Multi-family Level 1 or Level 2 infrastructure?

[wwarren]

L1 does not imply 120V outlet. It only implies 120V charging. J1772 L1 EVSEs do exist, although I must say that from a sturdiness point of view, I would expect a 120V outlet to do far better than a J1772 L1 station, and in the event of damage or just general wear and tear, it would be easier and cheaper to replace.

However, the Atlanta ordinance mentioned by the OP seems to only require "EV ready", not actual EVSE's or outlets, although it does require conduit, wiring and electrical capacity, the latter of which is probably what the OP is specifically concerned with: for the 40 spots, how much electrical capacity to install?

Yes, we would do a J1772 post mounted connector even for Level 1. The ordinance would allow us to put in only the infrastructure now, but we'd have to put in chargers later upon tenant request. The way we fund these projects doesn't provide for spending money later on like that. It would have to be done up-front. We also get an incentive of reducing the number of required parking spaces if we provide the connectors now.

 

[ai4px]

In the scheme of things wire is relatively cheap. Cheaper than trenching and cutting sidewalks. So maybe do L1 to the 40 park places but use one size up conduit so you can pull wires in later for L2. If the code says EV ready and doesn’t define that as L2, then why on earth would a developer spend the extra money? Shame on the city for not clarifying the requirement.

 

[wwarren]

An interesting comment from several of you has been to work with Chargepoint to limit access to tenants. I hadn't thought of that as being a possibility, so I'm going to look into that.

 

[wwarren]

In the scheme of things wire is relatively cheap. Cheaper than trenching and cutting sidewalks. So maybe do L1 to the 40 park places but use one size up conduit so you can pull wires in later for L2. If the code says EV ready and doesn’t define that as L2, then why on earth would a developer spend the extra money? Shame on the city for not clarifying the requirement.

Our construction folks would beg to differ on the wire. The difference in conduit cost to upsize would be minimal though, so that's a viable idea. Funding for affordable housing projects has strings that every allocated dollar must be spent. The question is what is the right thing to spend it on. Maybe we can do Level 1 with a better playground and a bike share program for the upcharge to Level 2. In other locations, we've worked with a supportive service provider to have a doctor or dentist come in for monthly wellness checkups. Maybe the cost to move to Level 2 would pay for that. Those are choices our developers and social workers get into as well.

 

[wwarren]

Why bother with the Tesla wall connectors at all? A Tesla will charge just fine from a J1772. The reverse is not true. You could run into a situation where you have vacant Tesla stations because nobody owns a Tesla, and you've taken away the opportunity for those that may have a used LEAF or Volt to be able to charge.

Frankly, I'm thinking of doing all Level 1 J1772, and maybe doing a handful of Level 2 just as a benefit to the community if we can find a good spot. Plugshare shows it's a bit of an underserved area.

 

[ralph142]

Frankly, I'm thinking of doing all Level 1 J1772, and maybe doing a handful of Level 2 just as a benefit to the community if we can find a good spot. Plugshare shows it's a bit of an underserved area.

That seems like a good option, I'm assuming the intent is that the infrastructure primarily facilitates resident use, rather than general use. I doubt many people eligible for affordable housing are driving model X's, and probably commuting reasonable distances, at least thats true here. So put a few L2 by the park, and most L1 in building parking lots. Future proof by running big conduit.

 

[mociaf9]

I'm a Tesla owner, and engineer with a real estate development company. We have an affordable housing development coming up in Atlanta across the street from a public park, where the city requires 20% of parking spaces must be built with infrastructure for EV charging, which in the case of this project will be 40 charge spots. There doesn't seem to be a mandate for what level of charging is required however. We are debating which to install. Level 1 would be less expensive to build than Level 2, but charges take longer. My thinking is that Level 1 charge times are OK for a parking lot meant for residential tenants. Level 2 chargers may cause problems by drawing non-tenants who want a bit of charge while visiting the adjacent park.

Thoughts?

