My Urban Car

Getting local EV Public Charging right. Part 1- Cost

Getting acceptable cost and utilisation rates

The conventional wisdom is that charging an electric car costs much less than running a car that burns petrol or diesel, but is that really the case? In this article we compare the cost of various charging options to uncover the real position and find the cost of charging varies to an insane degree compared to petrol, or diesel..or indeed compared to the price of electricity.

We believe that resolving the issues raised in parts 1, 2 and 3 of this series will increase not decrease the revenue for charging networks and help repay the capital costs of chargepoint installations more quickly, providing a better return for shareholders.

1.0 How did EV charging end up different?

According to Zapmap as at the 10th October 2020 there are 19,791 charging devices for Electric cars in the UK at 12,495 locations. So why is filling up with electricity a world away from filling up with petrol or diesel? After all it’s just buying energy.. in fact in many ways it should be simpler as electricity comes off the power grid at a pretty stable price of around 4p per kWh so it should just be a case of plugging in and paying a reasonable and clearly listed price that you know for the power you use? If only.

Many EV charging companies began as pioneers and needed subsidy from taxpayers or businesses like supermarkets. There were few EV owners and many of those charged at home very cheaply, only using public chargers when they had to. This probably led to the membership model, which enticed drivers with a reasonable sounding price per kWh compared to home charging, but made possible because the driver was paying a monthly fee. Move on to 2020 with more mainstream adopters switching to EVs and this is what they may find. To use where they are coming from as an analogy

  • Imagine a world where petrol was available 90p a litre in some filling stations but completely free or £2.50 a litre in others round the corner
  • Imagine many owners could avoid any high prices by filling up at home for around 60p a litre during the day(or 25p a litre at night)
  • Imagine some filling stations required you to give your name and address and type in your bank details when you fill up.. or even sign a direct debit or made you pay a joining or monthly membership fee before you can buy any fuel
  • Imagine you fill up with 10 Litres of fuel at 1.14 a litre but you are billed £20 because the station only bills in £10 increments
  • Imagine you had to download an app for every brand of filling station you visit or be surcharged by 30% or more to pay contactless with a debit card when it is available!
  • Imagine if many places you fill up arranged their pumps so their hoses can’t reach the nozzle of some of the best selling cars

In the strange world of UK EV charging the price of powering an electric car and even how you pay will vary wildly. For those in government providing public funds for public new chargers they probably can’t imagine how wildly different charging options vary

What are the key components of a successful local public charging strategy?

  1. Cost of charging
  2. local charging mix
  3. Ease of use and payment

1.1 Cost of charging

Slow Charging near home should be available a price not too far removed from the cost of charging on a driveway at home

EV’s have yet to reach cost parity with diesel and petrol vehicles (in fact some EV versions of the same car will cost over 50% more) so lower running costs are a key driver for EV purchases. This benefit is lost if “on street” providers charge far far more than someone who can charge at home. Yes, pricing has to reflect the cost of installing and maintaining infrastructure but pricing should also reflect public funding that has been contributed.

Essentially to succeed in making EVs work for all,  it is important people in flats and houses without driveways are not unreasonably discriminated against in the cost of running their electric car or van. Not only that with 4 lamp post chargers in my street about half the charging is by owners of plugin hybrids. If public charging costs more even than petrol then many owners will run on fossil fuel instead, producing CO2 and pollution just because the pricing is wrong.

Our research suggests that for each 1,000 miles travelled EV owners can expect to pay between £14 and £40 charging at home while those using public chargers without an additional monthly membership fee will pay between £68 and £196. For those whose cars charge slowly (including most plugin hybrids) one slow charging network in London will cost over £600 for electricity that costs £14 wholesale. If that’s not bad enough if you decide to do a complete charge on the same network and the charge finishes off at a rate of around 1kW the electricity could be costing you over £3,000 per 1,000 miles.

1.2 So how do EV charging costs compare with petrol or diesel

The website Fuel Economy UK has a handy calculator for fuel cost in a petrol or diesel car. A 1,000 miles for a car averaging 35mpg would be £148 at 114p per litre up to £169 if fuel is 130p per litre.

A car delivering 45mpg as a long term average on the road would cost between £115 to £131 per 1,000 miles at 114p-130p per litre.

