UK grid capacity 'sufficient' for electric vehicles
Simulation studies indicate that a substantial rise in the number of electric and plug-in hybrid vehicles would have a much lower impact on the UK national power grid than was previously thought, though some local improvements might be needed.
The research study has been carried out by a consortium led by Jaguar-Land Rover as part of the Range Extended Hybrid Electric Vehicle (REHEV) project, which is part-funded by the Technology Strategy Board. Other consortium members are Ricardo, E.ON and Amberjac Projects.
The study marks completion of the first stage of the REHEV project and has focused on a range of vehicle charging scenarios and levels of market penetration to predict the likely increase in national energy use.
Four vehicle fleet charging scenarios were simulated, comprising uncontrolled domestic charging, uncontrolled off-peak domestic charging, 'smart' domestic charging and uncontrolled public charging throughout the day - for example, by commuters who recharge their vehicles while at work.
Charging was assumed to be single-phase AC as this is the most likely near-term solution, but the study also considered fast-charging scenarios, as for a large number of vehicles the energy demanded over a time period is likely to be the same and distributed evenly.
Assuming a 10 per cent market penetration of plug-in hybrid electric vehicles and pure electric vehicles in the UK vehicle parc, the study showed a daily peak increase in electricity demand of less than 2 per cent (approximately 1GW) for the scenario of uncontrolled domestic charging - the 'worst case' in terms of peak power demand. Other scenarios are less challenging: off-peak domestic charging, for example, increases electricity consumption throughout the night but has no impact on the peak daily demand.
The report points out that it will be a number of years before 10 per cent penetration could be achieved, and say that the national impact on grid capacity of such a significant electrification of the vehicle fleet would be manageable. However, the research team emphasise that local improvements may be necessary - for example, where local network capacity is marginal or where particularly high concentrations of electric or plug-in vehicles occur.
The project consortium is now looking at the timeline for reduced power station CO2 emissions, which would enable electric vehicles to claim true ultra-low-carbon status. Future reportswill look at fast-charging infrastructure, which would offer significant consumer benefits in the use of electric and plug-in hybrids.
The next stage of the REHEV project is the development of a modular electric and electric/diesel powertrain, suitable for several different vehicle types. This will initially be tested on a large premium sport utility platform.
Future passenger and commercial variants could have an all-electric range of over 20 miles, enough for most journeys. Longer trips would still be accommodated with the internal combustion engine, removing the range anxiety issues often associated with pure electric vehicles.