  Sales of new petrol and diesel passenger vehicles may not be permitted in the
United Kingdom (UK) post-2030. Should this happen, it is likely that vehicles
presently powered by hydrocarbons will be progressively replaced by Battery
Electric Vehicles (BEVs). This paper describes the use of mathematical
modelling, drawing on real time records of the UK electricity grid, to
investigate the likely performance of the grid when supplying power to a fleet
of up to 35 million BEVs. The model highlights the importance of understanding
how the grid will cope when powering a BEV fleet under conditions similar to
those experienced during an extended wind lull during the 3rd week of January
2017. Allowing a two-way flow of electricity between the BEVs and the grid,
known as the vehicle-to-grid (V2G) configuration, turns out to be of key
importance in minimising the need for additional gas turbine generation or
energy storage during wind lulls. This study has shown that with the use of
V2G, it should be possible to provide power to about 15 million BEVs with the
gas turbine capacity currently available. Without V2G, it is likely that the
current capacity of the gas turbines and associated gas infrastructure might be
overwhelmed by even a relatively small BEV fleet. Since it is anticipated that
80% of BEV owners will be able to park the vehicles at their residences,
widespread V2G will enable both the powering of residences when supply from the
grid is constrained and the charging of BEVs when supply is in excess. The
model shows that this configuration will maintain a constant load on the grid
and avoid the use of either expensive alternative storage or hydrogen obtained
by reforming methane. There should be no insuperable problem in providing power
to the 20% of BEV owners who do not have parking at their residences; their
power could come directly from the grid.