Using the example of our own Tesla Model 3 Performance with aero wheels it used 285 Wh/ml over its first 5,000 miles which equals 285 kWh per 1,000 miles. So how does different charging cost compare per thousand miles based on the different costs per kWh.

Drag the table right if you can’t see the cost per thousand miles >>

Charging Tariff Speedpence per
Cost per
1,000 miles
Ionity contactless350kW69p£196.65
Source London Pay
as you go
Petrol or diesel
35 mpg average
at 130p
per Litre
Source London flexi7kW£10 joining
then 50p*
BP Polar contactless150kW42p£119.70
Instavolt Contactless50-125kW40p£114
Petrol or diesel
45mpg average
at 130p
per Litre
Shell Contactless50-150kW35-41p£99.75-116.85
Geniepoint Contactless50kW+39p£111.15
BP Polar contactless50kW35p£99.75
Tesla Supercharger*120kW-
Gridserve 120kW-
Gridserve Braintree22kW-
Ubitricity lamp post7kW24p£68.40
Home charger peak7kW14p£39.90
Home charger off peak7kW5p£14.25
*Tesla prices now vary by charger usually between 26p & 34p. Some London chargers vary between 20p & 40p for peak and off peak times

In summary then the most competitive 24p provider costs nearly double an average peak rate charge on a home charger & around 5x the off peak rate on an overnight tariff while a visit to a 350kW Ionity charger will cost 22x the cost of an off peak charge on a home charger.

If you compare diesel or petrol cost with an efficient 285Wh/ml EV charging cost parity compared to the current price of petrol (using 114p per L at October 2020) on a 45mpg car is about 41p a kWh. On a 35mpg car piston car EV parity is 51p per kWh.

Some EV’s will consume much more than that. For example an EV consuming 400Wh/mile would need 37p per kWh or less to be the same as a 35mpg petrol car or 29p per kWh to match a 45mpg vehicle on cost.

The take out here is that the average cost to public charge in the UK of 35p per kW will give a small 15% saving compared to an efficient 45mpg fossil burning car and 10% savings on a thirstier EV. Any Uk charging at over 41p a kWh is more expensive than a fossil car doing 45mpg while any charger costing over 51p is costing more than a 35mpg car. For example a trip using entirely contactless Ionity chargers will cost 71% more than in a 45mpg petrol car. This is actually flattering to the EV costing on motorway journeys as the EV will likely consume more than its average even at 70mph. Of course there is one network that charges most drivers much more than Ionity..

1.3 The most expensive electricity in the UK (that we know of)

Congratulations London, your biggest charging network with over 1,000 chargers across 23 London boroughs (and 2,000 set to be installed in 2020) is by far the most expensive major charging network we have found in the UK. Source London bills per minute so to work out the per kWh costs we have multiplied by 60 then divided by a charging speed or 7 or 22kW. It is a mystery what politicians & Source London believe there is benefit in having a charging network with dedicated parking bays that is so expensive (around 15x the wholesale cost of electricity) that they are virtually unused. Investing in expensive infrastrucure is not economic if your utilization rates are low ie no one uses them.

*Source London tariffs

1.4 The problems with billing by the minute for electricity- a pint of Guinness analogy

The billing method at Source London also causes further issues by being per min rather than per kWh you use. Imagine ordering a Guinness and being billed £2per minute it is poured than paying per pint. Essentially 80% that might take 2 mins to pour would cost you £4. Then the bar staff wander off while it settles and finish pouring that last 20% after 2mins.. so the last 20% costs you another £4. In fact in this example you pay £8 per pint, but the first part costs the equivalent of £5 a pint while the last part cost you the equivalent of £20 a pint!

Some older EVs & most “plugin hybrids” are “slow pourers” able to charge at a maximum of 3.7kW. For these users a 7kW Source London pay as you will cost £1.13 per kWh on their 7kWh chargers (£322 per thousand miles)

1.5 Billing per minute on 22kW AC chargers

Even EVs like a Tesla Model 3 that can charge at (in theory) 250kW on a DC charger can only charge at 11kW on the AC power that Source London provides. So why is Source London installing these chargers that cost much more to charge on when no cars can take advantage of it. . Many owners will not have appreciated that their car with super fast DC charging is much more limited on AC.

