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  • 4.48kW system coming online in SF Bay Area (San Ramon)

    Learned a lot from the group here from the past a few months.
    Gathered quotes from half a dozen installers (all with 5 star yelp rating) and chose the lowest price one. (The quoted rates received from various vendors are between $3.3 and $5.83/Wdc).
    One vendor lower the quote from $4.7 to $3.7/Wdc after seening others quote. But I did not choose them. It shows the range of possible cost for your reference.
    Since I was asked in PM but can't respond with PM (less than 10 posts), I will address here: The installer I went with was the same as the one mentioned in the "7.56kW system in Dublin" thread.

    Signed contract 9/4
    Installation occurred 9/15-9/16
    City inspector came once during installation (9/15), and then twice after the final installation (9/21 and 9/22) to resolve warning label applied to conduits/panels and then signed off the final permit.
    While waiting for PGE to turn on net metering, the system is generating electricity.

    System Spec
    16x SolarWorld SW280 Mono black panels
    1x SMA SB5000TL-US-22 string inverter - 10 years warranty (including SWDM-US-10 Web Connect and SMA Secure Power Supply outlet)

    I decided to go with SMA instead of the Enphsae micro-inverter primiarly based on the lack of real world history for the Enphase.
    My system set up have 6 panels facing East and 10 panels facing West. Neither side have shade issues. The SMA has 2 trackers so each one can handle the panels on one orientation nicely.

    SMA's web monitoring interface is sufficient for me. After a few days constantly checking the display on the unit as well as on the web page, i am already starting to get bored and checked less frequent.
    The energy production is right around (or just a little bit higher than) the PVWatts estimation. So I am happy with the system design (which in hindsight isn't that tricky, especially for simple systems like mine).


    Total (pre-tax credit) $14,784 --> That's about $3.3/Wdc

    Hope I made the right choice.

    SMA sunny portal.jpg

  • #2
    Originally posted by dshenmdyn View Post
    Learned a lot from the group here from the past a few months.
    Gathered quotes from half a dozen installers (all with 5 star yelp rating) and chose the lowest price one. (The quoted rates received from various vendors are between $3.3 and $5.83/Wdc).
    One vendor lower the quote from $4.7 to $3.7/Wdc after seening others quote. But I did not choose them. It shows the range of possible cost for your reference.
    Since I was asked in PM but can't respond with PM (less than 10 posts), I will address here: The installer I went with was the same as the one mentioned in the "7.56kW system in Dublin" thread.

    Signed contract 9/4
    Installation occurred 9/15-9/16
    City inspector came once during installation (9/15), and then twice after the final installation (9/21 and 9/22) to resolve warning label applied to conduits/panels and then signed off the final permit.
    While waiting for PGE to turn on net metering, the system is generating electricity.

    System Spec
    16x SolarWorld SW280 Mono black panels
    1x SMA SB5000TL-US-22 string inverter - 10 years warranty (including SWDM-US-10 Web Connect and SMA Secure Power Supply outlet)

    I decided to go with SMA instead of the Enphsae micro-inverter primiarly based on the lack of real world history for the Enphase.
    My system set up have 6 panels facing East and 10 panels facing West. Neither side have shade issues. The SMA has 2 trackers so each one can handle the panels on one orientation nicely.

    SMA's web monitoring interface is sufficient for me. After a few days constantly checking the display on the unit as well as on the web page, i am already starting to get bored and checked less frequent.
    The energy production is right around (or just a little bit higher than) the PVWatts estimation. So I am happy with the system design (which in hindsight isn't that tricky, especially for simple systems like mine).


    Total (pre-tax credit) $14,784 --> That's about $3.3/Wdc

    Hope I made the right choice.

    [ATTACH]7807[/ATTACH]
    Congrats. Yours got installed 1 week before I am... Now I know where that guy went while doing the installation on 9/21 and 9/22 at my home and why the inspector does not surprise to see him during the 9/22 middle job inspection.

