The Land Transport Authority (LTA) has decided to reduce the carbon emission factor of electric cars by 20 per cent, a move that is likely to improve the commercial viability of these exhaust-free vehicles slightly.

In an announcement yesterday, LTA said an emission factor for such vehicles will be fixed at 0.4g CO2/watt-hour - down from 0.5g currently.

This factor is to account for the carbon dioxide emitted during the production and distribution of electricity.

It will apply for the duration of the Vehicular Emissions Scheme - which rewards or penalises cars according to their carbon dioxide emission levels - from Jan 1 next year to Dec 31, 2019.

The factor of 0.4g will also be applied to the extended Carbon Emissions-based Vehicle Scheme from today to Dec 31 this year , LTA said.

The carbon dioxide factor has been a contentious issue among electric car advocates. They argue that no similar factor is taken into account for the production and distribution of petrol, diesel or natural gas.

There are only 132 plug-in hybrid cars, 12 electric cars and 18 electric vans in Singapore - or less than 0.1 per cent of the total vehicle population.

Christopher Tan