You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
I disagree, it's not a garbage article, it's not nonsense, and it's largely true. A Tesla Model S can increase a home's instant electric load by up to 1000% or so in some cases. Many homes in California draw less than 10A @ 240V at any given point in the day or night. A single-charger model S will increase that instant load by 400%. A dual-charger Model S will increase it by 800%.
...
The numbers are real, but you and the MIT article, pick worst-case, low probability points to get attention. There are lots of big loads that people add. For example, a new steam unit in the shower. Steamist makes units up to 15kW and you can put multiple of these in for a large shower. Turn on all the burners in a new electric range for that big Thanksgiving meal and you can draw 15kW.
Most neighborhoods have just enough capacity in the local transformer because that saves the utility money, and in the end, keeps rates low. As the article points out, planning is what is needed. Offering incentives for the EV owner, like Time of Use (TOU), EV rates are a great start! This is a win-win. The utility knows more load is coming, and, as a part of their normal grid upgrade plan, put larger transformers in the right spots. The customer gets better rates for charging at low demand times, and thats better for the utility, also.
What I had not seen suggested before, is the concept of the utility controlling the EV demand with smart grid signaling. I have seen others suggest that the batteries in the EV be used to source as well as take power. Given the price of EV batteries and the concern over battery lifetime this seems to be a bad idea. However, allowing the utility to control the demand side by telling the car when to charge or not, seems like a great idea. For those times when the customer needs a charge NOW, you just need a priority button somewhere to force a max rate charge now. I have TOU electric water heaters at my house; on the side of each, there is a nice little red button to force heating of the water at peak rate times. I use this a couple of times a year when I have several guests over and they all shower after a day of skiing, biking, or hiking.
The article's main point about local demand is a valid one and it's why the distributor wants to know when somebody gets an electric vehicle with fast charging. They'll upgrade transformers as required. In fact, some utilities have already been upgrading local transformers based on predicted demand. PEV charging is unlike most other loads, with a large draw sustained for several hours. It's not any kind of catastrophic problem, just something that needs to be taken into account.
A Model S 85 kWh battery is sufficient to power my home for one day. I use approximately 28,000 kWh per year, which is just shy of 80 kWh per day. So from that perspective, if you need to fully charge an 85 kWh battery, it takes as much power as my house consumes in a 24 hour period.
Even if you boost to 4:1, you're still seeing a hefty increase: daytime average will be 5.33 kW, nighttime will be 1.33 kW. Add the 10 kW charging, and the 10.33 kW at night is still a 94% instantaneous increase over your average daytime load.
Model S doesn't usually require 10 kW all night, though. For average driving, a much smaller charge rate is sufficient (and/or charging at different times, with multiple EVs in the same neighborhood). I'm sure that as EV numbers increase, software support (with and without grid communication) will get more and more refined, in this direction.
I'll give you a real life example. I had my service upgraded from 150A (what the house was built with in 1996) to 200A.
I built a 75A OpenEVSE, for use with my Model S with dual chargers, I am already "not the average consumer"...
When I started charging at 75A, my voltage sag was huge, it would drop from 238V to 212-214V
I called my utility, multiple times to try and talk to someone about the issue, I finally received a call back from their engineering department months later. I explained I have an Electric Vehicle, it can present a 16-20 KW continuous load, and that I have a voltage sag issue.. They eventually sent out a lineman, who took a voltage measurement at the meter while I was charging, they finally believed me that either their transformer was undersized, or the conductor to the house where undersized.
They at first partially replaced the drop to my house (there are intermediate poles), this didn't help.
2 weeks later, they set a new pole next to the existing pole, I was wondering what they where up to (the high voltage cables in my town are scheduled to be replaced this fall, I figured they where replacing old worn out poles ahead of that)
That is partially the case, but one day on my way to work there where 3-4 trucks parked by my driveway, I pulled up with the Model S and of course they where all curious to see it, anyway, they tell me they are setting a new transformer today, just for my house, and my voltage issue should be solved... They ended up setting a 50KVA transformer, and it's only connected to my house (secondary wires only connect to my drop directly). I still am getting some voltage drop, from 238 down to 225V on the 75A load, but it's better than it was.. If they replaced that last 100' of undersized drop wire, sure it would be fine, but I don't want to push them too much, they have done quite a bit already.
The point is, the electric utilities will respond and fix the issues, but it takes them a long time, and they are only reactive to problems, not proactive upgrading things.
Back to the original topic, though -- the article is not a hit piece, and is absolutely the truth.
Understood, but I'll bet if you look at every TOU car that is set to charge at a certain time, it starts right around 12:00 am, whether 12:00, 12:05, or 12:30... I'll bet that with few exceptions, most people leave the default charge current at 40A, and Tesla won't change it because it doesn't want to be the first party responsible for someone's car not being charged fully in the morning. So whether you *can* charge at less than 10 kW, or you *can* charge at a different time, doesn't mean it will happen that way. it will aggregate and bunch at certain times.
Back to the original topic, though -- the article is not a hit piece, and is absolutely the truth.
But it is the same truth that happened when the utilities were behind the power curve reacting to air conditioner installs. Nothing new, and market penetration of EVs will happen at a rate that the utilities can react to. Even if that is a little slow, remember these are glacial electric utilities, not nimble high-tech startups.
Did the internet providers complain about having to upgrade their routers when thousands of new customers were asking for internet service?
The question at hand is local neighborhood grid and whether or not the transformer on the telephone pole outside my house is rated high enough to handle me and all my neighbors all went out and switched to EVs tomorrow and plugged in and all started charging at 80 amps in the middle of the day simultaneously while also running all of our central air conditioners. the answer to that is unquestionably no - we'd just blow the fuse on that transformer and then the power company would need to come out and put a higher rated one in and possible new lines of the old ones are enough to handle the load safely. That's it.
Speaking as a veteran of said timeframe and industry, the answer is yes, absolutely, unequivocally. And they did the same thing - they let them fail, then updated when necessary. Now, in some cases they had it even better, because they could do things like install BGP filters that allowed them to stretch the life of a router. You can't exactly do that with an electricity bus.
It will get there - one transformer failure at a time - at a significant convenience cost to a lot of neighborhoods.