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  • popeyerg
    Junior Member
    • Aug 2021
    • 6

    #1

    Tesla Solar Panels...need some help

    Hi Everyone. I wanted to get some input on my Tesla order I have done.
    1st: The deal I am on right now is for the 16.32kW system. It is coming out to be 49 panels. This is representing my monthly avg bill to be $250/month. I am currently on Time of Use plan, which charges me less money during off peak time, and more during on peak time, during summer months. During the off season months I pay a lot less, but it seems to average out to be the same per month if I was on the regular plan. The Est Yearly Production for my system is showing to be 24,673kWh. Below is electricity use for the past 12 months according to my bill:
    KWH
    1025
    909
    901
    1596
    2580
    3519
    4983
    4074
    2956
    1973
    1107
    1399
    TOTAL 27022
    Based on the numbers above, I would assume the 16.32kW System from Tesla is the correct size to be installed for my house, right?

    2nd: The Assessment of my roof came back that my shingles were being rated at a 5.9PSF and Tesla requirements are 6.5PSF to do the install. Attached is a screen shot of what they are asking me to get done from a roofing company before the install:

    whats needed.JPG
    I have ran this by numerous roofing companies, and all of them have NO idea why Tesla would be wanting this work done prior to the install. Including the companies on their own vendors page for roofers in my area. The shingles on my roof are concrete tiles, 9-10lbs i was told. These shingles should have no problem being rates at 6.5 or higher. 1 roofing company said they are not interested in doing the job because they don't believe the work is required, and they didn't want to buy a bad job, and he walked off.

    Does any of this make any sense? I am trying to get answers but it seems that there are none on this matter, at least none that can I find.
  • J.P.M.
    Solar Fanatic
    • Aug 2013
    • 15015

    #2
    My condolences on your choice of Tesla. s

    Comment

    • popeyerg
      Junior Member
      • Aug 2021
      • 6

      #3
      Originally posted by J.P.M.
      My condolences on your choice of Tesla. s
      lol. well i went with the better price. i can still cancel it since it is not installed yet. that is why i need the input on #2.

      What other company would you use for the solar? I was quoted around $90,000 for a system to be installed by 2 companies already, seemed astronomical in price.

      Comment

      • J.P.M.
        Solar Fanatic
        • Aug 2013
        • 15015

        #4
        Originally posted by popeyerg

        lol. well i went with the better price. i can still cancel it since it is not installed yet. that is why i need the input on #2.

        What other company would you use for the solar? I was quoted around $90,000 for a system to be installed by 2 companies already, seemed astronomical in price.
        Since you ask, if I had a choice between Tesla and nothing, I'd take nothing and come out ahead.

        I'd have done a lot more research on my electrical use, prices, done a cost analysis, and done all I could to reduce electrical usage. Before all that I'd read "Solar Power Your Home for Dummies" before I got quotes and made an informed choice.
        You need an energy audit and use reduction more than you need to be throwing PV at a high electric use.

        After my experiences with PV vendors over the last 15+ years as the guy in my HOA who reviews/recommends to the HOA and then monitors all PV system installs and install progress, with a lot of that dealing with SolarCity and it's offspring Tesla, I wouldn't let them on my property.

        As for better price, buy cheap, buy twice.

        Take what you want of the above. Scrap the rest.

        Comment

        • oregon_phil
          Solar Fanatic
          • Jan 2019
          • 497

          #5
          popeyerg , I am making some assumptions about your quote with Tesla.

          1) You do not have the as built drawings for your home. The roofing system psf rating is itemized on the drawings.
          2) Tesla took some measurements on your home rafter system, underlayment, roofing system, local codes and came up with 5.9psf rating.

          In my jurisdiction, I was required to get a PE stamp on roof sistering changes made to my pole barn rafters. I suspect you will be required to do the same.

          Rooftop solar panel systems are much different than concrete roof tiles.

          Concrete roof tiles distributes the weight much more evenly onto your underlayment and rafter system.

          A solar panel system takes the entire weight of that system and directs that weight into point loads. Each and every point load must be able to support the system within shear and deflection guidelines. If you live in a snowy area, all that snow load gets redirected to solar panel roof attachment points instead of the roof itself.

