The typical home built in the last 40 years has 200 amp service and so can draw up to 40 kW continuously. I've read the distribution grid is designed for an average load of 4 to 6 kW per home. Can anyone confirm this number?
Depending on the part of the US you live in many homes use a heat pump and in the winter when temperatures are low can draw up to 12 kW pretty much all night. I have seen this on my own home since my utility provided hourly usage data a couple of years ago. So that alone has got to come close to maxing out the local distribution grid. I guess I should contact my utility and ask them to what loads the distribution grid is designed.
So my question is what will EV charging at night do to stressing the distribution grid? At 32 amps a Tesla mobile cable will add 8 more kW to the above number making it 20 kW for some portion of the night or even all night if a full charge is needed. My car will charge at 72 amps or 17 kW, even more power than my furnace uses to heat the house from straight electricity.
Widespread adoption of TOU billing for car charging will get people charging at night, but that solves a different problem, daytime peak generation charges to the utility. They are always on a sort of TOU billing and have to pay top dollar for peak generation. But overloading of the local grid is a different matter entirely.
My concern is that the utilities are looking at the problem and will delay action so they can wait for it to become an "emergency", then get approval to implement plans that will be solely to their benefit and not very useful to EV owners. What seems ideal (but maybe not so practical) is for home EVSE (charging units) to be on the network so the utility can control them. When you want your car charged you get on the web site or use an app to indicate when you need the car and how much charge you want and the utility schedules the charging to keep the distribution grid balanced and meet your objectives.
This may be an ambitious project. But short of paying a bunch of money to the utility for them to beef up distribution, I don't see how we could even achieve 10% market penetration with home charged EVs without something like this.
Maybe I don't understand the distribution grid at all and there won't be a problem. But from what I've read, this will be a problem in less than 10 years and utilities aren't noted for being fleet of foot. If we don't do something to force action we may have some very onerous billing or operational changes jammed down our throats.
Depending on the part of the US you live in many homes use a heat pump and in the winter when temperatures are low can draw up to 12 kW pretty much all night. I have seen this on my own home since my utility provided hourly usage data a couple of years ago. So that alone has got to come close to maxing out the local distribution grid. I guess I should contact my utility and ask them to what loads the distribution grid is designed.
So my question is what will EV charging at night do to stressing the distribution grid? At 32 amps a Tesla mobile cable will add 8 more kW to the above number making it 20 kW for some portion of the night or even all night if a full charge is needed. My car will charge at 72 amps or 17 kW, even more power than my furnace uses to heat the house from straight electricity.
Widespread adoption of TOU billing for car charging will get people charging at night, but that solves a different problem, daytime peak generation charges to the utility. They are always on a sort of TOU billing and have to pay top dollar for peak generation. But overloading of the local grid is a different matter entirely.
My concern is that the utilities are looking at the problem and will delay action so they can wait for it to become an "emergency", then get approval to implement plans that will be solely to their benefit and not very useful to EV owners. What seems ideal (but maybe not so practical) is for home EVSE (charging units) to be on the network so the utility can control them. When you want your car charged you get on the web site or use an app to indicate when you need the car and how much charge you want and the utility schedules the charging to keep the distribution grid balanced and meet your objectives.
This may be an ambitious project. But short of paying a bunch of money to the utility for them to beef up distribution, I don't see how we could even achieve 10% market penetration with home charged EVs without something like this.
Maybe I don't understand the distribution grid at all and there won't be a problem. But from what I've read, this will be a problem in less than 10 years and utilities aren't noted for being fleet of foot. If we don't do something to force action we may have some very onerous billing or operational changes jammed down our throats.