Will Electric Cars Break The Grid?
May 11th, 2016 by Michael Barnard
Running our automobiles on electricity instead of gasoline shifts energy requirements from gas pumps to the grid. What’s going to happen when significant numbers of cars are plugged in at night?
What’s the net? Electric cars aren’t going to break or even dent the grid. By 2021, global electrical consumption might increase by 0.16% to 1.5%. By 2040, things start to get interesting with 5% to 45% increases in global electrical consumption, but that increased demand is still a lot less than what we are putting in with renewables annually. There is no grid in the world today which will begin to struggle with likely penetration of electric cars by 2021.
In order to play out the scenarios, we need to know how many electric cars will be on the road, how far they will be driven, and how much electricity they will consume.
- I had already built a two-scenario model with what I believed were aggressive and more aggressive penetration rates. Tesla’s latest announcement merely makes the only aggressive target more likely. I built it to determine when gasoline consumption would start to fall due to electric cars — a long time, unfortunately — but it can also be used to estimate potential demand increases for electricity. According to the model, in 2021, there will be 25 to 50 million electric cars on the road globally of the over one billion cars that will be running at the time. That’s about 2.5% to 5%. Note that there are both less and more aggressive models out there that use different assumptions.
- Average distances driven vary globally, from the highest in the USA of 21,561 kilometres annually down to the European average which is around 12,800 annually.
- Electric car gas mileage equivalent ranges from about 22 to 35 kWh / 100 kilometres.
- Finally, many electric cars will still be second cars in 2021 but many won’t. For the purposes of this assessment, let’s assume from 50% to 90% of annual mileage by owners will be done in electric cars. Obviously, by 2040, the high end is more likely.
Given these assumptions, some simple math tells us that, in 2021, global annual electrical demand from electric cars would range from a low of 35 TWh to a high of about 340 TWh, with an average of 129 TWh.
Well, that’s not going to keep any utility managers up at night worrying about how they will meet the demand in the near term.
But electric car penetration will be uneven, so some locations will see higher numbers — California, Norway, and Japan being obvious examples. Higher penetrations will mean more electrical demand in specific geographies.
California currently is generating about 200 TWh of electricity annually and consuming about 260 TWh (it’s a net electricity importer). So California would see about an 8% rise in demand from electric cars in the extreme case. There is a lot of excess capacity on every grid and most of the demand will be at night, when there’s even more excess, so there won’t be any issues due to this at all. Electric cars won’t be increasing peak loads by more than a small fraction.
That increased demand is actually good news, though, as electrical demand is flat or falling outright due to efficiencies and continued shifts to post-industrial economies and rooftop solar in California is cutting into utilities’ revenues. Electrification of transportation is a rare good-news story for utilities, and one of the reasons why buying an electric car is systemically virtuous; decarbonization costs money and this gives utilities more money.
Projecting out further sees greater impacts. In 2040, the model suggests a 38% to 77% electric car penetration. That would be from 868 to 1,520 million electric vehicles on the road, consuming 1,200 to 10,000 TWh annually and an average of 4,100 TWH. At that point, we would see 5% to 45% of 2012 global electrical consumption flowing to cars, if overall generation stayed flat otherwise. Median penetration of electric cars but as primary vehicles is more likely in 2040, so using the 90% of miles being electric we see about 5,300 TWH or 23%. Those are more serious percentages.
However, it’s going to be fairly easy to keep up to that increased demand, as 115 GW of renewable capacity was put into operation globally in 2015, conservatively representing about 250 TWh of annual generation. If we keep hammering in renewables at exactly the same pace — a very conservative assumption as the growth rate continues to accelerate–, we would see about 6,000 TWh of additional annual generation from renewables by 2040, and the median demand from electric cars would consume about 87% of it. If instead renewables continue to grow, it would be reasonable to see 12,000 TWH or 18,000 TWH of new annual generation. At that top end, electric cars would consume about 30% of the new generation, leaving the remaining 70% to displace coal, which it would easily do with room to spare. Even at 12,000 TWH of new renewable generation, coal could be almost completely shut down with room for the electrification of transportation, an outcome much to be desired.
Electric cars aren’t going to break the grid. Anyone who says so isn’t doing the math.
Mea culpa: an earlier version of this article slipped a decimal place on KWH / 100 KM and understated consumption.
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