Electric Vehicles: The Road to Grid Meltdown?
Will EVs really cause the grid to melt?
With a large uptake in the use of electric vehicles the potential is there to put an extreme, perhaps even overloading strain on the grid. Will it happen? Probably not. We take a look at the factors affecting the potential for grid "meltdown" and those that may affect your home too.
There is the potential to empty all the petrol stations if everyone decided they wanted to fill up at once, but it just doesn’t happen. Perhaps that is a slightly different example because you cannot fill up with petrol or diesel at home, but the principles will stand.
For example, there will be a proportion of people who have been charging at work during the day and do not need to plug in and the range of modern EVs is such that on average you only need to charge every four days or so – resulting in many fewer people plugging in as soon as they get home. The likelihood of everyone with an EV drawing maximum power from the grid at the same time is similar to everyone with a petrol or diesel car deciding to fill up at the same time; it's just not going to happen. Additionally, due to the supply chain for EVs the uptake is going to be gradual, so the electricity demand will not suddenly increase from one day to the next, because the uptake of EVs will be progressive, giving the grid time to learn and encourage recharging behaviours and have the ability to react appropriately.
Ok, so if we are fairly confident that it will not melt the grid, but could it melt your house? 85%-90% of all charging will be done at home (based on present charging patterns) but charging an EV is nothing like conventional home energy use. Take a kettle for example that draws 13A, but only for a couple of minutes. Charging an EV draws up to 32A and can do so for hours. With typical home cut-out fuses around 80-100A it may be possible that it could be tripped while charging an EV, having the kettle on and running an electric shower. If this is tripped, you have to get the DNO out to replace the fuse.
While this is possible, and more likely than melting the grid, there are studies underway, such as My Electric Avenue (link) and more recently Electric Nation (link), to understand the impacts of greater EV use both for the grid and the home. It is likely that policies will be put in place to encourage off-peak charging and, in parallel with this, smart charging control boxes (such as Esprit) to manage the home charging scenarios and regulate the demand of each household.