Install NEMA 6-20 outlets. Those are 240V/20A and will be sufficient for ~80 miles of range on 6 hours of overnight charging. Plus the wiring and hardware costs will be limited. If you also included a 1or 2 serious EVSE in shared areas that will be sufficient for all uses. (If the electrical service for the parking area would be limited to 208V, this option starts to get marginal though.)

EDIT: I forgot to mention that the conduit installed should be capable of supporting a much higher powered line. I.e. the conduit should be large enough to support at least 60A even if the wiring isn't. That way you leave it with some future proofing.

 

[ai4px]

I'm reading the ordinance now.... it discusses raceways, 1" conduit and pull strings.... and planing for panel loads in the future, but stops short of requiring the actual equipment.... unless you are R-3. From the sound of your project it sounds like you are R-3... 101.9. (b) says All dwellings regulated by this section shall provide sufficient electrical capacity for a 40-ampere 240-volt branch circuit for the future installation of Electric Vehicle Supply Equipment.

So my question is.... can 20% (qty 40) of the parking spots be served by 40 feeders, 20feeders with shared EVSE, or 10 feeders with shared EVSE? Tesla HPWC can share a branch circuit with up to 4 units. If you determine the spirit of the code is that 20% of the parking spots must have a feeder to them, why in that case, I'd spread those puppies out to every other parking place or every 4th parking place. Using this philosophy you can serve 80% of the parking spots with a 40amp service to 20% of the parking places. (hope this makes sense).

This could get expensive really quickly depending on your interpretation... can you serivce 40 parking spaces with 10 feeders... or are you required to have 40 parking spaces have 40 feeders? If you are required to have 40 feeders for 40 parking spaces, it would be nice to stub up conduits to service 4 parking spaces around each of those 40 spots.... giving the possiblity of servicing 80% of the parking spaces.

 

[wwarren]

I'm reading the ordinance now.... it discusses raceways, 1" conduit and pull strings.... and planing for panel loads in the future, but stops short of requiring the actual equipment.... unless you are R-3 .

R3 is dormitories, fraternity houses, “congregant living” etc. R2 is multifamily apartments. All I have to do is infrastructure, but when a tenant asks for charging we would have to put it in. The way these projects are financed, we can’t defer something like that for later, so it has to be complete at the time of occupancy.

 

[wwarren]

ChargePoint can limit use to authorized residents. That may wind up being helpful.

 

[wwarren]

So my question is.... can 20% (qty 40) of the parking spots be served by 40 feeders, 20feeders with shared EVSE, or 10 feeders with shared EVSE? Tesla HPWC can share a branch circuit with up to 4 units.

Yes. From a city workbook FAQ
Q. With power sharing capabilities of today’s chargers, ie to install multiple chargers behind one breaker. Would this be sufficient for the ordinance as it would significantly reduce panel size and costs?
Example: 100 parking spaces = 20 parking space EV Ready Requirement. At 40 amps each, this would require an 800-amp panel. However, if you shared a 40-amp breaker and did power-sharing, would a 400-amp panel suffice?
A. Yes, if the equipment is approved for power sharing.

 

[Big Earl]

Yes. From a city workbook FAQ
Q. With power sharing capabilities of today’s chargers, ie to install multiple chargers behind one breaker. Would this be sufficient for the ordinance as it would significantly reduce panel size and costs?
Example: 100 parking spaces = 20 parking space EV Ready Requirement. At 40 amps each, this would require an 800-amp panel. However, if you shared a 40-amp breaker and did power-sharing, would a 400-amp panel suffice?
A. Yes, if the equipment is approved for power sharing.

Great. Power sharing units are absolutely the way to go. ChargePoint’s dual units can do power sharing and handle all of the billing and authorization. However, it usually involves monthly fees, which may not be in your budget.

