Can grid cope with electric transport?

As electric cars appear more and more on our roads there are a flurry of articles casting doubt on whether the electricity grid can cope with the extra load. Having read quite a few of them it is clear the authors had never driven an electric car and they are treating the whole scenario as you would a petrol or diesel vehicle, whereas the method of driving and refuelling the vehicle is completely different.

Having used an electric car for five years, and just recently lost my home-charging facility, I have a better understanding as to how the whole user experience works.

The first thing to understand is that over half of all car journeys are less that 10km and a passenger car would typically spend 23 out of the 24 hours in a day parked.

This means even though a modern electric car would have a battery of 50 amp hours to 100AH, if the car is plugged in at home or at work, it would only have to recharge five to 10AH at a time.

It is very important to use an electric car in this way as sitting in a charging station for half an hour at a time is a real pain. It is envisaged that supermarkets would have charging stations so that drivers can plug their cars in and go do their shopping and, with a huge roof, a supermarket could be making electricity from solar panels and selling it at a good price.

People tend to forget that the whole of NZ is already wired for electricity and you can tricklecharge an electric car from the normal electric system in a house, with probably a special wire about the same size as used for a water heater or electric cooker.

Parts of the grid will have to be beefed up, but an important factor is that renewable energy is not centralised, as with a coal-fired power station, but is but spread right round the country. As an example of this, Northland is already self sufficient in renewable geothermal electricity and this paragraph from the Transpower plan, “In Northland, based on current connection enquiries, there is potentially up to 2GW of new renewable generation that could be built – enough renewable electricity to power up to 375,000 households”, shows power lines will have to be installed to export power, not import it.

Alsso, electric transport does not require a very big rise in the total amount of power needed, possibly only about a 10 per cent increase, and production of electric cars is starting slowly and it will take 20 years to convert the existing fleet of fossil-fuel-powered cars.

There is plenty of time to strengthen the grid and electric vehicles should bring down the cost of personal transport considerably but it might be a bumpy ride.