    Comment


    • #3
      solar_newbie, is your system up running? how do you like it?

      Observing pretty much the entire installation process, I would say the solar electrical part isn't that complicated. The device manufacturers have made the inter-connect so easy and they are almost plug-and-play. Given today's automated manufacturing process, I would expect pretty high process control and unit to unit consistencies. Based on that, I would say the chance of failure of the components (the panel, the inverters, etc.) is probably lower than the chance of mistakes being made during the installation process itself by the crew. That's the reason I did not place much emphasis on annual production guarantee. My thinking is if the failure is caused by the mistakes made by the installation crew, then it would be pretty obvious (i.e. system not going to turn on or something like that). It won't be subtle changes in annual production level. But that's my theory.

      The experiences of the installers are most beneficial when doing the planning (arranging the positioning of the panels, the conduits, etc.) and doing the standard electrician job. That helps to save time on the job by avoid making mistakes and having to take things apart to fix issues. Those are the things I can't do nicely myself.

      In my day job, I have been tuned to look out for risks (failure analysis). Since I don't know how much margin the standard roofing techniques have, I cringed as I watched the crew working on the roof, drilling, hammering to find the trestle and putting in flashing. That's the same as I would cringe when watching the surgeon operates on someone. I have to assume it must be pretty generous giving the type of labor force in that field, the training they would have, and the limitations in quality control that can be put in place through out the job, i.e. it would be very difficult for to do a quality inspection AFTER the roof is put up

      Regardless of whichever installer does the job, I am sure I will watch out for leaks through this and the next a few winter seasons to make sure everything up there is all right.

      Comment


      • #4
        I would say I can do the installation if it is on the rack. Electrical is very simple ... I can do it and will be much better than any of those installers. I have to corrected them couple times and requested different adjustment.
        The only part is to work on the roof and work on the main panel where you can not turn if off (Main panel connect directly to the meter via 200A wire).

        I would say they have both Solar and Electrical License. They can do many different things that most of solar installers can not be done. Like changing electric system on the way to make better adjustment.
        My original plan was to install 60A breaker to replace with the 40A AC breaker and move the 40A AC breaker to the Solar subpanel. So, subpanel will have 60A and I have to share the EV charger with my AC. I might not be able to turn them on the same time. Plus, I will use all 8 slots (4 double breakers) on the subpanel and make the electric wiring looks bad.

        They can adjust with a dual breakers : 30A+50A and put the AC into 50A and Solar into 30A. Normal Solar installer will stop there. However, I do not comfortable to have 30A for my solar sub-panel since I want to add EV car charger and might use for some additional load in the future. Plus, I might upgrade my AC to bigger one in the future (My current AC use max 25A -- Suggest to have min 30A breaker).

        I asked them to change to a different breaker and things just change right away since it made sense... to get 40A for AC and 50A for Solar subpanel. My friend told me that most of solar installers will need to call back sub-contract electrician to do such change and will charge extra as you can not turn off the main panel ... everything must done with live electric. And I will not want to do any work on that Main Panel myself. I can play with any sub-panel since I can disconnect them from main panel.

        The roof is the most scare part . My array must be moved 3 feet after first middle job inspection. Inspector wants to make sure there are 3 feets space on both sides of the arrays without anything there. There are 2 holes and installer put metal sheet to seal it under shingle. I need to watch out the next few years.

        Comment


        • #5
          Received PGE Proof to Operate confirmation in a week

          The installer applied with PGE a day after the permit was signed off last Tue. Just received email from PGE that the system is officially approved for interconnect and net metering is ON. It took just a week.

          Too bad it rains today


          I am sure it will generate plenty electricity throughout the year to cover most (if not all) of my usage including an EV.

          Comment


          • #6
            Originally posted by dshenmdyn View Post
            The installer applied with PGE a day after the permit was signed off last Tue. Just received email from PGE that the system is officially approved for interconnect and net metering is ON. It took just a week.

