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CalGreen EV receptacle wired to apartment panelboard - rant

Y

Yikes

SAWHORSE
Joined
Nov 2, 2009
Messages
4,043
Location
Southern California
I've been working on a multifamily affordable housing development that is subject to 2022 CalGreen, and there's a requirement that 40% of parking spaces have EV receptacles that are wired directly back to the apartment's panelboard. This might be no big deal for townhomes with attached garages a few feet away, but for larger developments where the parking spaces are hundreds of feet from the units, the power loss even through large wires is significant, and the number of individual feeds running across the site from each apartment to each assigned stall is IMO inherently financially infeasible.


4.106.4.2.2 Multifamily Dwellings, Hotels and Motels
  1. EV ready parking spaces with receptacles.
    1. Hotels and motels. Forty (40) percent of the total number of parking spaces shall be equipped with low power Level 2 EV charging receptacles.
    2. Multifamily parking facilities. Forty (40) percent of the total number of parking spaces shall be equipped with low power Level 2 EV charging receptacles. EV charging receptacles required by this section shall be located in at least one assigned parking space per dwelling unit where assigned parking is provided but need not exceed forty (40) percent of the total number of assigned parking spaces provided on the site.
Exception: Areas of parking facilities served by parking lifts, including but not limited to automated mechanical-access open parking garages as defined in the California Building Code; or parking facilities otherwise incapable of supporting electric vehicle charging.
  1. Receptacle power source. EV charging receptacles in multifamily parking facilities shall be provided with a dedicated branch circuit connected to the dwelling unit's electrical panel, unless determined as infeasible by the project builder or designer and subject to concurrence of the local enforcing agency.
 
That last part of that section, about infeasibility, is what my firm has used on more than one occasion to get out of this requirement. Our engineers throw a fit over what you described (rightfully so) and the jurisdictions we work in are usually receptive to their argument.
 
I think the craziest part is they slipped some massive changes into the mid-cycle amendment. Usually, they save the big changes for the 3-year cycle but this time they added a lot of blue pages...
 
So this is going to sound off beat but I am currently working with a client that is looking for a cheaper way of installing ev chargers at the timeshare complex and be able to bill the tenant without installing major EV charger stations.

They are looking at these units which can be identified per node.

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Not fully in the loop more on the parking slots
 
mark handler said:
"...unless determined as infeasible..."
Click to expand...
Right. And "infeasible" in this case has no bright line definition.
It's totally subjective on the part of both the builder/designer AND the building official; and by extension, maybe also the electrical engineer, local utility, and (if applicable) utility consultant. And cost impact could be so big that it requires all if this coordination to occur well before commencement of construction documents, just to determine if the developer's pro forma is valid.

With that many contingencies, how is this code provision helpful in providing early guidance?
 
Yikes said:
With that many contingencies, how is this code provision helpful in providing early guidance?
Click to expand...
It leaves room for the reasonable person to make the call. If the developer/designer document a legitimate case for infeasibility, then a reasonable BO should accept it. If the code defined the line too clearly then a reasonable person would have a much harder time making the exception.
 
Yikes said:
EV charging receptacles in multifamily parking facilities shall be provided with a dedicated branch circuit connected to the dwelling unit's electrical panel, unless determined as infeasible . . .
Click to expand...
That language seems a bit too limiting. For example, if there are meter centers that support two breakers per meter, you could have one breaker supply a feeder to the dwelling unit, and the other breaker supply the EV charging receptacle in the parking area assigned to that dwelling unit. Or even with just a single breaker at the meter center, you might be able to route the feeder to a location where you can install a feeder tap to an OCPD to supply the EV charging receptacle.

Cheers, Wayne
 
There are smart receptacle solutions that allow receptacles on a house circuit to bill the power use to the tenant. But the prescriptive code as written does not allow for alternatives.
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mark handler said:
Ya know they could issue card reader access and charge the amount on the monthly bill, per unit number.
Click to expand...
Right, it's just that the code does not prescriptively allow this approach (using the "house" main panel instead of the individual apartment's panel). It is subject to the whim of the building official in their determination of "infeasible".
 
And by the way, even if using the house panel, the electrical infrastructure is still massive. From the same code section:
"Where low power Level 2 EV charging receptacles or Level 2 EV chargers are installed beyond the minimum required, an automatic load management system (ALMS) may be used to reduce the maximum required electrical capacity to each space served by the ALMS. The electrical system and any on-site distribution transformers shall have sufficient capacity to deliver at least 3.3 kW simultaneously to each EV charging station (EVCS) served by the ALMS. The branch circuit shall have a minimum capacity of 40 amperes, and installed EV chargers shall have a capacity of not less than 30 amperes."

