I don't think you have a good handle on how the distribution system is sized. Single, large loads like EVs at 10-30 kW were on nobody's radar even as recently as the 2010s. yes, infrastructure was designed for rising demand but not the sudden addition of 7 kW+ of capacity in multiple homes.
A typical EV charger draws anywhere from 7 kW to 25 kW. That is the total connected load of more than one typical North American house. And typical pole-mounted transformers are around 50 -200 kVA. Two EVs added to the regular mix is all it takes to upset the balance.
Unless you are talking about fast DC chargers, an EV's current draw is comparable to a households appliance, such as an electric range, dryer or furnace.
I'd be surprised to hear of a community with trunk lines that actually can't handle 1-2 EVs per house.
Still, that would be 20 times the average load on those homes, to charge a single vehicle. To move that power 100 feet, like from a busbar (I think, I'm not an electrician) to the charger would require a 3/0 AWG copper cable (which has a diameter of around 2 1/2", or 5.8mm). That cable costs around $2.59 a foot, or $259 to get power to that charger. That would be undersized, since I calculated it out at exactly capacity, and that price wouldn't include conduit (since the cable isn't direct burial) or installation.
Multiply that by three chargers, which I'd consider to be on the very low end of what a commercial installment would need, and you have quite a high demand for power. Five hundred amps at 480V is no joke. On the plus side, all this could spur adoption of renewable energy; with enough demand for power, investors will shovel money into renewable energy faster than it can even be used.
Re 1: The US built 1,000,000 new homes last year without anyone saying "how we the country cope with this increase in need for wood/etc". Most new homes will have multiple 50A circuits to power an electric range and/or HVAC system. Most level 2 electric car chargers max at 50-75A, and can be configured to only charge during times of low grid power demand. Every electric car in existence won't be DC fast charging all the time. In fact, I'd wager for most EV owners in the US today, DC fast charging is a very very low percent of their total charge allocation (between DC fast and AC level 2).
My EV charging, at 32A, draws more power than the rest of the house combined at peak load. The battery capacity is also equivalent to the house's max power usage for an entire day. Even when the low temperature is 90F/32C.
I hired an electrician to come out and install the 240V 50A circuit. I'm sure I could've, but our local code requires it, I don't want our insurer to deny our claim if something goes wrong. I, obviously, think people should be pretty careful with 10kW (or more) continuous load for hours at a time.
I definitely don't think people should lean on janky solutions that are technically feasible when it comes to EV power.
Not true at all. You can charge an EV at 5miles/hr on a standard 15A circuit, the same amount of power drawn by a hair dryer. You can generate that much power from 4 or 5 solar panels.
5 panels per EV deployed near where the EV charges will unburden the edges of power grid and not force any upgrades in the feed lines. High power charging stations are another matter, but the grid is sized for peak load, with a bit of coordination I don't see those being much of an issue either.
That's more related to the the calculation from my statement a bit back up the comment tree:
> it was about 43,000 GWh/y for CA (15m cars * .24 KWh/m * 12,000 annual miles). For reference CA has a yearly electricity generation capacity of just under 200k GWH/y.
But the numbers I posted that you're directly referring to are still important, as they indicate the need for improved electrical infrastructure for individual buildings who may want to put in chargers. Your grocery stores, apartments, motels, etc.
If just one 18kW charger can double demand on a motel's power, what happens when you add ten? Twenty?
A mere 6 fast chargers at 20% utilization would roughly double the electricity needs of a store.
Double.
Not to mention, we haven’t had to increase the capacity of our electric grid in decades (and it’s still falling down regularly), yet getting everyone in EVs quickly would increase the average need by a fair bit.
I did the calculations some time ago, and it was about 43,000 GWh/y for CA (15m cars * .24 KWh/m * 12,000 annual miles). For reference CA has a yearly electricity generation capacity of just under 200k GWH/y.
If you have enough 3-6kw chargers for everyone who wants to use one that stops being an issue. If a percentage of the cars are plugged in but done charging, that just means you can get away with a smaller grid connection and load share across the chargers.
Yes and no, 1200km charged in 10 mins is somewhere around 1MW of peak load. that's manageable and readily available using off the shelf distribution equipment, but it is a lot. The equipment is by no means cheap and large charging sites would almost always require upstream distribution and transmission upgrades, but this is something utilities are planning for. I suspect we'll also start to see on site energy storage to help offset the demand charges that these sites could see.