            Too bad it rains today


            I am sure it will generate plenty electricity throughout the year to cover most (if not all) of my usage including an EV.
            Congrats. That is fast from PG&E.
            Mine needs to wait for few days to get special label per city inspector request. The inspector is good and check every single things from roof to bottom, but too hard

            I got my new EV car also .... Can't wait to connect to the grid to save those charges...

            Comment


            • #7
              You will be online too in no time. Good luck!

              Comment


              • #8
                My system was turned on last Tuesday but here in Fremont they require those special stickers too and Barukh had to order them since he ran out..

                He came back on Friday to have everything properly labelled and inspector finally had time to come over yesterday morning to sign off on the system..

                Now I am waiting for PG&E to approve the NEM application..good to know it shouldn't take more than a week..

                Comment


                • #9
                  Congratulations in getting your permit signed.

                  Once he put in the request to PGE, you will start to get PGE emails notifying you the progress of the application. That was a pleasant surprise as I do want to know where things are with PGE.

                  Make sure you read through the PGE emails as I found him accidentally put in an incorrect rate plan request for me.
                  (I had E-1 and switched to EV-A effective Sept 1. So when I give him my previous PGE bill from Aug, it still shows E-1. He was confused by this and incorrectly put E-1 in the PGE application for solar.
                  I called/texted him after I noticed the problem and he fixed right away.)



                  Originally posted by justthinking View Post
                  My system was turned on last Tuesday but here in Fremont they require those special stickers too and Barukh had to order them since he ran out..

                  He came back on Friday to have everything properly labelled and inspector finally had time to come over yesterday morning to sign off on the system..

                  Now I am waiting for PG&E to approve the NEM application..good to know it shouldn't take more than a week..

                  Comment


                  • #10
                    Originally posted by dshenmdyn View Post
                    Congratulations in getting your permit signed.

                    Once he put in the request to PGE, you will start to get PGE emails notifying you the progress of the application. That was a pleasant surprise as I do want to know where things are with PGE.

                    Make sure you read through the PGE emails as I found him accidentally put in an incorrect rate plan request for me.
                    (I had E-1 and switched to EV-A effective Sept 1. So when I give him my previous PGE bill from Aug, it still shows E-1. He was confused by this and incorrectly put E-1 in the PGE application for solar.
                    I called/texted him after I noticed the problem and he fixed right away.)
                    A bit confuse. should I put EV-A or E-6 for electric car and solar?
                    Without electric car, PG&E website states I would need to pay over 20% more per year for EV-A over E-6. I am not sure if EV-A is worth it if I add electric car in the mix.

                    Comment


                    • #11
                      Originally posted by solar_newbie View Post
                      A bit confuse. should I put EV-A or E-6 for electric car and solar?
                      Without electric car, PG&E website states I would need to pay over 20% more per year for EV-A over E-6. I am not sure if EV-A is worth it if I add electric car in the mix.
                      There are lots of discussions on whether to use EV-A or E-6 for homes with Solar [U]AND [/U]EV
                      This is the thread I partially based my decision on. http://www.myrav4ev.com/forum/viewtopic.php?f=7&t=574

                      I came down to select EV-A because I found it easy to understand.
                      For EV-A, it's a simple Time of Use. So the solar generates at peak hour will earn me credit at the peak-rate. I will charge my EV at off-peak hour. In summer, the ratio between peak to off-peak rate is about 4:1. That means for each kWh solar generation at peak time, I earn credit enough for 4kWh EV charging.

                      I can't totally understand how the E-6 (Tiered TOU) plan work.
                      I can understand that if I use a lot more than my solar generates during each month, then I move up the tier and each unit of energy becomes more expensive (I need to pay or use my credit, all done during a ture-up year cycle)
                      What I don't understand if I over generates a lot during summer month (which will be very likely as every solar home rely on the over generation in summer to supplement the usage in winter), whether the rate for each over generation goes through tiered rate as well.
                      This gets complicated because it appears PGE calculate debit/credit for each month (even though you only ture-up once a 12 month period). So in summer, I could see a lot of energy that I generate but don't need.

