Is your electric car as eco-friendly as you thought? Questions arise on energy sources to charge EVs

Countries where charging an electric vehicle is over 85% cleaner than driving a gasoline-powered car tend to be those with a consistent low-carbon energy supply source, namely hydroelectric or nuclear.

Electric vehicles (EVs) are a powerful weapon in the world's battle to beat global warming, yet their impact varies hugely from nation-to-nation and in some places they pollute more than gasoline models, data analysis shows. In Europe, where sales are rising the fastest in the world, EVs in Poland and Kosovo actually generate more carbon emissions because grids are so coal-reliant, according to the data compiled by research consultancy Radiant Energy Group (REG).

Elsewhere around Europe, however, the picture is better, though the relative carbon savings depend on what supplies grids and the time of day vehicles are charged. Best performers are nuclear and hydroelectric-powered Switzerland at 100% carbon savings vis-a-vis gasoline vehicles, Norway 98%, France 96%, Sweden 95% and Austria 93%, according to the study shared with Reuters.

Laggards are Cyprus at 4%, Serbia 15%, Estonia 35% and the Netherlands 37%. An EV driver in Europe's biggest car manufacturer Germany, which relies on a mix of renewables and coal, makes a 55% greenhouse gas saving, the data also showed.