A methodology for calculating the required number of rapid chargers for a population.
It is a frequently heard statement, especially in the press, that the UK suffers from a lack of electric vehicle charging infrastructure. This ‘lack of infrastructure’ is cited as being a major barrier to EV-uptake, creating range anxiety and making EVs unviable at the current time.
But exactly how many charge points are really required? And what type should they be to meet this increasing demand. I, and a colleague from Newcastle University, have discussed this for many months with the aim of answering these questions. How do we make sure that the UK has enough charging infrastructure – in the right locations – to change people’s mindsets about electric vehicles?
In undertaking this research, a number of data sources have been used to determine our conclusions. Starting with the number of ICE cars on the road and the number of miles driven, we are able to work out the energy required for a given number of vehicles.
We’ve looked specifically at the charging mix. At present, we have three options: (1) charging a home; (2) charging at work and (3) charging in transit – transit being either commuting or longer distances. We have made an assumption that many early adopters have access to home or work charging and therefore we have set a figure for charging in transit at 10% of overall mileage. We have also assumed that in transit charging will be provided by 50kW DC chargers for the foreseeable future as no cars currently available can charge at over 50kW. Time on a charger has to be factored in as does the various business models which are being tested on the public.
Our paper sets out the scenarios, with the required maths and experiments, and importantly it takes into account how an EV charges in terms of power taken from empty to charge.
So, what has the research revealed? The main point is that the number of rapid chargers does not need to be high, if they were 100% utilised. At present, they are very much under-utilised, mainly because they are either clustered together or in the wrong places, mainly due to the volume of Battery EV currently in the UK. At present, we have very good motorway coverage through Ecotricity’s Electric Highway however the reality is that there is still no fully national network. Some areas have no chargers at all with others being oversupplied. The A road system in particular, which carries must of the U, traffic, is not well served at all.
So how many do we actually need? The IEA methodology is one rapid charger per 130 cars and my method calculates one per 122 using a 30kWh Nissan LEAF as a datum (as the bestselling BEV in the UK).
The results explored in the paper should be important to any town, city or country moving to EV and I hope that they are the start of a wider discussion about the future of our charging infrastructure. Inevitably, it will be the public who will decide how they want to charge and over the next 5 years I will be working with operators to see quite what happens.
Download the full paper here: