The average emissions for an electric vehicle in the UK are 75 gCO2/km, when CO2 emissions at the power station are taken into account, according to an analysis by Gary Davis, Operations Director and chief greenhouse gas (GHG) analyst at Edinburgh-based carbon accounting firm Ecometrica.
This is lower than any other car in production, including the Toyota Prius (89 gCO2/km) and the VW Golf Bluemotion (99 gCO2/km) – two of the previously best-performing low-emission vehicles.
However, this figure is only correct for the UK, the company notes, as electric vehicle emissions calculated in this way are dependent on the electricity grid mixture of the specific country. Davis also calculated average emissions for France, Greece, the US, Canada and China. (see figure below).
|Electric car emissions by country charted against modern diesel and gasoline cars. Click to enlarge.|
Methodology. Davis firstly calculated electric car efficiency based on manufacturers’ range and battery capacity data for three electric cars; the Nissan Leaf, the Mitsubishi i-Miev and the Renault Fluenz.
He then took government data on the UK grid carbon intensity and applied this to the electric car efficiency. The grid carbon intensity calculations included not only the energy losses at the power station, but also the energy losses for transmission and distribution of the electricity across the UK electric grid.