200+ A circuits in a residential home really makes a point for 400 V three phase (where the same load would be ok with a standard 63 A circuit, which is still a lot). [1]
However, when more and more people try to have fast chargers in their homes for EVs, then not only the residential installation poses a problem, but utilities would need to rebuild ~two layers of distribution to accomodate for a 100-200 % increase in residential power consumption.
[1] Not just because high currents are more difficult to handle properly, but also because you need a lot less copper.
Was having this conversation with a neighbour the other day.
I have a 7kw charger at my house, but the loop for our street is 21kw, which is typical here. It’s going to be a big problem to solve when it comes to it.
I wouldn’t mind if I had to charge at 3.3kw, but if every car is an EV the current grid just isn’t going to be able to carry enough juice.
> I've read the transformer problem is one that California utilities are already addressing, as in as few as one or two charging at night could blow out a neighborhood transformer.
Be very careful who you trust on these issues. A typical level 2 charger is 30 amps by 220 VDC. That's 6600 watts. That's the equivalent of four standard 120 VDC, 15 amp household circuits. If two people using level 2 chargers would blow out a neighborhood transformer, there are significant design flaws with the local infrastructure, and the utility company has set themselves up for failure.
I'm not saying the increase in the number of EVs charging at night won't cause any problems at all, but utilities are heavily regulated. They have to provide reasons for rate increases, and this looks like a honey pot for them. Expect them to shout about it at the top of their lungs.
I imagine we'll need pretty substantial upgrades to our electrical grid if we want electrical charging to be ubiquitous.
A typical home peaks at 15-30 kW, whereas a single DC fast charger can use as much as 62 kW or 500 kW.
Even a L2 charger uses something like 6.6-19.2 kW; if you tried to retrofit a Wal-Mart parking lot to have L2 chargers at every parking spot you'd probably need to build a new electrical power plant next door.
It's not always that simple - the electric lines have to support the load of additional vehicles. Even a relatively low charge rate of 12A (like a Volt) quickly exceeds the capacity of standard electrical wiring after about 3 vehicles. It's worse if you want higher speed charging, which requires 30A+ per connector. Adding the infrastructure to support more cables can actually be more expensive than running additional chargers, depending on how the lines were run.
"...we find that as little as 11% of heavy duty vehicles in Texas charging simultaneously can lead to significant voltage violations on the transmission network that compromise grid reliability. Furthermore, we find that just a few dozen EVs charging simultaneously can lead to voltage violations at the distribution level..."
A typical kitchen water-boiler uses 1.5kW. My EV, when charging at home, charges at 5kW.
If you have to do a fast charge because you’re on a road trip, you might choose to accelerate battery degradation by charging at 50-200kW, but that’s the rare and expensive exception to the rule.
What’s hard about national events is that historically power generation hasn’t been good at load following. If you know you’re going to charge 2 million EVs every night, there’s very little load following needed, it’s a steady load.
It’s still a lot more energy than current grids can supply, so there’s no doubt that more production and transmission is needed, but the engineering to achieve this is not some radical departure from current techniques.
Happy to see that someone actually did make some accurate calculations and found out with actual data that - even in a country where the main distribution lines are just fine and the "local" transformers and lines are modern/recent - the "last km" is/will be an issue.
Now imagine what would be the results of similar analysis in European cities (relatively densely inhabited, with an aged/aging infrastructure, a number of limitations for new lines and what not).
I mean, if you live in a solo or bifamily (or even very small condo's) house somewhere outside the city, or in a village, there will probably be less issues with upgrading the lines and transformers (at a cost), but for medium or large condo's in or near the city centre it will be impossible to provide enough power even for 7kW chargers when there will be many of them.
AFAIK here (Italy) a typical "local" transformer 20,000 to 380 V or 10,000 to 380V, it depends on the specific areas, is usually within the 300/400 kW range and serves 50-100 houses/apartments, each one having 3-4.5-6 kW contracts, and it is already near 100% use.
When/if each house (or anyway a recharge column for 1 car each) will want (or need) some 7 kW available, even if only at night, the amount of 380V electricity will be at the very least twice the current one.
Very likely the current infrastructure can bear an increase of 5-10%, maybe 15%, and as said this with only "slow" chargers.
A typical EV charger draws anywhere from 7 kW to 25 kW. That is the total connected load of more than one typical North American house. And typical pole-mounted transformers are around 50 -200 kVA. Two EVs added to the regular mix is all it takes to upset the balance.
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