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Service upgrades to the home, dual meters?

Discussion in 'Model S: Battery & Charging' started by aaronw, Feb 1, 2013.

  1. aaronw

    aaronw Member

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    I'm looking to upgrade the service panel on my home which is currently an ancient 100A unit for my Tesla model S which I hope to receive on 2/23. Anyway, it looks like the way for me to go is to switch to PG&E's E-9B rate. Doing so requires two meters. Has anyone else done this such that they have two meters, one for the house and the other for the car charger?

    I'm in the process of looking for what load centers are available that support this (if any) or how other people did this. I don't want to install two load centers since that would mean two things up on the roof. I plan to run 100A to my garage for charging but initially only put in a 15-50 outlet (with a 50A breaker).

    -Aaron
     
  2. Kleist

    Kleist Member

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    aaron - I have the same problem as you and need to upgrade my current panel from 100A to 200A with 100A going to the garage ( I am anticipating a second EV in the future ). PG&E has a nice estimator (PEV Calcluator) out there and with my driving requirement I don't see any advantage between E9B and E9A - both are TOU rates anyway. So I plan to go with single meter and E9A.
     
  3. geoffb

    geoffb New Member

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    Ok, here's the deal on E-9B. Hurry. PGE has applied to consolidate this rate in to a new plan, if you apply now by calling PG&E, you will be grandfathered in forever. I did this. After completing the application on the phone, you will receive a call from PG&E Engineering to discuss your pole-house drop, panel capacity, local 12kV feed capacity etc. I had 200A to the house, with 100A going to a sub panel on the garage, this panel feeds a 50A hot tub and 50A A/C unit. So, we upgraded the main home panel to 400A (at 80% Load Factor, that's 320A continuous). My electrician did this. PG&E Operations next comes out and strings a new pole-house drop, if needed. They found that the pole transformer was leaking and overheating, so we all were happy they changed that out too. They charge $100 for the second meter. Going from 4 Ga wiring from the Main panel to the Garage panel (100A) to 4/0 Ga for 200A (read the NEC section 516 on ampacity of conductors) was about $3K, as that circuit had to be in conduit, which needed changing out to a larger diameter. You wiring of course may be different. I must say, the folks at PG&E were VERY pleasant and most cooperative, they really did a fine job and could not have been more helpful. They said "we will do whatever it takes to make this work correctly". Excellent ! Expect the engineering of your circuit, survey by Ops and then the Field Division coming and doing the work to take 6 weeks.
     
  4. dmunjal

    dmunjal Member

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    How much did the electrician charge? I'm on the E9a. What good does the E9b provide? I asked PGE and they didn't seem to think it would make much difference. I have a Leaf and a Tesla and am easily in the highest tier. But I also have solar to compensate a bit.
     
  5. geoffb

    geoffb New Member

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    E-9B is 4% cheaper than E-9A. E-9A has the car combined with the house, E-9B is a separate meter. PG&E is correct, the difference is small. But since I had to add 100A to the sub panel on the Garage anyway, why not. The meter was $100 from PG&E, since I had to pull 75ft of 4/0 x 3 and increase the diameter of the conduit, it cost a bit. You can get a single load center in 200A or 400A capacity, one box.
     
  6. aaronw

    aaronw Member

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    In my case it looks like E-9B is noticeably cheaper. Currently I only have 100A load center on my house and I'd have to use the 30A dryer outlet in my garage for charging which is not located near the charging port on the model S (it would have been convenient if the charging port were in the front of the car).

    PG&E said that the drop from the pole is good for 200A though they didn't bother to come out for a site survey.

    The difference between E-9A and E-9B is not huge and it will take a couple of years to make up the difference.
     
  7. dennis

    dennis P85D

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    #7 dennis, Feb 2, 2013
    Last edited: Feb 2, 2013
    I went with E9A because I have roof mounted solar and as a result most of my net power usage is off-peak. By moving everything over to E9A all power usage from midnight-7AM gets reduced from $.30 to $.20 (max rate). Even though I used 3mWh to charge my Karma during 2012, my electric bill actually declined!
     
  8. chrisbrousseau

    chrisbrousseau New Member

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    I live on the Peninsula and just installed an E-9B meter in addition to the house E-1 rate, on separate panels, a 6KW solar system (two array, split between the panels), undergrounded utilities into the property, etc. We ran everything underground to a charging station in the front of the house with two separate circuits (100A for HPWC and a 50A NEMA 6-50 which I'm using now). geoffb's numbers are pretty close to what I saw, although for me this work was bundled with some other construction we were doing already. We decided it was better to lay the extra panel and meter since we were digging everything up anyway.
     

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