          Now, Tesla is suggesting you remove the weight of the concrete tiles on your roof (which is probably several thousand pounds, you can calculate it) and replace it with asphalt shingles (which weighs alot less) so you can get your roof weight inside design limits. I think you would need a structural engineer to tell you for sure if this will work or what would work for your home.

          Comment

          • hajalie24
            Junior Member
            • Aug 2021
            • 4

            #6
            I tried going with Tesla, my god were they terrible. They went weeks without contacting me, when I finally got on the phone with them (after an hour+ on hold) they were like "umm... we had to cancel your project because your roof is incompatible (t-lock shingles)" No one bothered to tell me! Their website still said everything was in order. When I asked them how they knew my roof was incompatible, they said "satellite data." When I looked up what t-lock shingles are, I knew I didn't have them and sent them a pic stating my roof was updated in the last 5 years... never heard back from them. A company like that that treats their potential customers like that.. imagine how their support would be once you actually give them money. I'm glad it didn't work out.

            Also, after learning more about solar it's obvious Tesla's systems are really inefficient. They placed panels all over the place (west, south, and east facing) and they use string inverters. With string inverters, if one panel is shaded it bottlenecks the whole system and your whole system output goes down. So even if Tesla may be better $$/kW the output might not be as great going with a different system with less panels.

            Comment

            • J.P.M.
              Solar Fanatic
              • Aug 2013
              • 15015

              #7
              Originally posted by oregon_phil
              popeyerg , I am making some assumptions about your quote with Tesla.

              1) You do not have the as built drawings for your home. The roofing system psf rating is itemized on the drawings.
              2) Tesla took some measurements on your home rafter system, underlayment, roofing system, local codes and came up with 5.9psf rating.

              In my jurisdiction, I was required to get a PE stamp on roof sistering changes made to my pole barn rafters. I suspect you will be required to do the same.

              Rooftop solar panel systems are much different than concrete roof tiles.

              Concrete roof tiles distributes the weight much more evenly onto your underlayment and rafter system.

              A solar panel system takes the entire weight of that system and directs that weight into point loads. Each and every point load must be able to support the system within shear and deflection guidelines. If you live in a snowy area, all that snow load gets redirected to solar panel roof attachment points instead of the roof itself.

              Now, Tesla is suggesting you remove the weight of the concrete tiles on your roof (which is probably several thousand pounds, you can calculate it) and replace it with asphalt shingles (which weighs alot less) so you can get your roof weight inside design limits. I think you would need a structural engineer to tell you for sure if this will work or what would work for your home.
              All that has nothing to do with array or panel weight. It has everything to do with Tesla's B.S. methods as anyone with an eye and a balloon knot who knows anything about structural engineering and construction methods (including, apparently, several roofers per the OP) will attest.

              All tesla is proposing is to have the OP replace the tiles under the proposed array with composite shingles. They're doing so for their own
              (Tesla's) purposes. The reasons have nothing to do with weights.

              Any roof built to any type of building code in the developed world will have no problem handling the additional dead weight of any PV array currently available. Commonly, a residential roof is designed to handle a 40 - 50 lbm/ft^2 dead load plus a 20 lbm/ft^2 live load, and uplift and wind /seismic loads per local conditions all in various combinations. All weights are transferred to the roof trusses and that's where the point loads from array supports are taken out. the bottom line ois the dead weight (force) distribution winds up about the same. Panels and racking might add 4-5 lbm/ft^2 to the dead load. So, the weight of the array is not a major consideration. The uplift from wind on the array might be a consideration, but removing tiles will only add to the net wind uplift and so, IMO, ought not be done for that reason alone. But that's a minor reason.
              Any wind uplift needs consideration, but any downward wind force is already present without an array, although the force distribution on the roof by wind transferred to the roof through the supports will need checking. That's why the Good Lord made structural engineers.

              But all that has nothing to do with the real reason for the tile removal/replacement demand. The real reason is because it's cheaper for the vendor. SolarCity (and several other "Larry with a Ladder" type installers) tried several times to pull that B.S. on homeowners in my HOA that were dumb enough to use SolarCity.
              The reason why they want to do that is for their (the vendor's ) own benefit. It saves them money and time. Walking on tiles without breaking them takes time and is pretty much an exercise in futility anyway. Replacing broken tiles is costly and difficult (the replacements never match snd look like crap). Also, perhaps (that is, I don't know) Tesla's new (read cheaper) racking doesn't work well with tile roofs.