 

[ai4px]

This may be "mcguiver-ish".... but I have an idea brewing in my head for limiting access to residents only..... ebay is brimming full of RFID locks. If you wired a power contactor up to be latching, you could use the RFID lock device's door contactor output to provide a pulse for say 30 seconds. If you wired it up in parallel with a current sensing relay it would stay on for the duration of the charging session. When the car stopped drawing more than 6amps (the minium for J1772), the current sense relay would drop the contactor. One such device is here https://www.amazon.com/Current-Sens...t=&hvlocphy=9011267&hvtargid=pla-660687002639

so recap....
1) Level 1 outlet is dead with a L1 EVSE plugged in.
2) user plugs J1772 into car
3) user swipes RFID badge near a reader and it sends a pulse to a relay for 30 seconds.
4) car begins to charge
5) As car draws more than 6amps, the current sense relay keeps the main contactor pulled in and thus power on the 120v outlet.
6) When car finishes charging, the current sense relay finally drops the contactor rendering the 120v outlet inert.

The caveat with this is that you have to program each RFID card to work with each reader in your parking lot. Also, it won't work with delayed charging... ie off peak at 9pm, car plugged in at 6pm.

If you provide the EVSE, then you'd be able to interrupt the CP signal on the J1772 cord and accomplish the same thing.

 

[ai4px]

Example: 100 parking spaces = 20 parking space EV Ready Requirement. At 40 amps each, this would require an 800-amp panel. However, if you shared a 40-amp breaker and did power-sharing, would a 400-amp panel suffice?
A. Yes, if the equipment is approved for power sharing.

So it would really be in your interest to find EVSE that shares 4 units. Like the Tesla HPWC. I think I've seen some clipper creeks that share 4... they were mounted 4 to a pedestal in the middle of 4 parking spaces in a grocery store.

 

[[email protected]]

I think that this is a good start. You might wish to have a handful of L2 stalls available at the outset for tenants who might need L2. Maybe 30 L1 with 10 L2 with the understanding that you will transition the L1 to L2 over a certain timeframe.

I am sure that there can be arrangements made with ChargePoint or other parties to have the equipment dedicated to tenants so that they can pay for the electricity that they use while excluding freeloaders who happen to spend some time across the street at the public park. Or you could have the charging stations and their apartment keys somehow connected. There has to be a way in 2019 to be able to match up EV charging with resident credentials.

cpa: Do you mind dropping me a PM at [email protected]? Thanks j

 

[ReddyLeaf]

Keep in mind, it's affordable housing. Plug-in hybrid would be the most I'd expect anyone to possibly have there for a few years until used electrics fall more in price.

Uh, a used Leaf can be had for less than $5000., probably close to $3000 in Atlanta. My rule of thumb for L1 vs L2 is can you get across the city AND back in less than 50 miles, in all weather. That mileage is about what a L1 will give you overnight. In Atlanta, I recommend L2, even if it’s only a 20 amp circuit. That will net you 30-40 KWh overnight, enough for 100-150 mi daily range. Better to have 40-amp, unshared, but at a minimum shared between two spaces. In my town, I’ve been living with L1 for eight years, but it’s just 20 mi across. In Atlanta, L1 just wouldn’t work. All this talk about sharing a 40-amp circuit makes me wonder about the exact wording of the requirements. If it’s not specific, what would keep a developer from sharing 2, 4, 8, 12, or even 40 spots on that 40amp circuit? You see the problem here? Change to EVs will be rapid. On a 20- 30-year time frame, it’s possible that essentially all tenants will have an EV.

It’s really a tough call to prioritize charging over better playgrounds, bicycles, vehicle sharing, or other amenities. All are needed. Yes, it would be awesome if everyone rode bicycles (I’ve been doing it for nearly 50 years), but come on, let’s be real, this is Atlanta.

Finally, let me just leave this thought: Do unto others as you’d like done to you. So, could you live with L1 charging day in/out, in all weather, ice/snow, pre-warning/cooling, probably in uncovered parking, with the inefficient charging overhead of certain EVs? Yes, it’s possible for some, but not for all. I really doubt that even 10% of folks can do it, for more than a few months.

 

[Watts_Up]

We have an affordable housing development coming up in Atlanta across the street from a public park,
where the city requires 20% of parking spaces must be built with infrastructure for EV charging,
which in the case of this project will be 40 charge spots.

