What do consumers think of smart charging? Perceptions among actual and potential plug-in electric vehicle adopters in the United Kingdom

Widespread adoption of Plug-in Electric Vehicles (PEVs) would add substantially to overall electricity demand, while increasing deployment of renewable supply sources will make supply-demand balancing more difficult. Early PEV market experience suggests that users preferentially charge their vehicles in the early evening, when other demands are high. Managed (or Smart) charging aims to shift PEV charging load to times when other demands are low, to facilitate better integration into the wider energy system, operation within network constraints, and minimisation of future network reinforcement costs. However, material effectiveness would require mass engagement with managed charging. To gain initial insight into the potential for managed charging, 60 semi-structured interviews were carried out with actual or potential UK PEV users. Interviews explored present charging behaviour and responses to two types of managed charging schemes, user-managed charging (UMC) based on time-of-use tariffs, and supplier-managed charging (SMC). Participants' willingness to engage with either was conditional on large reductions in charging costs. UMC was preferred over SMC, because of perceived personal control and lower perceived risk that a vehicle might not be fully charged at the required time. Preference for SMC was based mainly on perceived advantages to society as a whole.