ESPcat Will The World End When Cars Go 100% EV?

At a recent New Year’s Eve party, while attempting to see how much sparkling wine I could actually drink, someone suggested that if New Zealand were to go all out for electric cars, there would be a huge impact on the national grid. I replied, somewhat unsteadily, that going 100% EV would be no problem at all. Secretly however, I did wonder if the grid could handle the load while also wondering if I had possibly already overloaded on wine. Now here I am, days later, wondering if I really should have consumed so much booze. Perhaps my judgement is faltering in old age. And what about the national grid? What happens when we go 100% electric?

I decided to go straight to Google and get the facts. I noticed right away that there have been many suggestions in the media that there is big trouble ahead for our struggling electricity supply system. Well it turns out that predictions made just 4 years ago were miles out. (1)

As the image above shows, predictions said we would be using much more electricity than we are actually using. So what about predictions of the effect of electric cars on the national grid? Are they way off also? It looks like they indeed are.

Here are some simple calculations showing that New Zealand’s infrastructure is well equipped to support a switch to EVs. In addition, the country saves $NZ 1 billion in fuel costs and cuts CO2 emissions in half. 

Total distance traveled on NZ roads is about 43 billion kilometers per year. (2) The average electric car uses around 15kWh/100 km. (3)

If we switch the entire New Zealand vehicle fleet to electric cars the total electric energy consumption would be: 43,000,000,000 km x 150 Wh/km = 6,450,000,000,000 Wh    or 6,450 gWh (gigawatt hours)

That sounds like a big number but it is only 16.5% of the annual energy generated on the national electricity grid. I included 1.5% to take into account the fact that trucks, while only 3% of the fleet, account for 7% of the km traveled and use 50% more fuel. A 16.5% increase is doodly-squat! It is only a bit more than the amount used by the Tiwai Point aluminium smelter. Yes that is the smelter that keeps threatening to close (actually Tiwai Point uses 13% of NZ’s electricity).(4) Yes electricity generation will have to be increased but only by a small amount each year.

Not only that but most people do their EV charging at night when is is simple and cheap to recharge. Peak electricity demand occurs between 4 and 8 PM so EV charging will have little effect on peak electricity demand. Only a few silly people use those daytime charging stations. So fear not, the national grid is completely stable and so am I after having several days to sober up from New Year’s calibrations.

Happy New Year all my blog buddies. 2021 is going to a great year for both electric cars and electric boats.

(1)https://theconversation.com/inaccurate-energy-forecasts-are-costing-us-the-earth-heres-why-42808

(2)https://figure.nz/chart/fLQioOzHx3ca2lzd

(3)https://www.energuide.be/en/questions-answers/how-much-power-does-an-electric-car-use/212/#:~:text=Most%20electric%20vehicles%20can%20cover,car%20reaches%2090%20%25%20and%20more

(4)https://www.stuff.co.nz/national/122113863/the-power-game-where-will-manapouris-electricity-go#:~:text=%5BFile%20photo%5D.,close%20the%20smelter%20next%20year