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  • #31
    Originally posted by dust999 View Post
    Thank you for taking the time to post this comprehensive account of your decision process. Although I'm on the east coast it has some great info which will guide some of my decisions. Currently choosing between the LG300N1K-G4 and the Sunpower x21-335, both with a SMA string inverter. My quotes for the LG are way higher than yours, the best I have at the moment is $3.98. The SP panels are at $4.50.
    I have SP E20s (44) in Maryland. My installer told me X21s were overpriced and recommended avoiding until the price came down. I'd be glad to share my experience in PM.

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    • #32
      Originally posted by jakepv View Post
      Here was my journey through the solar acquisition process with the caveat that I am certainly not an expert in any form or fashion. I'm simply sharing my experience for the benefit of the community...
      Great summary - only thing I didn't see was fireproof paint on panel where the inverters were mounted... and any DC surge protection needed?

      14.388 kW: 44 Sunpower E20 327 with SMA SB 5000 (2) & SB 3000 with DEHN 900-930 DC Surge Protection

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      • #33
        Can you PM me the installer name?

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        • #34
          Great information Jake!

          Originally posted by jakepv View Post
          Here was my journey through the solar acquisition process with the caveat that I am certainly not an expert in any form or fashion. I'm simply sharing my experience for the benefit of the community...

          - Entire process from day one to contract signing was one month
          - First calls were to three of the national companies. Solar City, Sunrun and Sungevity (which btw is partnered with Sunrun which i didn't know at first)
          - Since I decided to purchase versus lease, none of these companies really had me excited or wowed with their components or pricing.
          - I then developed a list of local companies to solicit bids.
          ----- This is a searchable database that shows all of the installers in your area with active projects, how many, purchase vs lease, and avg cost per watt. I focused on the installers that had a balance of low cost per watt and a high number of projects in my area.
          ----- www.sandiegouniontribune.com/bestof /2015/for-the-home/solar-panel-company/ I called the top five and three responded.
          ----- I scoured this forum and asked around for recommendations
          ----- Total # of bids = seven
          - Had face to face mtgs with five of the seven and was able to immediately cross off two (poor preparation, unprofessional presentation, etc.)
          - After reviewing bids, was able to quickly eliminate two more due to their "pushing" of specific brands, unresponsiveness, and general take it or leave it attitude
          - With the three remaining companies i began the negotiations process and essentially created a competitive bidding situation. After all of my research and due diligence i was ultimately comfortable with any one of the three and was now able to focus on cost
          - The bidding war eliminated one more company so I was down to two
          - The final two bids were essentially the same design, specs, and warranties. Neither would come down in price any more. What broke the tie was I asked for the Solar Edge 25 yr extended inverter warranty to be included at no additional cost. This retails for approx. $500. http://www.solaredge.us/groups/us/service/warranty
          - Contract signed.

          Panels
          - I decided on LG after having considered SolarWorld and SunPower. I couldn't personally justify the premium cost for SunPower and I felt that LG offered more stability from a going concern perspective compared to SolarWorld.
          - I studied up on understanding the differences in panel models. The only significant difference in my mind is that the B3 models have a 10yr warranty while the newer G4's are 12 yrs. The 300 panels I ended up going with are all black but this didn't have any impact on my choice of installers.

          Inverter
          - SolarEdge was the choice here based on what I read on this forum
          - You can download the SE design tool program and run your system through it to ensure that the installers aren't overselling you anything http://www.solaredge.us/groups/us/in.../site-designer In my case, I was initially designed for the 6000 inverter and 300 optimizers. By playing with the design tool, I found that a 5000/320 combination would provide slightly more output today and also allow a little more room and flexibility for future growth if necessary.

          Mounting and Racking
          - This is the one area that I struggled the most with and there isn't a ton of information out there.
          - There are a number of "systems" eg Quickmount, ProSolar/Tiletrac, Unirac, Ironridge, etc.
          - I ultimately wanted a mounting system that was double flashed since roof leakage was my number one concern
          - The installer I chose uses Ironridge

          Warranties
          - LG G4 panels are warrantied for 12 yrs (10 yrs for B3) parts and 25 yrs production. To this day, no one has clearly explained to me the difference between parts and production since in my simple mind if the panel is not producing, the parts aren't working. Some installers said LG will absolutely cover the panel and labor to replace it while others said no one really knows since LG panels aren't that old. So I let this one die on the vine and assume (correctly or incorrectly?) that after year 12, if there's a failure, LG will give me a new panel but I'll have to pay for the labor to swap it in.
          - SolarEdge warranties the optimizers for 25 yrs BUT some installers don't tell you that the inverter is only warrantied for 12 (very misleading in my opinion). SE offers an extended warranty to 20 or 25 years and you can buy that directly from SE. If you are the warranty type (like me) do not include this in the initial bidding process because it will likely be marked up. I used the extended warranty as a way to add more value to the deal once the installers would no longer lower their prices
          - Ironridge has a 20 year warranty
          - The installer I chose has an industry standard 10yr workmanship and roof penetration guarantee

