DCFC Economics: Small-Scale Public Access Fast Charging

[MyTH]

Most EV enthusiasts eagerly await the availability of improved charging infrastructure. A few of us try to pitch in and do something about it. Our family business has a small parking lot in the center of town, and we thought it would be a nice gesture to install a DC Fast Charger, devoting one parking space to public EV charging.

Have you thought about what it takes to purchase and install DCFC equipment? There are lots of details, like figuring out how to get your local electric utility to deliver the 3-phase 480 VAC input power you are probably going to need, but let's start with some options for the charging hardware itself:

DC Power Output​	Approximate Cost​
25 kW	$12,000
50 - 60 kW	$30,000
120 - 150 kW	$45,000
120+ kW with liquid-cooled CCS cable	$65,000

It's easy to look down your nose at the Bosch/Delta 25 kW DCFC units that many car dealers have. That's not really even a fast charger, right? So really, in order to be considered legitimate, you're looking at around $30k for the charging station (plus a bunch of site work and installation).

A year or two ago, a 50 kW charger seemed like plenty, given that the non-Tesla US EV market was dominated by the likes of the Chevy Bolt EV and the Nissan LEAF. Those vehicles could only charge at around 50 kW anyway, so why spend the money to put in a more powerful charging station? Today, the market has changed. It would be great to offer appropriate charging for the Mustang Mach-E and the F-150 Lightning. Since drivers of those vehicles would probably be disappointed with 50 kW, maybe it's worth an extra $15k to be able to offer them 120 kW charging, right?

Hold on, not so fast! In that price range, we're still looking at CCS1 charging cables that are limited to 200A. The Ford vehicles use 400V batteries, which may be at a somewhat lower voltage (350V?) when discharged. So, spending that extra $15k for the 120 kW charging station will only get you to around 70 kW (200A * 350V), if you're charging a Ford. Your fancy 120 kW station can get to 120 kW only by charging two vehicles at once or by charging at 600V or higher -- meaning the likes of Hyundai/Kia and Porsche. There aren't a whole lot of 800V vehicles on the road yet, and hitting the 120 kW only once or twice a month would incur higher demand charges on top of the higher purchase price and installation (bigger conduit, higher-gauge wire, bigger transformer, etc.).

Ford is a major EV player. If Ford were using an 800V architecture, it would make more sense to install a 120 kW charging station. As things stand, you'd have to go to a liquid-cooled CCS cable to reach 120 kW, which greatly increases the cost and requires additional maintenance. Much has been written about how vehicle manufacturers should go to 800V in order to reach charging speeds of around 350 kW -- and I guess that's true, with liquid-cooled charging cables that can handle 400-500A. Folks don't seem to realize the advantage of 800V in the low-end space, enabling 120 kW charging speed without the unwieldy thick or liquid-cooled cable.

This week, I'm grappling with a decision. Having been awarded a state grant to help with the first $30k (from the Massachusetts share of the VW Dieselgate settlement, same pot of money that started Electrify America), is it worth the extra out-of-pocket cost to install a more-powerful charging station, or do we settle for 50-60 kW?

- M

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[kltye]

It highly depends on where you're situated. In the center of town, I think a 200A CCS station should do the trick, especially if its uptime is close to 100%. Unless you're near a highway ramp, I don't see why anyone would need 350+ amp chargers. And this is coming from someone who depends entirely on public charging, since I don't have a garage that is electric-enabled.

Or, if you have a parking lot, you could spring for "fast" L2 charging - a 48 or 60A charger. I know with the MME, maxing out the 10.5kWh onboard charger is plenty fast for me, especially for public parking spots.

Correct me if I'm wrong, but the cost of 150kW+ chargers is only a small part of the monetary problem - those demand charges (I hear) can hit up to $1 per kWh, which means you're losing money if you get hit with those charges during a fast charge session.

In summary, I'd take a reliable, easily-accessible "low speed" DCFC over the likes of EA or EvGO with their barely 70% reliability in shady parts of town.

