He said the extra peak demand in a smart world was an insignificant increase, but it could not be taken for granted that motorists would change their habits. The use of electric vehicles at off - peak times will lower demands on the UK energy system to 0.5 GW peak demand , compared to 3 GW if a predicted 10 million electric cars are charged during peak hours of 2 - 6 p.m. , according to a report from Aurora Energy Research . The research predicts that the number of electric cars on UK roads will grow from the current figure of 5 to 10 million by 2035 and 17 million by 2020 . The report suggests car owners be encouraged to use cheaper , off - peak tariffs or hand control of charging over to an energy company .
The use of electric vehicles at off - peak times will lower demands on the UK energy system to 0.5 GW peak demand , compared to 3 GW if a predicted 10 million electric cars are charged during peak hours of 2 - 6 p.m. , according to a report from Aurora Energy Research . The research predicts that the number of electric cars on UK roads will grow from the current figure of 5 to 10 million by 2035 and 17 million by 2020 . The report suggests car owners be encouraged to use cheaper , off - peak tariffs or hand control of charging over to an energy company .