          Financing
          - Obviously this depends on your situation but for me, I went with a HELOC. 3.98% for the first 12 months, then PRIME + 0 with a floor of 4.25%
          - Other options included:
          ----- HERO financing typically is around 8% and is rolled into your property taxes but there are a few different options to choose from
          ----- Installer financing is typically a 12 yr loan @ 2.99% with a balloon payment equal to the 30% tax credit due in 12 months. Also know that the principal cost is higher than a cash purchase as you're basically buying down the interest rate.
          ----- One installer offered essentially two loans, a one year same as cash (0.0%) loan on the 30% tax credit which is due in 12 months and the typical 12 yr 2.99% loan on the remaining 70%
          - None of the installers accepted credit cards for anything other than the deposit

          My suggestions:
          - Decide early on whether you are looking to buy or lease. If you are unsure, you will be navigating through muddy waters until you make this decision.
          - Do your homework, knowledge is power. The more you know, the quicker you'll identify who's trying to take advantage of you.
          - Ask lots of questions and track who answers/responds. I was shocked at how many companies did not respond to questions or didn't follow up
          - Beware of the companies that are urging you to "act now before time runs out"
          - Unless you have limited roof space, remember that a watt is a watt regardless of the panels wattage or who the manufacturer is. Lower wattage panels can be significantly less expensive. Read this bullet point again.
          - Some installers will tout "the highest efficiency" panels. All this means is that they are higher wattage panels so naturally they are more efficient. Read the previous bullet again
          - I found it extremely difficult to get apples to apples comparisons across the bids so do your best, it will be worth the effort. It's really the only way to get installers competing against each other. A company that is willing to invest time and work with you to earn your business is likely a good partner to have long term.
          - Check references and reviews. www.SolarReviews.com , BBB, etc. are your friends. Also check licenses at https://www2.cslb.ca.gov/OnlineServi...ckLicense.aspx A lower license number means they've been in business longer.
          - Another good source of information is to download the CSI data which can be filtered. A little geeky to be honest but a good way to validate an installer's history and also to see what other folks have used and paid. https://www.californiasolarstatistic...ata_downloads/
          - Validate bids' power outputs by using PVWatts http://pvwatts.nrel.gov/ or the SE Design Tool I referenced above
          - Be aware of and understand mechanics liens so ask the installer if subcontractors are used

          - Definitely take time to understand how net metering works http://www.cpuc.ca.gov/PUC/energy/Di...etmetering.htm
          - Also determine if time of use (TOU) may benefit you http://www.sdge.com/clean-energy/ev-rates
          - How much is solar worth? In addition to PVWatts, here's another model
          - Another study on the value of existing PV systems http://www.nytimes.com/2015/02/22/re...lues.html?_r=0
          - If possible, get at least two installers to compete for your business. I was able to get an installer's initial bid down by almost $1 per watt this way, which equated to almost $5k.

          In summary, I went into this thinking it would only take a week, two at most. One month later, I may have went a little overboard on my research and due diligence but I believe it eventually saved me $5k and gave me peace of mind.

          Thanks to everyone who helped me along the way and best of luck to all of you embarking on your own PV adventure!

          Mod Note, this is excellent work. However I did have to remove a couple of links that help our opposition while hurting our own site, please be mindful not to post links to the opposition, thankyou.
          I went through a similar journey and came to many of the same conclusions. In the end i was debating between installing LG myself (with help from electrician) and SP by contractor. It was a premium i was willing to pay and i chose SP. On the SE vs. Enphase debate, i came to the same conclusion and chose SE. The biggest issue for me there was reliability and I think there are less moving parts with the SE product. I'm curious, what racking system did you pick? I'm trying to choose between quickmount and snap n' rac.

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          • #35
            Originally posted by sdhomeowner View Post
            I'm curious, what racking system did you pick? I'm trying to choose between quickmount and snap n' rac.
            I had no say in the mounting and racking, the installer uses quickmount pv and ironridge.

            Comment


            • #36
              Originally posted by mcarney52 View Post
              I have SP E20s (44) in Maryland. My installer told me X21s were overpriced and recommended avoiding until the price came down. I'd be glad to share my experience in PM.
              Can you PM me? I am in Maryland as well and interested in your experience. Thanks.

              Comment


              • #37
                Contact info for your installer (PM me)

                Originally posted by jakepv View Post
                Finally decided on an installer!

                The quick summary:
                - 5.7 kW system
                - 19 LG 300N1K-G4 panels
                - SolarEdge 5000 inverter & P320 optimizers

                $3.37/W

                I'll share additional thoughts on the sales/buying process as well as progress going forward throughout the duration of my project.

                Thanks again to everyone who has helped me along the way. This forum has been extremely valuable and I've reaped the benefits economically and intellectually.
                I'm new to this thread, and thus cannot PM or email. I read all of your homework and threads, and am interested in the company with which you chose. Please PM me.

                Thanks in advance.

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                • #38
                  Great Success!