 

[Logal727]

Would it be better to just petition one of the big guys to install a station there? They’ve got the resources

 

[bshaw]

Is this intended to attract customers to your family business? Or you're just looking to dedicate some space to EV charging, and increase the number of DCFCs in your town?
Does that equipment you quoted include the network connection / point-of-sale interface to bill customers?

Agreed with @kltye above, you might consider a higher amp L2 charger, but I would guess that doesn't qualify for the grant money that is available.

 

[timbop]

The economics are certainly a factor that none of us can decide for you, but I would suggest that it greatly depends upon the "typical stay" a driver might make, which is based on what's around the location:

• If your location is somewhere like a beach spot or amusement park where people will stay for 4+ hours anyway, then multiple L2 chargers would be better. You could serve multiple users with much cheaper equipment, and no one is inconvenienced by the charge time so you'll get a lot of usage. DCFC with idle fees will actually be a detriment since people will have to stop what they're doing to come back and move their car.
• If you are near a theater other location where people stay for around 2 hours, then the 25 DCFC chargers will do the job and get lots of usage
• If the area is heavy shopping and sit-down dining where the typical stay is an hour, then 50kw will give plenty of "bang for the buck". Faster than that might be overkill, and slower might not be useful enough.
• If there's not a lot to do nearby and drivers are primarily stopping purely to get a charge, then 120kw would probably be the right choice. Any slower than that and people will move on to a 150kw or 350kw charger down the road fi they can find one. I wouldn't worry about 400V cars; clearly in the next couple of years 800V will be common

 

[Jimbo]

Agree with kltye, but I'll add that if lots of people will be driving *through* your town, the faster your charger, the more you'll compete (whether or not it's worth it for you economically...)

Personally, I only use public charging for road trips. A couple of my common destinations only have 50kw stations on the route. A 150kw would always get my business, even if it's a few miles extra driving.

 

[MyTH]

Thanks for the input! To clarify a few of those points...

Our location in Littleton, MA is right off an exit ramp from I-495. Nearly everybody going between New Hampshire, Maine, or eastern Canada and the rest of the USA drives through Littleton, so it qualifies as a major travel corridor. Also, there isn't much multi-family housing in the area right now, but a development of several hundred units is proposed for about 2 blocks away, creating a possible pool of local can't-charge-at-home users. For things to do while charging, there is a nearby CVS, a convenience store, a liquor store, and two restaurants, but not really anywhere people would stay for hours such as a beach.

When I started on this project a couple years ago, there were no DCFC stations in town, nor for about 20 miles in any direction. Last year, Tesla installed a 12-stall Supercharger less than a mile away (right next to the local theater). Once Tesla adds CCS plugs, that will be a great option too, which makes me feel less nervous about only having one parking space for EV charging. The "big guys" like Electrify America and EVgo aren't interested in our location because we only have the one parking space to offer. Flo is interested, but they're expensive (we'd have pay for the station, installation, and management).

There are existing Level 2 chargers nearby, including at the public library, at a Toyota dealer, and at a 99 restaurant. They're just standard 6.6 kW ChargePoint fare, but free for local residents -- so I'm not sure there would be much demand for another Level 2 charger.

My motivation is mostly to contribute to EV adoption, as opposed to promoting our real estate business; people don't buy a new home as they wait for their vehicle to charge. Still, having the charger might generate some "buzz". We could mention it in our ads and offer free charging for customers, along with a free Level 2 charging station or installation of a 220V outlet by a licensed electrician with every home purchased.

 

[AhardFSU]

That’s a tough call. In general I think that there is a lack of units in the 50kw for people that don’t have a charging solution at their home. If you’re that sort of user, you really shouldn’t be DCFCing your vehicle every week if you car about preserving your battery. So any help there could be beneficial, especially with speeds higher than the 6.6kw you’ll find at the local library or the Toyota dealership.

But on the other hand, bc of your location something over 50kw could make sense, especially without a EA or EVGo nearby. And there’s no telling when Tesla stations will enable CCS.