              Here's the kicker: The whole idea of replacing concrete tiles with composite shingles under an array is a bad one. It creates low areas at the tile to composition boundary/interface and creates discontinuities in the roof surface that are prime places where seams can and will open up and leaks will start. Vendors make moey putting product on roofs, not looking out for the long term interests of their marks.

              My HOA specifically disallows such methods. It's a method that will result in a way to increase the probability of getting built in leaks in a roof in places that can be very difficult to find much less get at and fix.

              Don't do it or don't allow it. You will regret it.
              Last edited by J.P.M.; 08-17-2021, 12:03 AM.

              Comment

              • oregon_phil
                Solar Fanatic
                • Jan 2019
                • 497

                #8
                You obviously have more experience with roofing and Tesla than I do so I stand corrected. I know Tesla doesn't get many recommendations on this site and now I know why.

                Comment

                • popeyerg
                  Junior Member
                  • Aug 2021
                  • 6

                  #9
                  Originally posted by J.P.M.

                  ...
                  What company do you recommend I get a quote from to get Solar installed? I am located in Las Vegas NV

                  Comment

                  • J.P.M.
                    Solar Fanatic
                    • Aug 2013
                    • 15015

                    #10
                    Originally posted by popeyerg

                    What company do you recommend I get a quote from to get Solar installed? I am located in Las Vegas NV
                    Well, first off, at your low electricity rates, like $0.11/kWh or so, and the rather low NEM reimbursement rates of 0.75 of the retail rate, that even after a serious energy audit and conservation measures, I'd wonder if PV can be anything like a cost effective option for your application.
                    If you're doing it to save money, I'm scratching my head at any logic that will get me to cost effectiveness with those parameters.

                    I'm unfamiliar with the Las Vegas PV market so I'm of no help as to recommendations on specific vendors.

                    But, as to your question about installers, I'd tap the brakes and rethink the whole PV thing.

                    However since you ask, and only FWIW, my opinion and usual advice is to:

                    1.) Avoid the big national firms, starting with Tesla. They're bottom feeders.
                    2.) Search out companies that are established, licensed, local electrical contractors that have been in business for at least 10 years or longer and have sold/installed PV for at least 5 of the last 10 years. Reason: They have survived in business and probably know what it takes to turn a profit, have other lines besides PV to continue in business, meaning they will probably be around after the solar boom is done, and are probably do quality, professional work. And, around here at least, since PV seems to be a cutthroat business, their prices are usually in line with the less professional outfits meaning a greater probability of more bang for your buck.
                    3.) get at least 3 quotes from qualified vendors.
                    4.) Negotiate tough but fair.
                    5.) NEVER share prices with competing vendors. You will only pay more. Think like a vendor. If you bite on the price matching con, you'll never pay one dollar less than the price you reveal. Sharp vendors know where the competition is pricewise anyway. You have no benefit in revealing any prices.

                    None of my $$, life or concern but if were you, or maybe if you knew some of what I think I might know, I'd examine my goals and if lowering an electric bill is high of that list of goals, I'd do a lot more homework on the most cost effective ways to achieve those goals, starting with an energy audit and use reduction before I looked into whether or not PV makes any sense for your application.

                    Take what you want of the above, scrap the rest.

                    Comment

                    • SunEagle
                      Super Moderator
                      • Oct 2012
                      • 15161

                      #11
                      Originally posted by J.P.M.

                      Well, first off, at your low electricity rates, like $0.11/kWh or so, and the rather low NEM reimbursement rates of 0.75 of the retail rate, that even after a serious energy audit and conservation measures, I'd wonder if PV can be anything like a cost effective option for your application.
                      If you're doing it to save money, I'm scratching my head at any logic that will get me to cost effectiveness with those parameters.

                      I'm unfamiliar with the Las Vegas PV market so I'm of no help as to recommendations on specific vendors.

