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  • Choosing solar in the SF Bay Area.

    Hi Everyone,

    I live in the Bay Area in a house with no shade issues and a roof that will need different panel placements without all being on the south. I love the amount of information and expertise I'm taping into so far here. I've been collecting bids and so far I've got information, but I'm not seeing anything pre-tax rebate below $3.50 per watt. I've been using the solar-estimate website as well as a post on here for the San Jose company Green Power. Here's what I have so far. I'm also trying to take care of my sub-panel at this point to with Federal Pacific breakers as I'm understanding that this type of upgrade will still fall under the federal tax rebate. It's interesting that some companies give all the information up front and some seem to be more vague. Any thoughts or things I'm not doing right. Any suggestions would be appreciated.

    Thanks,
    Derrall

    Screen Shot 2017-07-10 at 10.06.53 PM.png


  • #2
    Looks to me like you're either got the PetersenDean price/Watt or total price before subpanel cost typo'd (total before subpanel = $24,346 maybe ?).

    Forget Sunpower - good stuff, but overpriced for what you get and therefore not nearly as cost effective.

    As for price, w/4 different orientations and not a super large system, $3.50/Watt may be about as good as you're likely to get.

    If you shared prices with vendors, as the narrow spread of the non Sunpower pricing may indicate, that's another big reason of what are probably several why you're not seeing, and probably won't see if you continue that practice, much spread in prices. Reason: Although $3.50/STC Watt may not be a bad price, sharing prices with vendors is a very poor negotiating tactic. It gives the vendors an essential piece of information and what they're looking for - the exact price they need to be under to get your business. Then, in theory (and usually close to practice) they only need to go $0.01 lower. Going lower than that any they're leaving $$ on the table. Share prices if you want, but one thing I learned after making a good living for 10 years as a peddler in a prior iteration of life is that it's a bad move if the goal is to get the sharpest price. Besides, there's no gain for the buyer (you). Think about it from their perspective, not yours.

    Before you go further I'd suggest you consider doing two things:

    1.) Download and read" "Solar Power Your Home for Dummies", a free net download, or ~ $25 for an updated hard copy in bookstores or Amazon. Knowledge is power. Get some.
    2.) Download PVWatts from NREL, a user friendly sizing/estimating model. Read all the help/info screens a couple of times, get your array's orientations right, use a 10 % system loss parameter instead of the 14 % default and do some runs. It's a quick learning curve. Do each of the 4 orientations separately and combine the results.

    Seems like the annual output estimates clump into two groups, of ~ 1,400 kWh/yr. per STC kW and ~ 1,700 kWh/yr per STC kW. Maybe Some vendors are not including shading or some other factor(s). Whatever the reasons, the estimates ought to be reasonably close to one another, at least less than the 20 % difference you're showing. Doing your own output estimates may give you some additional insight as to where the estimated output #'s are coming from. W/ 4 different orientations I'd put more trust in the 1,400 kWh/yr. #. 1,700 kWh/yr. is what you might expect for a south facing array in a sunnier climate. That's not what you have.

    Be deliberate and don't do anything until you educate yourself. Come back here and ask questions to fill in any knowledge blanks you generate.

    Welcome to the neighborhood and the forum of few(er) illusions.

    Comment


    • #3
      Thank you for your valuable information. I'm certainly taking it to heart and need to step up my evaluations compared to other home upgrades.

      Originally posted by J.P.M. View Post
      Looks to me like you're either got the PetersenDean price/Watt or total price before subpanel cost typo'd (total before subpanel = $24,346 maybe ?).
      Yes, I wrote down the pre-discounted price it should have been $21,916


      Forget Sunpower - good stuff, but overpriced for what you get and therefore not nearly as cost effective.
      Seems to be the consensus here, the company quoted me the Panasonic system and touted the warranty as being better now than Sunpower. So I guess they are playing off the more expensive panels expecting me to go with the cheaper Panasonic system. Everyone else has been talking Enphase micro-inverters and this is the first one bringing up string inverters. I just assumed with my simple electronics knowledge that a parallel system with monitoring and dealing with a panel having problems would make more sense then something in series, but I see it's more complex than that with individual panels in the string system I was shown still being capable of being monitored individually.

      As for price, w/4 different orientations and not a super large system, $3.50/Watt may be about as good as you're likely to get.
      Good to know as I'll at least not feel badly if that is to be expected.

