Understanding the challenges of electric vehicle charging

More and more people are making the move to electric vehicles (EVs), but this increased demand presents some challenges. Read our blog from Dr Colin Herron on the issues around Electric Vehicle charging.

While demand for electric vehicles has risen, the current approach of building more charging points isn't efficient. Dr Herron has explored the problems with the current approach, and how Newcastle University and Zero Carbon Futures are developing alternatives. 

What's the problem?

1. Increased charge posts will not increase EV registrations with private buyers.

The controlling factors are cost and availability. It will be 2025/26 before there is critical volume of EVs, including low-spec (cost) models, at comparable prices.

2. Nobody knows how many charge posts are required by type, location and when.

3. EVs as a percentage of market share means nothing.

4. The chargers we are installing aren't necessarily in the right place.

We need an EV charging infrastructure strategy

From the four statements above, it is clear that we need a more nuanced, evidence-based EV charging infrastructure strategy for the UK.

We have ideas and ambition, but we're missing the why and how. The Government's strategy at the moment is to spend money to meet the broad aim of providing more charging, but this is a blunt approach to a complex problem. 

It feels a little odd that the measure of a local authority's charging success is how many chargers are installed. Not, whether anybody is using them.

It is also bizarre that local authorities continue to install more chargers, but without really knowing the extent to which current chargers are being used.

Are we putting EV chargers in the right place?

After 2030, all cars sold in the UK will have a charging requirement of some sort. They will have to be plugged in somewhere.

The current approach to investing in charging results in significant numbers of charging posts being placed in council car parks.

This is no surprise. If a council wants to move up the ‘EV friendly league,’ then installing chargers on owned and managed land is a quick way to do it. But is that where drivers will want to use them?

In the case of petrol and diesel cars, we know where they need to refuel: 100% at a filling station. But an EV can charge in several places: home, work, destinations, filling stations and more.

We do not know the split of where drivers will charge their vehicles. And it's difficult to work that out, as most drivers have not yet lived with an EV so don't know where they will want to charge. 

Where should we put chargers?

Charging at home

Unfortunately, we lack any real understanding of both the demand and supply of charging.

We know that about 60% of homes have off-street parking. In the UK, this makes it about 18 million homes.

We also know that there are around 500,000 EVs now in use. Assuming those EVs are based at homes with off-street parking, then we have 17.5 million homes left to equip before overnight charging is a problem. While this presents a huge market for car dealers to tap into, it's a rough approximation.

What about people who want or have an EV now, and live without off-street parking? Where do they charge? As for supply of charging, how do we account for the growing number of charging hubs that replicate conventional filling stations?

Many supermarkets are installing chargers. As are workplaces and numerous council-owned car parks. In fact, there is so much infrastructure, much of it is not particularly used.

Our challenge then is that we simply do not know enough detail about who wants to charge, who is charging, and where and when they want to do this.

On street charging

What about putting chargers on the street?

If every home without off-street parking wanted to have an on-street charger, that would mean something in the order of 8 million chargers.

Do we really want 8 million chargers on our streets? Who will pay to have them installed and maintained?

It's not just about the chargers either. The UK government has released more money for street chargers, but the funding forces installation to take place at great speed. Can we keep up with the required Traffic Regulation Orders (TROs) to protect on street charging spaces for EVs? Without clear, robust regulations, petrol and diesel vehicles will be parked in the spaces.

Rapid charging: the 350kW 5 minute charging myth

Some believe that rapid charging is the answer.

Charging at home is likely people's preferred approach to charging. But if rapid charging stations mean it only takes a few minutes to fill up, then people can nip out to charge the car without too much disruption to their day - much like the trip to the petrol station.

But it is the car that determines the charge it takes, not the charger. If you put a Nissan Leaf on a 350kW charger it will take no more than 50kW. This applies to most EVs on the roads.

Longer charging times are inconvenient for drivers unless they are at home, or other periods where the car is parked for some time. Purporting the 5 minute charging myth is misleading and unhelpful.

What is required to develop an effective charging infrastructure strategy?

It might be possible to develop a model that can help inform EV charging infrastructure planning. But it will need to handle many different inputs/variables for the area to be studied.

To develop an effective strategy we need to develop detailed understanding through:

• geospatial modelling - what is happening where, with regards to charging? Where could this happen in the future?
• driver behaviours - times, routes and journey length
• technology updates - new battery tech, advances in power electronics, motors and drives
• supply chain - what will be available where? When?
• using data analytics and machine learning - to afford in-depth analysis

We're fortunate at Newcastle University, as we have world-class researchers working in all of these areas. That's one of the reasons why we moved Zero Carbon Futures into the University. 

Further reading