The grid in UK grid has assured to cope with plug-in hybrids
A survey was conducted and it was found that the UK’s electricity supply system and national grid has the capacity to deal with an increase in electric and plug-in hybrid vehicles.
The every day peak-use increase is expected to be less than 2%. This is measured under the assumption that electric and plug-in vehicles account for 10% of all vehicles on Britain’s roads.

The Range-Extended Hybrid Electric Vehicle (REHEV) development team is the ones who conducted the survey. They were able to get their data from Ricardo and Jaguar-Land Rover.
The team has proposed that some minor local upgrading to the electricity supply infrastructure may have to be carried out. But as such the national system is sufficient for the short and medium term.
The REHEV team is presently functioning on a standard, flexible policy for an electric and diesel-electric vehicle.