      If you shared prices with vendors, as the narrow spread of the non Sunpower pricing may indicate, that's another big reason of what are probably several why you're not seeing, and probably won't see if you continue that practice, much spread in prices. Reason: Although $3.50/STC Watt may not be a bad price, sharing prices with vendors is a very poor negotiating tactic. It gives the vendors an essential piece of information and what they're looking for - the exact price they need to be under to get your business. Then, in theory (and usually close to practice) they only need to go $0.01 lower. Going lower than that any they're leaving $$ on the table. Share prices if you want, but one thing I learned after making a good living for 10 years as a peddler in a prior iteration of life is that it's a bad move if the goal is to get the sharpest price. Besides, there's no gain for the buyer (you). Think about it from their perspective, not yours.
      I shared a ceiling of aprox. $20,000 with two vendors and then realized that I wanted to see how they came in and just gave them the PG&E usage data and nothing else.

      Before you go further I'd suggest you consider doing two things:

      1.) Download and read" "Solar Power Your Home for Dummies", a free net download, or ~ $25 for an updated hard copy in bookstores or Amazon. Knowledge is power. Get some.
      Just ordered the Kindle version for $12, just not comfortable with downloading something that was not intended as free.

      2.) Download PVWatts from NREL, a user friendly sizing/estimating model. Read all the help/info screens a couple of times, get your array's orientations right, use a 10 % system loss parameter instead of the 14 % default and do some runs. It's a quick learning curve. Do each of the 4 orientations separately and combine the results.
      I feel dumb about my approach with the tool. I followed the recommendation to use this a few days ago, and got frustrated trying to include the different roof placements and gave up, not thinking to just do four different assessments, duh.

      Seems like the annual output estimates clump into two groups, of ~ 1,400 kWh/yr. per STC kW and ~ 1,700 kWh/yr per STC kW. Maybe Some vendors are not including shading or some other factor(s). Whatever the reasons, the estimates ought to be reasonably close to one another, at least less than the 20 % difference you're showing. Doing your own output estimates may give you some additional insight as to where the estimated output #'s are coming from. W/ 4 different orientations I'd put more trust in the 1,400 kWh/yr. #. 1,700 kWh/yr. is what you might expect for a south facing array in a sunnier climate. That's not what you have.
      This is a great point and reason for me to independently work out the numbers rather than relying on someone else. I think I was allowing the companies to dictate these things because in my mind I was choosing well rated and respected companies and assuming they'd be doing me right.

      Be deliberate and don't do anything until you educate yourself. Come back here and ask questions to fill in any knowledge blanks you generate.
      Will do! I get the idea and it's just the same as what I try and get my students to do, think for yourself and make sure to understand all the elements before starting to do a project.

      Welcome to the neighborhood and the forum of few(er) illusions.
      Thanks again for the warm welcome and making me feel a part of this community!

      Comment


      • #4
        Originally posted by derrallg View Post
        Thank you for your valuable information. I'm certainly taking it to heart and need to step up my evaluations compared to other home upgrades.



        Thanks again for the warm welcome and making me feel a part of this community!
        You are most welcome. If you like our service, tell your friends.

        In the meantime, question everything everyone says or tells you until you understand what's being communicated. There's a lot of B.S. out there.

        Comment


        • #5
          Welcome @derrallg!

          Looks like you're off to a great start! The Panasonic/SolarEdge offering looks great -- but I'm biased as I have one myself (37 330W Panasonic panels w/37 SE P400 Optimizers and an SE 11.4kW Inverter). Such a system is generally not referred to as a "string inverter" but rather a "DC Optimizer" solution. Classic string inverter systems do not have DC Optimizers (separate MPPT controller and DC voltage buck/boost transformer for each panel).

          The per panel optimizers give the SolarEdge solution all of the same bells and whistles (which I just love) as an Enphase microinverter solution. The benefit is that the SE cost per Watt is usually slightly less than Enphase, and the longevity (equipment and company) of SE is likely much better than Enphase who has been on their last leg, financially, now for at least two years. But both are youngish companies so only time will tell.

          I, too, was hoping to get closer to $3.00/Watt pre-tax rebate, but in the end, it was more like $3.21/Watt for my system on the East coast. Of course, by the time I added a new roof it was way too expensive (-: If you're looking to try for a lower cost per watt, I would get the following quotes:

          1) Identical Panasonic / SE solution from a second vendor -- be sure both vendors are of good quality and very highly rated

          2) Similar Solar Edge solution, but with less expensive panels. For example Canadian Solar, Hanwha Q-Cells, Trina, or LG Neon2 (only slightly less than Panasonic). Depending on the panel, and your installer's volume for than brand, you might be able to drop your per watt cost by ~20-40 cents. BUT, keep in mind none of these panels have as good of a warranty (defect and productivity) nor as good of a thermal performance coefficient as the Panasonics do. That said, all four brands are still very good. BUT, the efficiency of all of these panels is lower so you'll need a few more panels (if they fit on your roof) to get the same DC kW sized array.

          Be sure you buy with Cash or get good terms on a loan. Don't do a lease or PPA or you may/will have trouble selling the home in the future (and you're ROI won't be as good).