                      But, as to your question about installers, I'd tap the brakes and rethink the whole PV thing.

                      However since you ask, and only FWIW, my opinion and usual advice is to:

                      1.) Avoid the big national firms, starting with Tesla. They're bottom feeders.
                      2.) Search out companies that are established, licensed, local electrical contractors that have been in business for at least 10 years or longer and have sold/installed PV for at least 5 of the last 10 years. Reason: They have survived in business and probably know what it takes to turn a profit, have other lines besides PV to continue in business, meaning they will probably be around after the solar boom is done, and are probably do quality, professional work. And, around here at least, since PV seems to be a cutthroat business, their prices are usually in line with the less professional outfits meaning a greater probability of more bang for your buck.
                      3.) get at least 3 quotes from qualified vendors.
                      4.) Negotiate tough but fair.
                      5.) NEVER share prices with competing vendors. You will only pay more. Think like a vendor. If you bite on the price matching con, you'll never pay one dollar less than the price you reveal. Sharp vendors know where the competition is pricewise anyway. You have no benefit in revealing any prices.

                      None of my $$, life or concern but if were you, or maybe if you knew some of what I think I might know, I'd examine my goals and if lowering an electric bill is high of that list of goals, I'd do a lot more homework on the most cost effective ways to achieve those goals, starting with an energy audit and use reduction before I looked into whether or not PV makes any sense for your application.

                      Take what you want of the above, scrap the rest.
                      +1 Good advice

                      Comment

                      • J.P.M.
                        Solar Fanatic
                        • Aug 2013
                        • 15015

                        #12
                        Originally posted by SunEagle

                        +1 Good advice
                        Opinions vary.

                        Comment

                        • peakbagger
                          Solar Fanatic
                          • Jun 2010
                          • 1566

                          #13
                          Its sure is heck of lot easier with asphalt shingle roofs or standing seam. IMHO you are setting yourself up for future roof leaks

                          If you go with their solar tile based roof they would strip all the tiles, fix the roof deck and then cover it with a waterproof underlayment and cover it with the solar tiles. Last thing I knew they increased pricing on the tiles by 30% as they were losing money on every roof and now require purchase of a battery.

                          BTW, The town adjacent to me has a 110 psf ground snow load with an added elevation factor. My town has measly 90 PSF.

                          Comment

                          • popeyerg
                            Junior Member
                            • Aug 2021
                            • 6

                            #14
                            i cancelled the order with Tesla. Looking at a few other companies locally in my area that are offering me the same panels that Tesla quoted me for, and their price is slightly higher then Tesla's quote. But according to everyone else I do not have to deal with the roof being replaced or any of that nonsense.

                            The next task is deciding to pay for the panels outright or utilize a loan/finance them. What is the general go to for this that people typically do with solar panels? Finance 20 years, pay low monthly rate and high interest total over the life of the financing (20 years for example) or just pay for them in cash/outright, bank the rebate and keep on moving?

                            Comment

                            • J.P.M.
                              Solar Fanatic
                              • Aug 2013
                              • 15015

                              #15
                              Originally posted by popeyerg
                              i cancelled the order with Tesla. Looking at a few other companies locally in my area that are offering me the same panels that Tesla quoted me for, and their price is slightly higher then Tesla's quote. But according to everyone else I do not have to deal with the roof being replaced or any of that nonsense.

                              The next task is deciding to pay for the panels outright or utilize a loan/finance them. What is the general go to for this that people typically do with solar panels? Finance 20 years, pay low monthly rate and high interest total over the life of the financing (20 years for example) or just pay for them in cash/outright, bank the rebate and keep on moving?
                              General consensus is more often to pay cash. Some of that thinking is probably influenced by the fact that the majority of residential PV is owned/leased/PPA'd by folks who can afford to pay cash for it. It trends to be the darling of the more affluent who have more cash. Want proof ? Next time you fly. notice how many array are in the suburbs vs, in large cities. Sort of a Q.E.D. IMO.

                              BTW: congrads on avoiding the Tesla scam.

                              Before you commit to anything, buy and read the book. Your ROI will probably be about 1000 % or better if you do choose to read it and still decide to go the PV route.

                              Good luck.

                              Comment

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