this on your smart meter, it means imported kilowatt-hours – the amount of electricity you’ve drawn from the grid.

    Making the switch with confidence

    Understanding these terms helps you see how electric vehicles fit into everyday life. You’ll be able to compare battery sizes, charging times and running costs with confidence.

    At Hendy Ford, we’re always happy to walk through what these numbers mean in real-world terms, and help you compare the latest Ford electric models. Contact our friendly team today to find out more.

    So, the next time you see kW and kWh in EV specifications, you’ll know exactly what those numbers are telling you – and why they matter for your next drive!

    *Costs calculated at 24.5p/kWh based on usable battery of ~54kWh (90%). Source: Pod Point, accessed 23 October 2025.