In fact we are only aware of one car sold in the UK that will charge at 22kW on AC – the new Renault Zoe. We have found 2 EV’s that will charge at 16kW (Tesla Model S&X). Some EV’s will charge at 11kW but the majority can only charge at 7kW. Most Plugin hybrids are 3.7kW although new models are getting faster. This pricing model is also punishing for owners of older EV’s that also charge more slowly.

The 22kW Flexi cost ( a little cheaper than pay as you go after a 1 off £10 registration payment) is 11.9p per minute (about double the cost of 7.4kW chargers on the same tarrif. This is how the cost works out on different charging speeds and the cost for £1,000 miles on an efficient EV that uses 285kWh per mile

1.6 Charging costs on a 22kW Source London charger

AC charging
Cost per

…and it gets worse- the UK’s most expensive electricity

EV’s will slow down charging speed towards the end of a charge. Many owners won’t realise what an impact this has on a Source London charger. A full charge to 100% or worse still topping up from 80-100% might end up on 1-2kW speeds.

Just to be clear on the Source London 22kW Pay as you go tarrif tariff of 14.3p per minute, this equates to a per kWh cost rising from 39p to £8.58 at 1kW speed, £4.29 at 2kW or £2.86 at 3kW. The wholesale price of electricity is around 4p per kW so the markup is between 107 times and 214 times the price of the power you receive! The result is 1,000 miles for an owner repeatedly topping up their battery to 100% would work at at £855 at 3kW, £1,222.65 at 2kW or £2,445.30 at 1kW!

It’s also worth noting that this Tesla is efficient at 285W/1000 miles. On a less efficient EV like an Audi e-tron 55 that is estimated to use 380Wh per mile would cost a third more to charge so at 1kW speed this last bit of your charge will cost you the equivalent of over £3,260.40 per 1,000 miles or £1,630.20 at 2kW. Thats equivalent to paying £25.07 or £12.53 a litre in a 35mpg petrol or diesel car.

The Source London business model appears to be fatally flawed both as a use of space and public funds and a very poor return on capital by Source London’s owners. Source London has just been sold to Total, the French oil company and we really hope they will introduce new pricing model, billed per per kWh that is affordable and justifiable. They will then get utilisation up to decent levels on chargers that are currently a waste of space.

In their defense their chargers do include parking but there is no discount for residents (certainly not in all boroughs) indeed the quoted rates are subject to an additional surcharge of 1.4p per minute or 84p an hour in the London Boroughs of Camden, Westminster and Kensington and Chelsea which we did not include in our review. We have not done a comparison of charging cost with local parking costs per minute for non residents but in many areas they are the only charging option.

Is Source London ever good value?

Well Source London do, at the moment, cap their overnight bills at 4 hours if you start your charge after 8pm. So, you find a 7.2kW charger (not a 22!) and you charge after 8pm AND you have a big empty battery then anything over 4 hours reduces the rate. For example if you charge at 7.2kW for 8 hours getting 57.6kWh of electricity then the rate per kWh would be half. Any longer and it would cost less then half. Here’s what that would do..

  • full tariff (requiring a £4 a month subscription) would cut from around 30p to 15p per kWh
  • a flexi ( one off £10 fee to join) would fall from around 50p per kWh to 25p
  • the pay as you go falls from around 60p to 30p

So yes.. if you have a big EV with a big and empty battery you could with an overnight charge of over 8 hrs, match or even beat the 24p per kWh cost that a ubitricity lamp post will cost you for every charge, big or small, day or night!

1.7 A London charging success

If Source London is London’s ugly sister (until it comes up with a new business model) then ubitricity’s lamp post chargers are Cinderella. After a rocky start (when all its chargers needed you to buy a £299 “smartcable” to connect up) most lamp posts will now let you plug in with your own cable for 24p per kWh. Yes that is still more than the 5p you might pay off peak or 14p peak at home but compared to other public charging its a good deal as it requires no sign up fee and no monthly membership fees. Also the price is the same whether you are charging a Zoe or first generation Nissan Leaf.

Paying only requires a QR code scan and entering name, card details and email. By UK public charging standards where you can be entering details for 20 mins sometimes ubitricity is a saviour.