                      To illustrate my question:

                      Tier 1 is 300kWh --> lowest rate for each TOU period
                      Tier 2 is 301kWh to 330kWh --> Middle rate for each TOU period
                      Tier 3 is 331kWh to 600kWh --> Most expensive rate for each TOU period


                      In winter months: because of the small amount of solar energy generated, I may not go up to higher tiers. But I will most likely use more than what I generate. In that case, I will be charged for the lowest rate for electricity used during each TOU period

                      In summer months, what if my system generates more than 330kWh AFTER covering what I use during the same month, will PGE give credit based on the tier 3 rate? (since I going beyond the tier on the opposite side).
                      To further complicate the matter, do PGE only give credit at high tier rate for the last a few days of each month during the summer after my over generation have pass the tier level?

                      I found my head spin thinking about all these. So I decided to try EV-A for a year. By then, PGE website will have historical data to simulate if switching to E-6 will be better.

                      Comment


                      • #12
                        Don't have EV so decide to switch to E6 from E1 even though I work from home and my main concern is hot summer day running AC

                        From my quick calculation, I should be able to make enough power in winter to offset day time/peak hour usage and for summer, I think for every 2 days not using AC, I will bank enough credit to run 1 full day of AC which means 10 days of AC on average per month which I don't think I will even come close to..

                        I figure since E6 will not be offered anymore after this year, I should try it out first and I can always switch back to E1 or the new TU next year

                        Comment


                        • #13
                          Originally posted by dshenmdyn View Post
                          There are lots of discussions on whether to use EV-A or E-6 for homes with Solar [U]AND [/U]EV
                          This is the thread I partially based my decision on. http://www.myrav4ev.com/forum/viewtopic.php?f=7&t=574

                          I came down to select EV-A because I found it easy to understand.
                          For EV-A, it's a simple Time of Use. So the solar generates at peak hour will earn me credit at the peak-rate. I will charge my EV at off-peak hour. In summer, the ratio between peak to off-peak rate is about 4:1. That means for each kWh solar generation at peak time, I earn credit enough for 4kWh EV charging.

                          I can't totally understand how the E-6 (Tiered TOU) plan work.
                          I can understand that if I use a lot more than my solar generates during each month, then I move up the tier and each unit of energy becomes more expensive (I need to pay or use my credit, all done during a ture-up year cycle)
                          What I don't understand if I over generates a lot during summer month (which will be very likely as every solar home rely on the over generation in summer to supplement the usage in winter), whether the rate for each over generation goes through tiered rate as well.
                          This gets complicated because it appears PGE calculate debit/credit for each month (even though you only ture-up once a 12 month period). So in summer, I could see a lot of energy that I generate but don't need.

                          To illustrate my question:

                          Tier 1 is 300kWh --> lowest rate for each TOU period
                          Tier 2 is 301kWh to 330kWh --> Middle rate for each TOU period
                          Tier 3 is 331kWh to 600kWh --> Most expensive rate for each TOU period


                          In winter months: because of the small amount of solar energy generated, I may not go up to higher tiers. But I will most likely use more than what I generate. In that case, I will be charged for the lowest rate for electricity used during each TOU period

                          In summer months, what if my system generates more than 330kWh AFTER covering what I use during the same month, will PGE give credit based on the tier 3 rate? (since I going beyond the tier on the opposite side).
                          To further complicate the matter, do PGE only give credit at high tier rate for the last a few days of each month during the summer after my over generation have pass the tier level?

                          I found my head spin thinking about all these. So I decided to try EV-A for a year. By then, PGE website will have historical data to simulate if switching to E-6 will be better.
                          I have the same head ache, BUT E-6 is gone by this Dec So I am thinking to try E-6 first ... as you do not have chance to do the change later.