I read the full thread but I think that the initial question is to clarify who and how the electricity and maintenance for the chargers will be paid ?

For a small building it would be possible:
- to have the building paying all the electricity cost and then collecting a charge fee from each user using an electric meter for each spot,
- or to have each user paying directly the electric utility company using their own home meter or a separate meter.

In your particular case, this will be a public parking providing a pool of sharable EV spots for tenants and visitors using the parking facility.
In this case it seems that the simplest way to handle the payments, would be to use an EV Charging company, like Plugshare or Chargepoint.

I would recommend to contact your local electric company to check if they might have a program with an EV charging company.
Typically the electricity company will install the required additional lines, and the EV charging company will deal with the installation and payments.

- Your only role would be to provide the parking locations, and to negotiate what would be the charging rate for the tenants and for the visitors.
- And the contractor company in charge of building the housing development, would perform the necessary work needed to connect the EV charging stations to the main electrical panel.

Note: A typical J1772 L2 EV charger providing about 5 kW seems to be the most appropriate solution for a pool of public charging parking lots.
- Typically those spots would be limited to 2 hours.

An L1 plug would be more appropriate for tenants who have their own dedicated parking spot and don't need to move after charging so they can charge all the night using Time-Of-Use rate.

 

[ai4px]

I read the full thread but I think that the initial question is to clarify who and how the electricity and maintenance for the chargers will be paid ?

For a small building it would be possible:
- to have the building paying all the electricity cost and then collecting a charge fee from each user using an electric meter for each spot,
- or to have each user paying directly the electric utility company using their own home meter or a separate meter.

In your particular case, this will be a public parking providing a pool of sharable EV spots for tenants and visitors using the parking facility.

You bring up an excellent point.... maintenance. You've got to charge something for use (even if the electric is free) because eventually they'll break. Case in point, the UN installed a bunch of water wells in Africa in the 1980s and now they're all broken because none of the locals can afford to fix them. On the 2nd round of these a private company is installing wells and pumps and charging something like a penny per liter for maintenance.

As for access, it seems the commercially available restrictive charging is SEMA or chargepoint and they'll take some off the top for the privilege. It has occured to that that you could homebrew a method to control access and require people using them to join the "EV car ammenity" just as some HoA's have a pool you join annually. Those costs could be used for maintenance and/or electric costs.

 

[yuhong]

I strongly disagree with the build-it-cheap&build-it-wrong myopic approach that the average person drives 40 miles. Nobody on the planet drives exactly 40 miles per day 365 days in a row for 20 years. And lots of people don't go home right after work, they go out to visit parents or see movies, and have to leave at 6 in the morning. Heaven forbid there is a traffic jam or holiday shopping or an emergency at a hospital 100 miles away or picking up a friend with a stuck car or an unexpected trip to the airport or lending the car to a spouse or ....

Averages in this case are worse than useless - they are dangerous and stupid. On average, only one person dies in a car crash, so let's put in only one seat belt. On average, you use only a few lights at a time, so let the house burn down if all the lights are turned on. Etc.

The OP was writing about a multi-decade wiring question, not whether one irrelevant anecdote about the non-existent average driver is doing this week.

The major advantage of distributed electric charging is that the wasted space of gas stations and wasted time going to them is eliminated. Why would anyone be encouraging people to use scarce public chargers?

On the other hand, I wonder how common block heaters are in Atlanta, given this is affordable housing.

 

[Rogue Synapse]

I agree that having Tesla HPWC, while beneficial from a load-sharing perspective, would be unnecessarily restrictive when Teslas can use the more universal J1772 just like everyone else. I personally think that abundant level 1 charging would be preferable to only a few level 2 chargers. I actually get the majority of my charging via level 1 and it works pretty well for me, though obviously there are times when I need to hit up a public level 2 charger or Supercharger to make certain trips work. If your car is plugged into level 1 whenever you’re not driving it, it’s actually remarkable how the charge adds up over the course of several days. This is less practical obviously for people with long commutes.