 

[dmastro]

As an property owner who has installed chargers for the public, I think your approximate install costs are extremely low. I recently installed 6 Chargepoint dual-charging L2 stations (12 charging points total) for a cost of approximately $170K (average cost of over $14K per station). In addition to the cost of the chargers, there is power upgrades, trenching and conduit runs, permitting, ADA site upgrades, etc... to consider. Thankfully we were able to make use of available grant funding to support EV infrastructure to cover a large portion of the installation cost.

As to the amenity aspect, L2 chargers are the most common here in California at shopping centers. If you're planning to offer complimentary charging, you can install several inexpensive Clipper Creek (or similar) chargers for the same cost as 1 DCFC. Owners will still be appreciative of the amenity, and will definitely like that fact that there are several chargers available as opposed to the single DCFC that's always occupied by somebody. Also as mentioned, for a neighborhood center, your patrons are likely local customers who don't need to stop for a full high-speed charge.

 

[dtbaker61]

Most EV enthusiasts eagerly await the availability of improved charging infrastructure. A few of us try to pitch in and do something about it. Our family business has a small parking lot in the center of town, and we thought it would be a nice gesture to install a DC Fast Charger, devoting one parking space to public EV charging.

If I were going to add charge stations to a private parking lot, I would go for LOTS of 7kw L2 for free or with 'suggested donation' signs. My hope would be that they would be seen as an Employee parking benefit, and/or encourage visitors to spend some time in the lot for nearby shopping or food or whatever your business is.

The town of Taos, NM put in 3 L2 chargers in the middle of town, and kept the cost down <$1000 each by not going big, and not trying to network and charge for metered charge. The whole idea is that people LOVE the special parking spot, and go shop or eat for a couple hours. Taos ski area put in 16 stations recently with the same idea.... prime parking spots to encourage EV owners to ski for the day and come back to a fully charged car.

Unless you are next to an interstate, and want to encourage fly-by fast charging? But then I think you ought to charge for it to defray cost of equipment.

 

[AKgrampy]

I am sure you probably brainstormed this but what negative aspects are there to just one spot? Will a queue affect parking? Will it cause negative feedback because people stop by and it is occupied? Negative feedback if it is down? Just some considerations. It just seems to me that single installations, not associated with a business, could be problematic. Maybe something like the Volta network would work in your case. They, if I understand correctly, make their money from advertising at the charger versus the sales of kWh. I do think an issue in the near future is the lack of chargers for apartment dwellers so a spot like your could become heavily used in the future.

 

[kltye]

Thanks for the input! To clarify a few of those points...

Our location in Littleton, MA is right off an exit ramp from I-495. Nearly everybody going between New Hampshire, Maine, or eastern Canada and the rest of the USA drives through Littleton, so it qualifies as a major travel corridor. Also, there isn't much multi-family housing in the area right now, but a development of several hundred units is proposed for about 2 blocks away, creating a possible pool of local can't-charge-at-home users. For things to do while charging, there is a nearby CVS, a convenience store, a liquor store, and two restaurants, but not really anywhere people would stay for hours such as a beach.

When I started on this project a couple years ago, there were no DCFC stations in town, nor for about 20 miles in any direction. Last year, Tesla installed a 12-stall Supercharger less than a mile away (right next to the local theater). Once Tesla adds CCS plugs, that will be a great option too, which makes me feel less nervous about only having one parking space for EV charging. The "big guys" like Electrify America and EVgo aren't interested in our location because we only have the one parking space to offer. Flo is interested, but they're expensive (we'd have pay for the station, installation, and management).

There are existing Level 2 chargers nearby, including at the public library, at a Toyota dealer, and at a 99 restaurant. They're just standard 6.6 kW ChargePoint fare, but free for local residents -- so I'm not sure there would be much demand for another Level 2 charger.

My motivation is mostly to contribute to EV adoption, as opposed to promoting our real estate business; people don't buy a new home as they wait for their vehicle to charge. Still, having the charger might generate some "buzz". We could mention it in our ads and offer free charging for customers, along with a free Level 2 charging station or installation of a 220V outlet by a licensed electrician with every home purchased.

