Obsession with numbers of EV chargers
There are quite a few articles appearing at the moment, which are focussing on which countries have more chargers than others. It seems a good country is the nearest to 1:1 ratio i.e. charger to EV. This comparrison is completely meaningless, as the figures do not include domestic chargers or the demographics of the country. a recent C40 report stated that there was no correlation between registrations and number of chargers.
Can I introduce the 'Herron' equation to try and bring some sense to the situation. I want to look at operational performance of two catagories: slow/fast and Rapid or AC vs DC. Starting with DC and specifically 50kW chargers. The ammount of power they can deliver is dependant on the car but in general a 50kW charger, will over an hour, deliver 25kWh of electricity which is 50% of its design capability. Now we need to know the availability so is is always maintained and ready for use. So lets say 95% of the day it is there in position, fully functioning and ready to be used or 0.95. The key now is the utilisation, lets say 2 cars per day for a total of 2 hrs which is about a 8% utilisation. so if we mutiply: 50% x 95% x 8% we get about 4%.
We can argue that the 50% is governed by the car so is a constant for all countries so lets just take availability and utilisation so 95% x 8% which is roughly 8%. Knowing the figure for a network in terms of operational performance is a much better comparator than simply sticking as many in as possible to get the best ratio published. So report operational performance as the success of the infrastructure.
In other words; if they are not being used stop putting more in as it simply reduces any chance of the current infrastructure being commercially viable. By all means reinforce hot spots.
With slow fast chargers if we have a car on all day it is fully utilised but if it only delivers 7kWh from a 3kW charger it is being used, I would suggest, for its parking spot, and would have a utilisation figure of 7%.
Principal Knowledge Lawyer (Energy, Transport & Infrastructure Projects) at Addleshaw Goddard
6 年Good point Colin. There needs to be clear instructions on how and when to charge. EVs don't come with detailed instructions on this. We are learning as we go along.
nextGenergy || EPCs | professional support to make properties energy efficient | reduced energy bills | other benefits
6 年Rapid hubs needed at hotspots, yes - hubs with a mix of chargers should be handier elsewhere, accompanied by the education (signage) about appropriateness of use (eg PHEVs that have just 3.5kw onboard chargers, ought not to use 43/50kw if 22kw fast charger available) - but some responsibility on OEMs to supply appropriate leads with their vehicles! Education is key.? Utilisation figures can be totally skewed, if the 'connected to a vehicle' time is considered vs the kWhs dispensed.? Have experienced far too often, in certain regions (notably Stirlingshire - Central Scotland!!!) being let down by non-functioning chargepoints and inappropriate use of Rapid Chargepoints by abandoned PHEVs left connected, driver absent, charge complete/in progress for half a day or longer!? Also driverless 75kWh cars (using 11kw from 43kw AC, when no adaptor has been purchased) taking a charge of half a day or more at locations where there is only 1 rapid chargepoint,? What does the BEV driver with a 22kWh battery do?? Who cares about the policing of such?? We are reliant on using the rapid chargers, as a rapid charge stop, on our transit journeys, as they were intended.? So many people I speak to, are reluctant to transition to electric for fear of not being able to get a charge when needed, and believing we do not have enough infrastructure in place.? Are we serious about the 2032/2040 aims in Scotland/UK?? Pros and cons of the Plug-In Car Grant changes from 12th November!
CEO & Founder at Boxergy
6 年Resilience is something that needs to be designed in. If you have a single unit, then trusting this is always going to be difficult. Having 2 units (almost) doubles reliability. By the time you get to 4 or more then you have a very high likelihood of one working.