                  I am happy to report that as of 11/4/15 my system is up and running!

                  http://pvoutput.org/list.jsp?userid=45486

                  There were definitely some speed bumps along the way which I'll detail in a subsequent post. I'll also share some pics of the final install.

                  Thanks again to this forum, an invaluable resource and community!

                  Comment


                  • #39
                    Originally posted by jakepv View Post
                    I am happy to report that as of 11/4/15 my system is up and running!

                    http://pvoutput.org/list.jsp?userid=45486

                    There were definitely some speed bumps along the way which I'll detail in a subsequent post. I'll also share some pics of the final install.

                    Thanks again to this forum, an invaluable resource and community!
                    Hey Jake: Nicely done !

                    FWIW, measured GHI at my array on 11/06 was about as good as it gets in S.D. Co. this time of year for atmospheric clearness and lack of any cloud cover. 11/05 was pretty good but had some high cirrus clouds.

                    11/05 was a bit cooler allowing a slightly greater system output for what turned to be slightly less GHI on that day (~ 1% less) because of a few whispy clouds. Looking at your output vs. mine, I'd suggest yesterday might be a good indication of your system performance under clear skies this time of year. More FWIW, the TMY3 for Miramar shows two pretty clear days for 11/05 and 11/06. Therefore, hourly PVWatts output for your system for those days compared to measured/recorded might show some insight to how conservative PVWatts may be, and maybe an indication of whether or not changing the PVWatts system loss # or other advanced parameters for your system may lead to a better estimate of long term average annual system output. Just sayin'.

                    BTW: How sure are you of that 135 deg. azimuth ? Not doubting the output, but the PVOutput #'s seem high, even for a clean array compared to PVWatts, and my own modeling stuff for clear days. I haven't checked SAM yet, but my modeling stuff gets pretty close to SAM for TMY irradiance and the algorithm is about the same for my clear day modeling. I suppose if you reduce the system losses to zero and throw in about 5% or so to account for conservativeness in the panel output rating, that might account for it. Whatever it is, it is.

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                    • #40
                      Thanks JPM. Conceptually, it sounds like you're providing guidance on how I can benchmark my system against PVWatts for this time of year? I looked up GHI and I'm still fuzzy on how I can confidently use this info in an analysis...I have some homework

                      My layout actually has panels on two rooftops, 14 facing SE and the other 5 SW so azimuths are probably closer to 150* and 240*. Does this help clarify any of the output numbers you're seeing?

                      I'm happy to provide more info if you want to drill into validating your models, I'm always looking for opportunities to learn something new.

                      Comment


                      • #41
                        Originally posted by jakepv View Post
                        Thanks JPM. Conceptually, it sounds like you're providing guidance on how I can benchmark my system against PVWatts for this time of year? I looked up GHI and I'm still fuzzy on how I can confidently use this info in an analysis...I have some homework

                        My layout actually has panels on two rooftops, 14 facing SE and the other 5 SW so azimuths are probably closer to 150* and 240*. Does this help clarify any of the output numbers you're seeing?

                        I'm happy to provide more info if you want to drill into validating your models, I'm always looking for opportunities to learn something new.
                        You're welcome.

                        On quantifying: sort of. Using Miramar as the PVWatts station, those two days used TMY3 data from 11/05 and 11/06/2003. Those two days were pretty clear as modeled by TMY3. The Miramar temps. were a bit lower than actuals for 11/05 and 11/06/2015.

                        On the array azimuths, thanx. That clears it up some.

                        So, if you take the PVWatts output estimate for those days for each array orientation, treating each orientation as a separate array, and sum the output for both arrays, you'll have a "sort of" PVWatts estimate of a clear day's output for those days.

                        Now, knowing that, and knowing, or having an estimate of actual output for those days, and also knowing they were about as good as it gets this time of year, particularly 11/05, if you want to, you can go back into PVWatts and change the default rating parameters it uses in such a way that the PVWatts output will match what your stuff reported as actual output.

                        Again, a real SWAG, but if you do that, what you'll have is perhaps a slightly better PVWatts estimate (only) of long term output for your system, or anyone's in N.C. San Diego, than simply using the PVWatts default values.

                        I suspect if you do all of the above, what you'll wind up with is something that's more than likely a bit closer to the long term output estimate you'll get using SAM, or other estimating models, but without the time and hassle most folks encounter when they attempt to use SAM. That time and hassle is part of the homework.

                        I like this stuff, but most people are not so inclined as to get as involved as learning all the stuff SAM needs as background knowledge so as not to make mistakes in interpretation and come to poor decisions or perhaps dangerous or at least costly mistakes based on ignorance. What I'm suggesting is a sort of a shortcut.

                        Either or any way, all this is still about estimating output. Given all the inherent uncertainty, not only in the fuel source availability (the amount of irradiance and its variability), and the limitations in instrument accuracy, any long term estimates of future output are, at least around here, and no better than maybe +/- 5% or more, more so for shorter periods, and daily or weekly predictions a pipe dream.

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