Managed charging to solve EV demand issue, says TRL

MC aims to shift plug-in vehicle (PiV) charging load to times - such as overnight - when other demands are low.

TRL found that, after experiencing some form of MC, the vast majority of people would be happy to switch to it.

This research, part of TRL’s Vehicles and Energy Integration (CVEI) project, set out to investigate the challenges and opportunities involved in transitioning to a low carbon fleet.  

The project provided mainstream consumers (petrol or diesel vehicle owners) with eight weeks of experience of using and charging a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV). These trials explored the consumers’ charging behaviour and response to approaches for the management of PiV charging demand.

Participants divided into the user-managed charging (UMC) charging group were incentivised to charge at times when electricity demand was low while those allocated to the supplier managed charging (SMC) group allowed the energy supplier to control the timing of the charge. Both groups were incentivised through a system where points earned from home charging could be converted to money at the end of the trial. A control group who did not experience MC were not incentivised to charge in a particular way but could earn these points by driving a minimum of 50 miles per week.

TRL’s report - Mainstream consumers' attitudes and behaviours under Managed Charging Schemes for BEVs and PHEVs – shows participants in the control group usually charged at home in the late afternoon/early evening (3pm-8pm). It reveals a peak in weekday charging between 5pm-6pm for PHEV participants and 6pm-7pm for BEV participants. At weekends, a greater share of charge events started earlier in the day. This shows that when charging is not managed, mainstream consumers are likely to charge in the early evening when other electricity demands are high.

Compared with unmanaged charging, the proportion of home charge events starting between 4pm-7pm was more than halved in the UMC and SMC groups. Most of the charging was shifted to later in the evening (UMC) or overnight (SMC).

Averaged across the groups, just under 90% of participants indicated that they would choose either UMC or SMC over unmanaged charging whether they had a PHEV or BEV.  

Dr Neale Kinnear, head of behavioural science at TRL, says: “We have generated an evidence base showing that managed charging is not only highly effective at shifting demand away from peak times, but it is also more appealing to the majority of mainstream consumers.”