A new report mapping out the utilisation of the UK’s charge points reveals the importance of ultra-rapid chargers to the electric vehicle infrastructure.

The measures highlight the increasing utilisation of ultra-rapid charge points

Launched to guide future charge point strategy and installations, the Green Finance Institute and Zapmap report is said to be a UK first. In particular, it will help investors and local authorities look beyond the number of charge points installed as a success metric and ensure the right charging devices are in the right place.

The work draws on Zapmap’s partnerships with UK charge point operators, which mean it’s able to record and analyse hundreds of thousands of charging sessions each month – from around 70% of all public charge points across the country.

Currently, there is no industry-standard definition or calculation for the utilisation of EV charging infrastructure in the UK, but the Green Finance Institute (GFI) and Zapmap have partnered for the report to introduce two effective ways to measure, understand and act upon utilisation rates.

First up is an exact time-based utilisation of charge points – or the amount of time a vehicle is plugged into a charging device, but not necessarily charging. It’s a useful way of understanding when a charger is available for someone to charge.

But the firms have also explored the estimated energy-based utilisation of charge points – in this case, the estimated energy delivered during a charging session, relative to the potential maximum energy that could have been supplied in the same period. This measure gives more direct insight into the revenue a charger could provide.

Thanks to Zapmap’s database stretching back to 2018, the two organisations have been able to reveal how these two measures differ, as well as how they vary across power ratings and have changed over time.

The overall picture sees time-based metrics showing higher utilisation at a relatively even level across power ratings, with energy-based metrics demonstrating a lower level of utilisation that varies significantly across power ratings.

While the number of fully electric cars on UK roads and charge point installations grew significantly between Q4 2021 and Q4 2022, the analysis found that the time-based utilisation of charge points across most power ratings did not change significantly during this period. On average, time-based utilisation increased from just under 14% in Q4 2021 to 15% in Q4 2022.

However, the analysis uncovered one exception to this trend, with the time-based utilisation of ultra-rapid chargers (100kW+) increasing from just over 12% to more than 16% over the same period. This shows that ultra-rapid chargers are in high demand, even with the number of these devices increasing by 78% between the end of 2021 and the end of 2022 – the highest percentage increase of any type of charger.

The two organisations also found that ultra-rapid chargers bucked the trend in terms of energy-based utilisation too. This measure of charge point utilisation demonstrates the estimated energy delivered during a charging session, relative to the potential maximum energy that could have been supplied in the same period.

While rapid chargers (25-99kW) showed an energy-based utilisation of 10.6% in Q4 2022, the same measure of utilisation saw their higher-powered, ultra-rapid counterparts sitting at just 4.4%.

As such, the analysis reveals a particularly wide gap between the two utilisation measures for ultra-rapid devices – 16.1% for time-based utilisation and 4.4% for energy-based. But this is chiefly explained by a commonly occurring difference between the max power rating of a charge point and the charging capabilities of the electric vehicle. In parallel, the ‘charging curve’ – in which electric vehicles only charge at peak rate for a proportion of the charge – also has an impact, as does the difference between advertised power and delivered power.

However, as the charging capability of electric cars, the charge point technology and the delivery of energy from the grid improves over time, the Green Finance Institute and Zapmap expect to see the difference between these two measures of utilisation start to decrease.

Melanie Shufflebotham, co-founder & COO at Zapmap, said the figures were important in turning the conversation from simply talking about the number of charge points to looking more closely at charging behaviour and patterns on different types of chargers.

“This in turn can help to inform local authorities and investment, ensuring the right charging provision is installed in the right places.

“As ever, new analysis often raises more questions than it answers. But one clear trend that both measures highlight is the increasing utilisation of ultra-rapid charge points, and an expectation that this will continue as more vehicles enter the market with improved charging capabilities.”

Jade Edwards, head of insights at Zapmap, added: “While there’s obviously no industry-standard definition or calculation for utilisation at present, it’s great to be able to put Zapmap data to good use, and work with GFI to produce reliable, credible information that will ultimately help to enable a smooth and fair transition to electric mobility across the country.”

The full paper from the Green Finance Institute and Zapmap is available here.