Some quick math for an affordable apartment development with 150 apartments and 200 parking spaces (parking ratio of 1.33 spaces/unit)
(200 x 40% EV receptacles) + (200 x 10% Level 2 charges (from another part of the code) = 100 EVCS
100 EVCS x 3.3 kW/ 208 volts = 1587 amps load on the switchgear and transformers.
Now add to that the the load for the 150 apartments, which varies between 90-120 amps depending on unit size and features. Let's call it 100 amps unit or 1500 amps total, plus other house lighting and power (elevators, offices, site lighting, etc.). Now we're closing in on 3500-4000 amps.

But wait there's more: The state of California mandates solar PV, and our local utility (Edison) has required that the switchgear be sized for both the development demand and the PV supply. The state also is eventually pushing for ZNE. Now it's really getting huge.
 
Yikes said:
Some quick math for an affordable apartment development with 150 apartments and 200 parking spaces (parking ratio of 1.33 spaces/unit)
(200 x 40% EV receptacles) + (200 x 10% Level 2 charges (from another part of the code) = 100 EVCS
100 EVCS x 3.3 kW/ 208 volts = 1587 amps load on the switchgear and transformers.
Click to expand...
I don't see any language requiring 3.3 kW for the EV receptacles, just for the EVCS. So that computation is just 200 * 10% * 3.3 kW / 208V / sqrt(3) = 183A on a 208Y/120V 3 phase supply.

Edit: oops, the definition of EVCS is "One or more electric vehicle charging spaces served by EVSE or receptacle(s)." So the computation is 200 * 50% * 3.3 kW / 208V / sqrt(3) = 916A.

Yikes said:
Now add to that the the load for the 150 apartments, which varies between 90-120 amps depending on unit size and features. Let's call it 100 amps unit or 1500 amps total, plus other house lighting and power (elevators, offices, site lighting, etc.).
Click to expand...
That would be 15,000A (divided by sqrt(3)), but the NEC allows a 23% demand factor for 62 apartments or more. So if it is really 100A*208V =20.8 kW per apartment for total connected load (seems generous), that would be 100A * 150 apartment * 23% / sqrt(3) = 1992A.

Which would make the EV requirement less than a 10% increase in electrical load. Which would make the EV requirement almost a 50% increase in electrical load.

Cheers, Wayne
 
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P.S. Are the requirements of 4.106.4.2.2(1) "EV ready parking spaces with receptacles" and 4.106.4.2.2(2) "EV ready parking spaces with EV chargers" anywhere required to be separately satisfied? I.e. can one satisfy both by equipping 40% of the parking spaces with receptacles, 1/4 of which are supplied with EV chargers that plug into those receptacles? If so, that's a 20% reduction in the electrical requirement for EV charging.

Cheers, Wayne
 
So 40% of the apartments will have an EV charger tied to that apartment. Does that mean that the only people that are allowed to rent those so afflicted apartments shall own and operate an EV? If not, the requirement seems pointless.
 
Yikes said:
Right, it's just that the code does not prescriptively allow this approach (using the "house" main panel instead of the individual apartment's panel). It is subject to the whim of the building official in their determination of "infeasible".
Click to expand...
Alternate means and methods
 
I was hoping the white paper offered a mid scale solution that was similar to a public pay charge station without the management cost by third party
 
California state law (Civil Code section 1947.6) requires landlords to approve tenant requests to install EV charging stations in their dedicated parking spaces so long as the tenant is willing to pay for the charging station and associated costs, including installation and utility costs.
 
mark handler said:
California state law (Civil Code section 1947.6) requires landlords to approve tenant requests to install EV charging stations in their dedicated parking spaces so long as the tenant is willing to pay for the charging station and associated costs, including installation and utility costs.
Click to expand...
That is always applicable/ retro, whereas Yikes is speaking of new construction requirements...This is what they were trying to get into the base 2024 IECC which got beaten back to an appendix....It started at 100%

RE101.2.1​

New one- and two-family dwellings and townhouses with a designated attached or detached garage or other on-site private parking provided adjacent to the dwelling unitshall be provided with one EV capable, EV ready or EVSE space per dwelling unit. R-2 occupancies or allocated parking for R-2 occupancies in mixed-use buildings shall be provided with an EV capable space, EV ready space or EVSE space for 40 percent of the dwelling unitsor automobile parking spaces, whichever is less.
Exceptions:

  1. 1.Where the local electric distribution entity certifies in writing that it is not able to provide 100 percent of the necessary distribution capacity within 2 years after the estimated certificate of occupancy date, the required EV charging infrastructure shall be reduced based on the available existing electric distribution capacity.
  2. 2.Where substantiation is approvedthat meeting the requirements of Section RE101.2.5 will alter the local utility infrastructure design requirements on the utility side of the meter so as to increase the utility side cost to the builder or developer by more than $450 per dwelling unit.
 
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