EV fast-charging comes to condos and apartments

https://arstechnica.com/cars/2024/04/ev-fast-charging-comes-to-condos-and-apartments/

by PaulHoule • 2 years ago

35 18 2 years ago

Rychard• 2 years ago

I wonder what the efficiency losses become in this configuration; using the grid to charge a battery to charge a vehicle.

A quick google query says that efficiency of L2 residential EV chargers is somewhere in the neighborhood of 85%, and for DC-DC chargers the efficiency is in the order of 90%. I don't know nearly enough about this to state anything definitively, but it sounds like the efficiency losses start to accumulate pretty quickly.

I wonder what the break-even point is in terms of cost compared to an average ICE vehicle.

Apply a healthy dose of "Don't let perfect be the enemy of good enough" of course, but I am curious about the economics at play.

Night_Thastus• 2 years ago

Considering ICE is less than 40% thermal efficiency of the fuel, I'd say it works out just fine.

But fast charging in general should only be used when there's no voice - it's a lot harder on the battery. Better to slow charge overnight.

travisb2• 2 years ago

It sounds like you almost have enough numbers to calculate the ball-park efficiency.

Grid -> condo battery ~85% (basically an L2 charger)

Condo battery -> L3 charger let's say ~96%[0] because it's a high discharge rate

L3 charger -> car ~90%

It's simple math now: 0.85 * 0.96 * 0.90 = ~74% end-to-end efficiency.

[0] https://www.researchgate.net/figure/Energy-efficiency-map-of...

immibis• 2 years ago

I don't think the efficiency can be partitioned like that. An L3 charger is supposed to output the same electricity that goes directly into the car's battery, with no additional conversion. An L1 or L2 charger has no conversion inside the charger - it's just a wire and a little electronic tag that says what the amperage is.

cogman103• 2 years ago

With something like this, throwing in solar makes a lot of sense (IMO). There are already batteries involved so you could use solar as the primary recharge mechanism with the grid as a backup.

lps41• 2 years ago

A single apartment complex could almost certainly not cover enough space with solar panels in order to charge a battery to accommodate this.

GenerWork• 2 years ago

I wonder how much the complex is charging for this, and whether people who have parking spots but don't have EVs also have to pay.

brewdad• 2 years ago

I'm sure they do. It's community owned property. You can't get out of paying for the condo swimming pool because you don't know how to swim.

turtlebits• 2 years ago

IMO, Fast charging is really only necessary for long trips.

Since L2 is more than enough to charge overnight, I'd rather see every parking space get a 30A 240V plug (which should be considerably cheaper than charging stations), with some shared metering to not overload the circuit, but also enough to fully charge all EVs overnight - essentially a single L2 charging station, that moderates load over a large number of plugs.

gpapilion• 2 years ago

This is the most reasonable solution as far as I’m concerned. There are still challenges related to this he electrical service the building is provided. For example you may find the building doesn’t really have enough energy to provide every spot L2 charging.

cogman103• 2 years ago

1 L3 spot doing 150kW translates to ~15 L2 spots or ~100 L1 spots.

For the same power distribution, an apartment complex could easily do several L2 spots and L1 for everything else.

With my 11 mile commute, L1 was almost viable (catching up on charge over the weekend).

If both work and apartments had L1, that'd be enough for most people commuting.

quickthrowman• 2 years ago

There are load management/load sharing products available for EV chargers today. Here’s a white paper from Eaton: https://www.eaton.com/content/dam/eaton/products/emobility/e...

h0l0cube2• 2 years ago

I'd rather see every parking space get a 30A 240V plug

The whole crux of TFA is that this isn’t feasible to retrofit to existing apartment complexes:

For many others, the parking spaces will be owned by the condo association or co-op, complicating the idea of giving each EV driver their own plug. Here, shared solutions make more sense, perhaps starting with one or two shared level 2 chargers as a pilot—often this won't even require extra work to the electrical panel. Costs are a little higher than for a home level 2 charger—between $7,500–$15,000 per charger, perhaps.
But for larger developments, scaling up level 2 chargers can quickly become prohibitively expensive. Older buildings may well need their electrical infrastructure to be upgraded, and running copper wiring across parking lots starts to add up fast.

ianburrell• 2 years ago

This battery-backed fast charger doesn't really help to charge the whole complex. How long does the battery last? What is the throughput?

Also, think of the trouble of trying to coordinate times and moving cars around. Everyone wants to charge in the morning, some people are smart enough to charge when get home. Nobody wants to get notification and go move their car in middle of dinner or breakfast.

I found a site with the cost, it is $58k for the battery-backed version. That pays for 5-10 level 2 chargers. Also, I'm not sure it changes the overall situation, cause either pay for wires, batteries, or time.

486sx33• 2 years ago

Everyone wants 60A minimum at 240v. But 30A is just fine, you’re home all night to charge anyway

EV fast-charging comes to condos and apartments

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