          Based on your usage, and any incentives (Federal tax, tiered rate plan?, other state or power company incentives?) do you have a feel for your time to break even in years? Do you expect to still be living there by then? How old is your current roof? Will it last 20-40 yrs?

          Best of luck!
          Jonathan

          Comment


          • #6
            Thank you for your input Jonathan!

            Originally posted by JSchnee21 View Post
            Welcome @derrallg!

            Looks like you're off to a great start! The Panasonic/SolarEdge offering looks great -- but I'm biased as I have one myself (37 330W Panasonic panels w/37 SE P400 Optimizers and an SE 11.4kW Inverter). Such a system is generally not referred to as a "string inverter" but rather a "DC Optimizer" solution. Classic string inverter systems do not have DC Optimizers (separate MPPT controller and DC voltage buck/boost transformer for each panel).
            Yes, the package looked good from my perspective too. I'm learning more about this type of "DC Optimizer." He showed me the box that has individual plugs for each panel.

            The per panel optimizers give the SolarEdge solution all of the same bells and whistles (which I just love) as an Enphase microinverter solution. The benefit is that the SE cost per Watt is usually slightly less than Enphase, and the longevity (equipment and company) of SE is likely much better than Enphase who has been on their last leg, financially, now for at least two years. But both are youngish companies so only time will tell.
            I'm glad to see someone was packaging something other then Enphase. It was strange that they seem to be the most offered and yet I've been reading about a fair amount of folks recommending the SolarEdge converters.

            I, too, was hoping to get closer to $3.00/Watt pre-tax rebate, but in the end, it was more like $3.21/Watt for my system on the East coast. Of course, by the time I added a new roof it was way too expensive (-: If you're looking to try for a lower cost per watt, I would get the following quotes:
            We did our roof two years ago and then have been saving up to do solar now. I agree it would have been expensive to try and do both at the same time. I think I'll be happy if I can get it down to $3.20/Watt.

            1) Identical Panasonic / SE solution from a second vendor -- be sure both vendors are of good quality and very highly rated
            That's a good idea, I was wondering how to approach going back to some vendors to see what I can shift to my advantage and SkyPower has offered to price match anyone coming back with an offer for the same equipment.

            2) Similar Solar Edge solution, but with less expensive panels. For example Canadian Solar, Hanwha Q-Cells, Trina, or LG Neon2 (only slightly less than Panasonic). Depending on the panel, and your installer's volume for than brand, you might be able to drop your per watt cost by ~20-40 cents. BUT, keep in mind none of these panels have as good of a warranty (defect and productivity) nor as good of a thermal performance coefficient as the Panasonics do. That said, all four brands are still very good. BUT, the efficiency of all of these panels is lower so you'll need a few more panels (if they fit on your roof) to get the same DC kW sized array.
            Yeah I really like the Panasonic warranty/guarantee, their promise of a high power output after a the most amount of time. With my roof I can certainly fit more panels, but it might not be the best orientation.

            Be sure you buy with Cash or get good terms on a loan. Don't do a lease or PPA or you may/will have trouble selling the home in the future (and you're ROI won't be as good).
            We are definitely doing cash as I'm all about the ROI and the federal tax rebate.

            Based on your usage, and any incentives (Federal tax, tiered rate plan?, other state or power company incentives?) do you have a feel for your time to break even in years? Do you expect to still be living there by then? How old is your current roof? Will it last 20-40 yrs?
            These are all factors that have made this project much different than other home improvement projects. Unfortunately the California state rebates are long gone along with the PoCo ones. I'm figuring we'll be in this house till my youngest graduates from high school in about 13 years and I'll be retiring. The ROI I'm sticking to is about 6 to 7 years, so we should have 6 or 7 years where the system is payed for and I've got the reduced bills. Later when we sell the house there should still be quite a bit of efficient energy production left in the system.

            Best of luck!
            Jonathan
            Thank you again for your thoughtful response and questions.

            Comment


            • #7

              I suggest you also consider your PG&E rate plan in sizing your system. If you are on a TOU plan then I think targeting 90% of usage could lead to a lot of wasted NEM credit at true up. I used Green Power and I think they are good. If you want, you can ask them to give quotes for your preferred panel and inverter brands. I would stay away from Petersen Dean. I am not familiar with the other installers you listed.

              Comment


              • #8
                derrallg want to compare notes ? we're getting bids from the same vendors... I couldn't find a way to send private messages. I posted to your Google + account... I hope I'm not infringing TermsOfUse by asking for a side conversation with another board member,
                Last edited by JRqwertyui; 07-13-2017, 08:01 PM.

