‘Under the bonnet’ of EV car running costs
There was a LinkedIn post recently that raised the question of how the ongoing economic challenges might impact on the uptake of Electric Vehicles (EVs). As someone who has recently ‘done the right thing’ and bought an EV during 2022 (I eventually changed to a hybrid), the question aligned with my own recent analysis of my EV’s running cost. I have to first admit that I only undertook my analysis post purchase as at the time I was happily carried along by the wave of positive EV reviews, comforted by the rising sales (14% of all UK vehicle sales – October 2022) and concerned about the ongoing threat of rising diesel costs. Not to mention that I was safe in the knowledge I am also ‘doing my bit’ in mitigating the global climate emergency.
Like most people, my focus was on driving range, charge time, battery capacity. With EV propaganda still being published, I wondered if I should have paused to consider if running an EV is actually more cost-effective option to diesel?
Benchmarking the Comparison
My comparison is against a relatively new 2 litre diesel vehicle. I have chosen this vehicle for my real-life test scenario because 2/3rds of the test journey is at motorway speed and a larger capacity diesel offers optimum fuel economy. I could have used a smaller engine diesel which would provide larger mpg figures on shorter journeys but would overall, be less efficient on motorway. I’m therefore using this vehicle for the comparison as it would be this vehicle that the EV would need to provide a practical replacement and for most of us not living in the city, it reflects more likely use.
Comparison Journey
The test (comparison) journey is a regular commute of 60 miles round trip (there is no viable public transport alternative). The journey is 40 miles motorway and 20 miles urban. Driving frugally, an average fuel economy of 56 mpg is achieved with the diesel. With a regular spend of £40 at the fuel station, this provides 250 miles driving range (July 22) @ £9.60 real life costs per 60-mile commute (July 2022). This range and cost are based only upon the ‘typical’ combination of motorway and urban driving described and frequently undertaking this same journey.
Testing Period
The test was undertaken in July 2022 during warm summer months. The test was undertaken again during September and November.
Obtaining EV Performance Data
EV performance data was initially extracted from Pod Point (EV charger supplier)[1] and their vehicle real life vehicle performance assessments. It is not clear from their testing what the combination of urban rural driving they used or at what time of the year the testing took place. The diesel test vehicle is long term ownership. I hired and bought the other EV model used in the test and considered anecdotal feedback from other EV owners.
Temperature Impacts on Charging
In the absence of long-term test data, the impact of battery range performance during colder temperatures is difficult to assess with accuracy. Between each of the 3-test periods, my own EV suggests that it has 25% less range in October than during the warm summer estimates (July) as a result of temperature change.[2] It is assumed that this charge loss will increase as the temperatures continue to drop in the UK winter. A review online suggests loss of capacity up to 40% is not uncommon and is therefore a factor for consideration for up to 6 months of the year in the UK. A range adjustment factor of -25% has therefore been applied equally to all EVs assessed.
Comparison Results 1 (Home Charging)
The results of the comparison undertaken both pre and post October energy tariff change are presented for the sample selection of EVs. The results of the vehicle tested have been used within the performance estimations of the other vehicles considered. The comparison is based on the comparison journey adjusting for the 0.24pkwh October tariff change and £1.78 per litre for diesel.
July 2022
The performance table indicates that overall EVs are ‘cheaper’ to operate reaching savings of around 45% for some models in comparison to the diesel. An interesting observation is the disparity in EV performance across the test range suggesting that not all EVs perform as efficiently as each other. Clearly once charged, some EVs are able to make much more efficient use of their stored power.
October 2023
The test was repeated in October for the 0.31pkwh October tariff change and £1.96 per litre for diesel.
Based on current October costs, an EV will currently provide a saving of up to 35% to operate (down roughly 10% on September’s comparison). There is clearly a variation across vehicle ranges some models indicating they are now 14% more expensive to operate than the diesel test vehicle. From the sample examined, EV models suggest only marginal savings of around 20%.
Consideration of Charging Costs
The sole use of home 7kwh charging whilst minimising total charge costs, does not reflect real life use where charging on route or at destination using faster chargers is estimated to occur for 30% of charge cycles[3]. Charging whilst at work does make sense. Third-party chargers’ tariffs ranged from 0.42 pkwh for fast and 0.64pkwh for ultra-fast (September 2022) to 0.61pkwh and 0.74pkwh respectively (October 2022)[4]. Quicker charge times do increase cost by up 40% as evidenced in Pod Points April 2022 summary comparison noted below (£10.29 vs £6.55).
Free public chargers are clearly the optimal solution although their availability going forward is questionable given the current economic forecasts and popularity for use.
Based on a theoretical annual mileage of 10,000 miles and 30% use of third-party rapid chargers, the analysis by EV type was estimated using the October analysis comparison.
Comparison Results 2 (30% use of Third-Party Charging)
The results indicate that a few of the EVs identified in this test would match the annual operating costs of the diesel possibly providing a small overall saving. For those poorer performing EVs, the total operating costs is, for a few of the vehicles considered, actually greater than the diesel equivalent.
Practicality of Use
The comparison between vehicles presented in Comparison 1 is based on use of a 7kw home charger using both September and October 2022 prices. A 35% ‘running’ cost saving (for some models) is in my opinion not that beneficial when considered in conjunction with the real-life limitations of use which are dependent upon charge range, time and temperature. The operating costs are perhaps overlooked and secondary consideration by most drivers, myself included. For me, using an EV for a 60-mile round commute which is 90% of my EVs regular intended use does make sense.
However, as a family mode of transport and only vehicle upon which travel is dependent, living in the UK and out with a city, I would however need to think twice before switching to EV as the primary mode of private transport.
Further Reflections
EVs do indeed have a role to play. Hurtling around in a silent car with instant whoomph and no stop-start is novel. For me, as a negative consequence that I realised is that it does make shorter distances more attractive to undertake by private car as my mindset has changed. The negative consequence of environmental impact has been ‘mitigated’ and there is now a perception that the journey is both environmentally sound and financially ‘free’. The lack of mental ‘check and balance’ generated subconsciously due to regular petrol station visits is replaced with consequence free driving. However, having now done the calculation, I now know I’m now adding a minimum of £1,800 to my annual electricity bill (October) and shifting the balance of control from our fossil fuel driven economy to the big 6 energy suppliers….pause for thought!
Then of course there is the consideration of range vs. charge time that most people will naturally focus on. The results of my comparison indicate that you should consider your EV selection carefully to match the majority of journeys you undertake as clearly not all EVs perform comparably. An interesting finding that clearly is not marketed by manufacturers and I would assume not considered by buyers.
Test driving an EV to ensure it reflects your ‘typical’ journey and take note of the charge and the cost of operating as these factors cannot be gauged from the typical forecourt test drive and will be key consideration in how the EV will align with your lifestyle.
For me, whilst I enjoyed my EV I am glad that I didn’t buy it new and a have avoided the ‘front end’ price loading. As the majority of EVs are sold via company car purchases and incentivised by tax savings, it is clear how EVs have become so popular. EVs are undoubtedly a step in the ‘right direction’ but with so many unregulated and uncontrolled factors influencing their actual cost to operate, more could be done to make the ‘step’ a stride.
For me I will definitely be keeping a look out for the hydrogen fuelled cell versions which seems like the only real option to negate the external charging dependency.
[1] https://pod-point.com/guides/vehicles/
[2] No additional cabin equipment was operated and heaters etc remained off.
[3] https://energysavingtrust.org.uk/advice/electric-vehicles/
[4] Zap-Map Quarterly Price Index: Public Electric Car Charging Costs