                          Comment


                          • #14
                            Originally posted by solar_newbie View Post
                            I have the same head ache, BUT E-6 is gone by this Dec So I am thinking to try E-6 first ... as you do not have chance to do the change later.
                            Didn't realize that until just now. Well, I will just use EV-A and get the satisfaction every time I see power being returned to PGE during peak hour for credit.

                            Comment


                            • #15
                              Originally posted by solar_newbie View Post
                              I have the same head ache, BUT E-6 is gone by this Dec So I am thinking to try E-6 first ... as you do not have chance to do the change later.
                              E-6 is gone, but will be replaced with another tiered TOU plan, so the problem will still exist.

                              The answer to your (and dshenmdyn's) question is in this document: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_NEM.pdf

                              It still requires interpretation, and I'm not sure I completely understand the nuances, but the content starting on Sheet 8 of the document describes your case.

                              Section 2.b covers TOU rates and says:
                              If the eligible customer-generator is a net consumer during any discrete TOU period, the net kWh consumed shall be billed in accordance with that same TOU period in the eligible customer-generator’s OAS.
                              If the eligible customer-generator is a net generator during any discrete TOU period, the net kWh produced shall be valued at the same price per kWh at the same TOU period in the eligible customer generator’s OAS.
                              In the event that at the end of the monthly billing cycle, an eligible customer generator’s
                              net usage for all TOU periods totals zero (i.e. net generation in one or more periods exactly offsets the net usage in all other periods), then
                              the value of usage and/or generation will be calculated using Tier 1 rates (as set forth in the OAS).
                              (OAS stands for "Originally Applicable rate Schedule" - i.e., the rate that would apply independent of net metering)

                              Basically the way that I read this text is that each TOU period (peak/part-peak/off-peak) is totalled up independently. So a typical day might look like:
                              Peak: Net generator 12 kWh
                              Part Peak: Net consumer 9 kWh
                              Off-Peak: Net consumer 5 kWh

                              Each period will be billed (or credited) according to the appropriate rates for the period.

                              Section 2(b) is not specific on how Tiers get calculated, so we have to look to section 2(a) for information on that (2(a) is titled (For an OAS with baseline rates) and says:
                              If the eligible customer-generator is a net consumer, the eligible customer generator will be billed in accordance with the eligible customer-generator’s OAS.

                              If the eligible customer-generator is a net generator, the net kWh generated shall be valued at the rate for the kWh up to the baseline quantity, with any excess kWh generated, valued at the rate for the appropriate tier level in which the equivalent kWh of usage would fall.
                              Basically what this is saying, by my interpretation, is that tiers apply both to net generators and net consumers.

                              Unfortunately, this still leaves some ambiguity.

                              The baseline rates for E-6 are determined on a daily basis - so it's total consumption for the day, independent of the time the consumption happened that would normally determine which tiers apply. The percentage of usage that comes from each tier would then be applied back to each period - so if 20% of total usage for the day was in Tier 2, 20% of your peak usage would be billed at Tier 2 rates, as would 20% of your part- and off-peak usages.

                              The question would be, if you're a net generator in some TOU periods, and a net consumer in others, how the Tiering is determined - is it determined by the magnitude of usage/generation in the individual period or over the whole day?

                              I would say the most consistent way of interpreting this (and thus the way I believe it will work), is that the Tier is determined by total net usage during the day. So in my example, total net usage was 3 kWh, which is Tier 1 for all geographies (The baseline numbers also vary by region, so geography is important for calculating rates under E-6).

                              If net usage had been high enough to put 20% of the usage in Tier 2, then the same rules as base E-6 would apply, except that it would apply to both net generation and net usage during the individual periods. So in my example, 20% of the net generation during peak hours would be credited at Tier 2 with the remaining 80% credited at Tier 1, etc.

                              The E-6 rate is described in this document, btw: http://www.pge.com/tariffs/tm2/pdf/ELEC_SCHEDS_E-6.pdf
                              Last edited by ulrich; 10-01-2015, 04:56 PM. Reason: corrections

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