                Comment


                • #9
                  Originally posted by solardreamer View Post
                  I suggest you also consider your PG&E rate plan in sizing your system. If you are on a TOU plan then I think targeting 90% of usage could lead to a lot of wasted NEM credit at true up. I used Green Power and I think they are good. If you want, you can ask them to give quotes for your preferred panel and inverter brands. I would stay away from Petersen Dean. I am not familiar with the other installers you listed.
                  Yeah targeting 90% of annual usage is lkely too high a target for someone who doesnt use a lot during working hours, like running the AC from noon to 6. I assume you dont in sf. OTH if there is any chance you will be increasing usage signifiantly down the road, the next few years are the time to help payoff the system, so Id weigh future proof sizing vs. chance of you moving. PGE has already stated (subject to worsening) what their tou will be the immediate future, how they are changing the peak windows and shrinking the summer period down to 4 months. I would bet money the best case scenario, absolute best, is the future will only hold solar PV payoff periods near what they are today. What wont change however is doing those cost effective energy efficiency upgrades for your area.

                  Comment


                  • #10
                    Originally posted by JRqwertyui View Post
                    derrallg want to compare notes ? we're getting bids from the same vendors... I couldn't find a way to send private messages. I posted to your Google + account... I hope I'm not infringing TOU by asking for a side conversation with another board member,
                    There no PM feature on this forum.

                    Try the CSI data base. Look for the "NEM interconnection applications data set". It's only current through 04/30/2017, but has a lot of stuff you may find interesting. Be warned that here is a treasure trove of info in there, but it's not for the faint of heart. Note that a lot of people overpay. My guess is there would be a lot fewer such folks if they new about this database. There's lots of interesting tidbits in there.

                    Comment


                    • #11
                      Originally posted by solardreamer View Post
                      I suggest you also consider your PG&E rate plan in sizing your system. If you are on a TOU plan then I think targeting 90% of usage could lead to a lot of wasted NEM credit at true up. I used Green Power and I think they are good. If you want, you can ask them to give quotes for your preferred panel and inverter brands. I would stay away from Petersen Dean. I am not familiar with the other installers you listed.
                      I'm meeting with Green Power on Monday for a more detailed quote. Since we are on the TOU plan we try and use our appliances off peak and my Chevy Volt is set to begin charging so that it finishes at 6 AM. I'll look more in depth at the 90% target hadn't thought about being too high.

                      Comment


                      • #12
                        Originally posted by cebury View Post

                        Yeah targeting 90% of annual usage is lkely too high a target for someone who doesnt use a lot during working hours, like running the AC from noon to 6. I assume you dont in sf. OTH if there is any chance you will be increasing usage signifiantly down the road, the next few years are the time to help payoff the system, so Id weigh future proof sizing vs. chance of you moving. PGE has already stated (subject to worsening) what their tou will be the immediate future, how they are changing the peak windows and shrinking the summer period down to 4 months. I would bet money the best case scenario, absolute best, is the future will only hold solar PV payoff periods near what they are today. What wont change however is doing those cost effective energy efficiency upgrades for your area.
                        It's true, we don't use a lot during working hours. We live about 27 miles from SF, but we get the cooling effect of being close to the bay and don't need AC. When I looked at our times of heaviest usage it was during meal times. My wife sets the dishwasher and washer on time delays for the late evening and my car is charging late in the evening to be ready by 6 AM. I switched out all our lights to CFLs when we moved and am swapping out LEDs as they die. I can't imagine needing to plan for much increasing usage in the future.

                        Comment


                        • #13
                          Originally posted by JRqwertyui View Post
                          derrallg want to compare notes ? we're getting bids from the same vendors... I couldn't find a way to send private messages. I posted to your Google + account... I hope I'm not infringing TermsOfUse by asking for a side conversation with another board member,
                          I sent you a DM on Twitter with my email.

                          Comment


                          • #14
                            Originally posted by J.P.M. View Post

                            There no PM feature on this forum.

                            Try the CSI data base. Look for the "NEM interconnection applications data set". It's only current through 04/30/2017, but has a lot of stuff you may find interesting. Be warned that here is a treasure trove of info in there, but it's not for the faint of heart. Note that a lot of people overpay. My guess is there would be a lot fewer such folks if they new about this database. There's lots of interesting tidbits in there.
                            Yes, there is some interesting information here. If I understand this correctly, for residential average system cost in 2017 for a less than 10kW system in CA it was $4.67 per watt. Changing the data view to PG&E didn't make a difference for this statistic.
                            Screen Shot 2017-07-14 at 5.56.26 PM.png


                            Comment


                            • #15
                              It might go without saying, but make sure you filter out the obviously bad data, and use the DC rating, not AC. I've found that parsing the column with the module model to get the power and multiplying but the panel count works reasonably well.
                              CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

                              Comment

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