Could be it better? Yes. the bays in front of the lamp posts are not dedicated for EVs and so often not accessible for days or weeks at a time.. probably why they install 3 or 4 per street. These chargers would be used much more if they got EV only bays rolled out in line with demand. Ubitricity could also let you use their app without having to spend £299 on their cable so users could save time inputting their payment details repeatedly.

1.8 A fair price for public charging?

Electricity is almost universally available in the UK. It is also broadly available at the same price across the UK. So while we get the concept of there being a cost surcharge for a privately funded very fast charging of over 125 kW speeds, and a smaller uplift for 50-100 kW speeds, network providers and those in government are failing if they are delivering a 4p commodity at the wildly different costs we have at the moment.

We believe a target price of 20-25p for under 50kW, 26p to 33p for 50 to 100kW and 35p to 45p for speeds of 125kW upwards should be achievable if the market was functioning properly. Indeed on a 4p per kWh commodity these prices seem generous.This is also a failure for shareholders because installing under-utilised or unused assets is a poor return on a largely fixed cost investment. This also matters to Government. Not only is there a question of whether public money should go to chargers that have extraordinary markups for EV owners, they also make the prospect of slapping a “fuel duty” on charging at some future date impossible.

Surcharge for contactless payment? Really?

We also think that Network providers are playing ducks and drakes with the Government when claiming competitive pricing per kWh via an app or monthly fee model.

Much of the industry has had to be dragged to provide payment on contactless debit cards but are levying enormous uplifts for these payments. If customers woke up one morning to find paying contactless pushed up the prices in shops or restaurants by 20% or because a retailer wanted you to pay via their app, most people would be pretty hacked off! In a market that functions properly normal payment via a bank card should not be treated differently to a shop. Some charging Network providers are claiming to have ticked the “contactless payment” box and then pricing it off the menu. That is not a tick and bank card customers should be treated fairly.


Despite the the need for change there is good news here. For consumers the Government has announced, since this article was first published, that they plan to mandate clear billing per kWh for all EV charging.. at a date to be decided.

The best news though is that problems with pricing models are the easiest to fix. You don’t have to replace all your chargers to adjust a pricing structure. Many chargepoint providers are delivering good value charging already and will be getting more customers to their chargepoints as a result. It is a little surprising that some others need the government to explain to them that reasonable pricing will bring more business and better returns but the signs are that is exactly what is in about to happen.

This brings a side benefit…if chargers are used more of the time some of the more outlandish predictions of how many chargers we will need by 2030 will be put to one side.

As an example BP Pulse has 7,000 UK charge points which it says delivered 16 million kWh of electricity in 1m charging sessions in 2020. Sounds impressive doesn’t it, but that equates to

  • 143 charges per year per chargepoint
  • This means, on average these chargers wait around for 2 and a half days between customers
  • The average power delivered per chargepoint is 2,285kWh per year and 16kWh per customer
  • If on average were charging at 50kW (many are slower but some are now 150kW) these chargers would only need 45.7 hours a year to complete their current sales! and yes thats hours not days!
  • If by comparison the same chargers were used for an average of 5 hours a day they would sell 91,250kWh of electricity which at 25p per kWh would gross £22,812
  • This certainly appears to demonstrate that existing charging infrastructure has a lot of spare capacity to service more EVs on our roads

Investing capital in underused assets is not good business. So as more EV’s come onto the road it will be in everyone’s interest to provide competitively prices charging in a functioning market that benefits consumers and providers alike.

Next : Part 2 Local Charging Mix

David Nicholson

David Nicholson Is the founder of Rivergecko Ltd & MyUrbanCar which provide consultancy and advice for drivers and fleets to speed the transition from dirty fossil fuel transport to clean vehicles powered by renewable energy on land water and air.

The @MyUrbanCar twitter feed is a source of news & reviews of electric & plugin cars and vans in the UK.
The @rivergecko twitter feed & websites bring news and opinion on cleantech transport including cars, vans, buses, trucks, shipping, rail & aviation as well as autonomous vehicles & renewable energy, air pollution & motor industry news.

David Nicholson has worked as an underwriter at Lloyd's of London since the 1980's. His interest in technology goes back many years including interactive mapping, apps, green tech, boats, solar and cars.