Electric vehicles may not be as green as has been portrayed ("Many reasons to go electric" by Mr Sohindar Mohan Singh; Thursday).

While there are no direct carbon emissions when the vehicles are on the road, their carbon footprint can still be quite high, depending on the type of electricity that charges these vehicles. We could be merely transferring the carbon footprint from the vehicles to the power grids.

Unless we have sustainable energy creation such as solar or wind to power electric vehicles, there would not be significant reduction in carbon emissions by changing from engine vehicles to electric ones.

In addition, battery technology is not as developed as we wish it to be, and batteries last only a few years, unlike combustion engines that can last longer. This makes electric vehicles more expensive because of the need to change the batteries every few years.

The production of lithium-ion batteries also creates negative environmental impact. A 2013 United States Environmental Protection Agency report stated that lithium-ion batteries cause global warming, environmental pollution and negative human health impacts.

We are also creating more battery waste as we will need to change them every few years.

Costs associated with the recycling of lithium-ion batteries are extremely high, to the point that most of them end up in the landfill instead of recycling plants.

This means we will be dumping more and more batteries as we move towards a more electric city.

Unless battery technology improves and power grids rely on clean energy, switching to an electric vehicle would not reduce carbon emissions as much as we hope it would.

Ng Chee Siang