Thanks for the clarification!

With regards to demand for another L2, those "6.6" kW stations barely put out 6kW a lot of times; I've seen the voltage sag all the way down to 200 volts at 31 amps at times. If you could put in a 240V (single phase) 48A charger, that would almost double the speed of those ChargePoint chargers, and put you within about half the speed of a 25kW DCFC, for a fraction of the cost.

Of course, checking off some boxes gets you attention, so saying you installed a DCFC is bound to get more attention. As with what most people said, faster DCFCs would get you more business for travelers going through town, but a standard 62.5kW station should be plenty to serve local residents.

 

[Cherlin]

The charging cabinet itself is probably one of the cheapest parts of the installation. My company does a lot of DC fast charging stations (on the utility side, setting the TX's and tying everything into the grid) and it's pretty common for the utility to spend $1,000,000+ on providing power for a medium size charging station. If you think about the sheer amount of energy being used, a bank of 4 chargers with 2-350KW and 2-150KW units you need 1,000KW of power potential at any given time. Typical TX loading is 80% which means you would be looking at a 1500KW TX (they don't really make 1200KW). Those used to be reserved for data centers or big malls, ETC. You would never see a TX like that in a small business park, which means the wires coming into the area aren't sized for that kind of load, so now you need to go back and pull in bigger wire from the nearest 600a primary junction, and now because the load is so great you are going to want a way to isolate that so now your installing a SW/INT/SW and programming the interrupter and getting that all installed.

All in your spending $600-800K on the grid side equipment, 200-300k on labor and 100K on design and permitting to install a 4 stall charging station. This stuff is crazy right now, and it will be years before that comes down (if it ever does)>

 

[iankellogg]

i personally really like the 50kw chargers. especially if im stopped shopping somewhere. 50kw over an hour is most of my battery and i dont feel like i need to constantly watch the charge incase i need to move my car.

 

[timbop]

Thanks for the input! To clarify a few of those points...

Our location in Littleton, MA is right off an exit ramp from I-495. Nearly everybody going between New Hampshire, Maine, or eastern Canada and the rest of the USA drives through Littleton, so it qualifies as a major travel corridor. Also, there isn't much multi-family housing in the area right now, but a development of several hundred units is proposed for about 2 blocks away, creating a possible pool of local can't-charge-at-home users. For things to do while charging, there is a nearby CVS, a convenience store, a liquor store, and two restaurants, but not really anywhere people would stay for hours such as a beach.

When I started on this project a couple years ago, there were no DCFC stations in town, nor for about 20 miles in any direction. Last year, Tesla installed a 12-stall Supercharger less than a mile away (right next to the local theater). Once Tesla adds CCS plugs, that will be a great option too, which makes me feel less nervous about only having one parking space for EV charging. The "big guys" like Electrify America and EVgo aren't interested in our location because we only have the one parking space to offer. Flo is interested, but they're expensive (we'd have pay for the station, installation, and management).

There are existing Level 2 chargers nearby, including at the public library, at a Toyota dealer, and at a 99 restaurant. They're just standard 6.6 kW ChargePoint fare, but free for local residents -- so I'm not sure there would be much demand for another Level 2 charger.

My motivation is mostly to contribute to EV adoption, as opposed to promoting our real estate business; people don't buy a new home as they wait for their vehicle to charge. Still, having the charger might generate some "buzz". We could mention it in our ads and offer free charging for customers, along with a free Level 2 charging station or installation of a 220V outlet by a licensed electrician with every home purchased.

OK, well for your situation I don't think a single L2 charger in your lot will get much use - not nearly enough to justify the effort and the expense. With just one spot, I don't know how much traffic you'll get from the highway even if you do 120kw - I certainly wouldn't rely on a single charger as my primary charging option while road tripping.

If your goal is to help your fellow townspeople - in particular the Multi-Unit housing going in - then maybe work with the developer to put public L2 charging in that parking lot? You probably don't want to lose your business parking spots, but perhaps offering to split or even cover the costs for several public L2 in the development in exchange for long-term advertising might be a win-win?

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