Cost to Charge an Electric Car?
The fundamental shift for new EV owners is altering how we think we about ‘filling up’ our cars, switching from a ‘pound per litre’ cost calculation to ‘pence per kilowatt-hour’. Once we have our heads wrapped around that, it’s time to consider the different elements that will impact your charging bills:
Your EV’s battery size
Your EV model
Your electricity tariffs
Your chosen EV charger (in terms of power output and functionalities)
Here’s a couple of ways to work out your charging costs in a nutshell:
Calculation Formula based on Load:
Battery Size/Availability x Rate = Cost
Calculation Formula based on Time:
Charger kWh x Hours x Rate = Cost
Charging at home from the grid
It seems only fitting to start where most of your charging will occur; at home, this is by far the easiest, most convenient and potentially, the cheapest long-term option for charging your EV. The cost to charge at home will vary on a couple of factors, including the time of day you choose to charge and what energy tariff you are on.
Let’s consider your current electricity tariff is a flat rate of 14p per kWh, you own a Nissan Leaf that has a battery size of 40 kWh, and you drive the national average of 7,000 miles a year. To fully charge the battery from 0% to 100% will cost you £5.60. The ‘real-world’ range on a Nissan Leaf is approximately 150 miles which provides you with a per-mile cost of just over £0.037 and an annual cost of £262.
Even on a flat rate energy tariff, you’re likely to be making some savings, but there’s more to be had if you consider switching to an Economy 7 tariff or one of the smart tariffs from EV friendly suppliers. For example, Octopus Energy offers 4 hours of super off-peak electricity, charging 5p/kWh between 12.30 and 4.30 am.
Taking advantage of overnight tariffs can result in significant savings; however, this is where you will need to consider timings and charger output. For example, we need to charge our 40kW battery from empty to full using a 7kW charging device; this will take roughly 5.7 hours. Four hours of charging at 5p/kWh will cost £1.40 with the remaining 1.7 hours at 14p/kWh costing £1.67, giving you a total charge cost of £3.07 and an annual cost of £143.27.
Ok, I know this is beginning to sound like a middle school maths test but bear with me.
If a smart tariff isn’t appropriate for your household, you could reap some additional benefits by switching to an Economy 7 tariff, whereby you get 7 hours overnight of cheaper energy with a higher rate during the day. In this scenario, you would be able to achieve a full charge using the lower price of around 8p/kWh with a total cost of £3.20 and an annual cost of £150. As a result, the Economy 7 option may prove more beneficial for those with a larger battery capacity or a slower charging device.
Of course, these are all estimates, calculated to provide you with an idea of cost. Ultimately it will come down to your chosen energy tariff, and that is a variable that will be different for everyone, depending on the demands of your household. If you work from home, use all of your appliances (such as dishwasher, washing machine and kettle) during peak hours, then Economy 7 or a smart tariff may not be an ideal solution. Nevertheless, there are deals to be had, and if you combine savvy energy switching with a smart charging device that enables greater control over each charging session, you’ll soon be recouping the initial outlay costs of purchasing an EV.
So Lets have a look at the cost to run a 2018 Nissan Leaf (40kW battery) for a whole year
|Miles/Year||5000 Miles||7,500 Miles||10,000 Miles||12,500 Miles||15,000 Miles|
|Charge at home|
7p (off peak)
|Charge at home|
7p (off peak)
|Charge in Public|
30p off peak
Charging at home using domestic generated energy
Using domestic generated energy is where the cost of EV charging gets exciting. If you have access to solar panels and/or wind turbines at home, then you can utilise these eco-power sources to charge your vehicle for free. Essentially driving on sunshine (or wind).
There are two ways that you can transfer this free electricity into your car, firstly by charging while you’re generating or using a battery to store energy. Let’s take a look at both options.
Let’s imagine, it’s a glorious Saturday afternoon in mid-June (it does happen), and your solar panels are generating 3kWh of energy. The household demands 1kWh, leaving a surplus of 2kWh that can be directly transferred to your EV if it’s plugged in and ready to charge.
Charging at home using domestic generated energy and battery storage
While the use of solar panels and wind turbines can significantly reduce the cost of charging your EV, installing a battery storage system has the potential to eliminate those costs entirely. With a renewable electricity generation system at home, you will inevitably generate more electricity than required at times of high supply and low demand (when everyone is at work and the sun is shining, for example). The installation of a battery storage systems means you can store that free generated energy for use at a later date, rather than directly exporting it to the grid.
Consider the solar example above but now we’ll incorporate the use of a storage system. Instead of pulling the additional 5kWh from the grid, the charger can use 2kWh being generated, plus 4kWh from stored energy and 1kWh from the network, providing you with a full 7kWh for 13p. Alternatively, if you have access to a higher capacity battery, you could pull the entire 5kWh from storage making your charge cost a delightful zero pence.
Additionally, many people are taking to storing up energy from the grid when it is at its lowest cost, taking advantage of night-time tariffs and unexpected price drops. Even without domestic generation, you could use a battery source to continually stock up on 5p/kWh and use that energy to charge your vehicle, regardless of the time of day. That would leave our Nissan Leaf user with an annual bill of £94 to travel 7,000 miles. Not bad.
It is worth noting here that installing batteries at home remains costly and is typically adopted by those with a home generation system. Given the infamous and unreliable nature of British weather, installing a battery provides you with access to free energy at times when your car is available to charge, and your system isn’t generating much energy; in the evening or on a dreary January weekend for example. Nevertheless, as these technologies develop further, prices will drop and the option to go off-grid becomes ever more achievable.
Charging at Work
Workplace EV schemes are quickly being adopted by large and small organisations. This is excellent news for all current and aspiring EV owners. The even better news is that charging at work is typically free, making it a desirable option. Aside from organising usage times with fellow colleagues, there are only benefits to making the commute in an EV.
If your company has yet to install charge points, round up fellow EV drivers (and those considering it) to pitch the scheme to HR. Typically companies need to be made aware of the demand before making the investment.
Charging on the Road
Even the savviest of EV drivers may find themselves on a long trip that requires charging on the road. There’s a couple of options outside the home, most of which will depend on the journey you are making and the time available.
Pit stops at service stations with rapid chargers along your route may be the most convenient option; however, it is also the most expensive. This is due to higher costs per kWh, which averages around 30p, depending on the supplier. Although regular use is likely to bump up your annual charging costs considerably, the convenience, speed and reliability are sometimes worth the price, with 80% battery charge by the time you’ve had a coffee.
You don’t always have to opt for rapid chargers. There are plenty of publicly available charge points for a more reasonable cost of 15-20p/kWh and many more that are entirely free to use. The free options are typically located in supermarkets, retail parks or shopping centres. Anywhere your time is valuable, companies are increasingly leveraging free charge points to entice consumers to visit.
EV v ICE (Internal Combustion Engine)
According to motoring research, the average monthly spending on fuel each month in the UK is £67.63, that’s an annual bill of £811.56. Regardless of energy tariffs and charging on the road, EV charging costs remain a fraction of what traditional vehicle costs. When considering maintenance and tax costs, the savings become even more apparent with minimal servicing required on the majority of EV’s.
Historically EV’s have been considerably more expensive than traditional motors, as that progressively shifts to more reasonable price comparisons, the savings to be had on running an EV will only become more pronounced with minimal servicing required on the majority of EV’s.