What electric car owners do while we sleep could have profound implications for the grid and our energy use patterns and the practicability of electric cars. We covered electric vehicles in our book and its fair to say we have our doubts, not only since it would be nice to have less cars on the road but also due to the amount of extra generating capacity that might be required to feed the cars (amongst other concerns). One thing we did not consider except in passing was when people would charge their cars. This what an energy information company in the US has done with data from Tesla sports car owners. There are not a huge number of electric cars on the road but there are sufficient now to draw some tentative conclusions on how it might change our patterns of energy use if they do break through.
- The first is what electric car owners do while we sleep is use a lot more electricity than the rest of us to charge their cars. This is because they can get cheap rate electricity to do so.
- The second finding is that they are more likely to have solar PV.
- The third is that they use more electricity even during the day than other users who do not own electric cars. (They are more wealthy than those without so this might explain some of this difference).
The first and last findings are worrying. Its pretty obvious why people are charging their cars at night even if they have solar PV. Having spent a large amount on a car they are using it to drive to work (you can see their point). The author of the blog linked to above thinks this night time demand is not an issue, I beg to differ. The usage is much higher than for those without and the biggest peak of the Tesla owners day. In a traditional grid in which some capacity (such as nuclear) has to be keep running constantly. Some night time demand is therefore useful and in the UK is used for heating (night storage heaters) and to refill pumped storage schemes. But we are heading for a new type of grid with a large amount of renewables when their may or may not be excess power (these supply differences can be ironed out by energy storage but that is another issue). The problem is that based on the data given here if electric cars really take off, night time will become the time of peak electricity demand. This may or may not be manageable but its very different from the moment when we have a peak at breakfast time and the biggest peak in the evening (5pm) -at least in the UK. We could end up with three very large peaks in demand. The third slightly inexplicable finding was also worrying, could electric car use push up demand for electricity at other times? If this is true we would need even more grid capacity.
What electric car owners do while we sleep could be an issue for us all in the years to come as numbers increase. More research on energy use is urgently needed with electric car owners in different countries and different brands to see if the findings above are replicated.