Battery Electric Vehicles (BEVs) can break our dependence on fossil fuels. Charging a BEV is comparable to connecting a whole new house to the electricity network. This could become problematic, particularly for electricity distribution networks, if charging of these cars coincide with each other or coincide with the existing peak electricity demand.
There is an inherent flexibility in the charging demand requirements of BEVs which could facilitate demand management strategies for optimal power system integration. Typically, cars are parked most of the time and the majority of daily driving would not exceed half of the vehicle’s battery capacity (advertised at 200km for typical BEV models circa 2017). The long parking time of the car, and the surplus battery capacity would allow flexibility in the time, duration and rate of charging and discharging of the car while still respecting the transportation needs of drivers.
A preliminary demand management strategy is to spatially spread the BEV charging demand. Consequently, this will also spread the demand in time. A study carried out by Newcastle University and based on actual BEV charging profiles, smart meter and network data demonstrated the benefits of such a strategy to mitigate the impacts on distribution networks and increase their hosting capacity to accommodate more BEVs. Spreading demand in space and time becomes possible by rolling out charging infrastructure to places where cars are routinely parked for a long period of time such as residential (off and on-street) and work locations.
Workplace charging becomes more than just a top-up location but a key location to enable BEV charging demand management strategies. In addition, rolling out an extensive charging infrastructure at both residential and workplace locations could facilitate the integration of renewable energy (e.g. from PV installations at workplaces). It would also open up opportunities for new demand response schemes to accommodate what could be the new biggest source of electricity demand. Has the race to own and operate this type of infrastructure started already?
Furthermore, charging infrastructure at residential and work locations need to allow charging and discharging control to fully tap into the flexibility potential of BEVs. This becomes possible using Vehicle to grid (V2G) technology that can shift the demand to avoid congestion of the electricity network, match demand with supply from renewable energy, and discharge the batteries to provide grid services such as frequency regulation or voltage support. The UK government is investing £30 million in 21 projects to support and overcome some of the challenges facing V2G technology. The National Centre for Energy Systems Integration is participating in two of these projects. As an example, the Nissan-led e4Future will examine technical and economic feasibility of V2G and will test consumers’ acceptance and willingness to offer their EVs to support the power system in exchange for lower bills.
V2G is the missing link that can facilitate the transition to low carbon and efficient transport and power systems. With proper grid integration strategies and coordination of efforts between transport and energy stakeholders, BEVs could become a network asset rather than a network problem.