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  • #31
    Thanks for the interest! Not quite your neighborhood, but it is further north... 92129 zip, already well represented in PVO's team San Diego.

    The new house has a nice SSE facing roof:

    google.png

    A single row of panels ought to fit nicely there along the southern eave, with very good visibility of the horizon, and no sources of shade that I've noticed yet.

    There is an HOA, but other homes in the area have PV and solar thermal systems, so I don't expect it to add too much friction to the process.

    The old house is being rented out, so the Davis should be safe for now. I am actually keeping the electric bill in my name... changing the account ownership would wipe out all the credits the system has accumulated since May, which would be sad. On the TOU plan, with my EV, it only really generates credits during the summer months, but for the tenants, I've shifted it back to the DR tariff. Without an EV, the system should be oversized most of the year, even if they want to run a window AC aggressively this summer. The true-up is at the end of april, but the monthly consumption should start going net negative by feb/march so that might be a good time to try cutting the account over.

    As part of the process, the old house had to get a couple of appraisals. One of them ignored the PV system completely, the other included a $5000 adjustment for it. There does not seem to be much consensus on how the system should be valued. Very few of the houses we looked at while shopping had solar; we ran into one with a lease and one with solar thermal stealing the best part of the roof for PV.

    I have SolarEdge installed on that house, with which I have been satisfied. What I've been able to learn from the panel level data has helped tremendously in my understanding of these systems, and as a single story house with shingle roof (with access to each of the panels directly), I wouldn't mind going up to replace an optimizer if needed. On the new house, two stories with concrete tile, I have no desire to do any work up there. I'd lean toward a lower cost string inverter (probably Fronius Primo if I bought today), and whatever black framed panels I can find for a good price. I would be tempted to DIY... when I joined the forum, I had one kid, now I have 3. Time has gotten scarce. I would not shy away from using the same installer (through ButchDeal's company), but I've learned of a few others through the forum and in other networks that should be capable of doing nice work for a competitive price. It is a longer run from the array to where the inverter will be (service panel is on the NE corner), so finding a conduit path that is unobtrusive will be important to me. Previous owners left coax from an abandoned DirectTV install all over the roof and swiss-cheesing the walls... yuck.

    This house does not have an air conditioner, so the initial electric bills ought to be reasonable... I will get to see the true cost of charging the EV. Too many damn incandescents though...turning on my bathroom light uses more power than my whole house usually did before, and my workarounds to the power hog cable boxes won't work here (switching from Time Warner to AT&T). I've got a couple cases of LED's coming soon. Once I see what life is like through the hot months, I'll have a better idea of what size system to be looking at. Insulation (attic and wall) is *much* better than the old house, the difference between 1962 and 2003 standards, I guess.





    CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

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    • #32
      Originally posted by sensij View Post
      Thanks for the interest! Not quite your neighborhood, but it is further north... 92129 zip, already well represented in PVO's team San Diego.

      The new house has a nice SSE facing roof:

      [ATTACH=CONFIG]n323110[/ATTACH]

      A single row of panels ought to fit nicely there along the southern eave, with very good visibility of the horizon, and no sources of shade that I've noticed yet.

      There is an HOA, but other homes in the area have PV and solar thermal systems, so I don't expect it to add too much friction to the process.

      The old house is being rented out, so the Davis should be safe for now. I am actually keeping the electric bill in my name... changing the account ownership would wipe out all the credits the system has accumulated since May, which would be sad. On the TOU plan, with my EV, it only really generates credits during the summer months, but for the tenants, I've shifted it back to the DR tariff. Without an EV, the system should be oversized most of the year, even if they want to run a window AC aggressively this summer. The true-up is at the end of april, but the monthly consumption should start going net negative by feb/march so that might be a good time to try cutting the account over.

      As part of the process, the old house had to get a couple of appraisals. One of them ignored the PV system completely, the other included a $5000 adjustment for it. There does not seem to be much consensus on how the system should be valued. Very few of the houses we looked at while shopping had solar; we ran into one with a lease and one with solar thermal stealing the best part of the roof for PV.

      I have SolarEdge installed on that house, with which I have been satisfied. What I've been able to learn from the panel level data has helped tremendously in my understanding of these systems, and as a single story house with shingle roof (with access to each of the panels directly), I wouldn't mind going up to replace an optimizer if needed. On the new house, two stories with concrete tile, I have no desire to do any work up there. I'd lean toward a lower cost string inverter (probably Fronius Primo if I bought today), and whatever black framed panels I can find for a good price. I would be tempted to DIY... when I joined the forum, I had one kid, now I have 3. Time has gotten scarce. I would not shy away from using the same installer (through ButchDeal's company), but I've learned of a few others through the forum and in other networks that should be capable of doing nice work for a competitive price. It is a longer run from the array to where the inverter will be (service panel is on the NE corner), so finding a conduit path that is unobtrusive will be important to me. Previous owners left coax from an abandoned DirectTV install all over the roof and swiss-cheesing the walls... yuck.

      This house does not have an air conditioner, so the initial electric bills ought to be reasonable... I will get to see the true cost of charging the EV. Too many damn incandescents though...turning on my bathroom light uses more power than my whole house usually did before, and my workarounds to the power hog cable boxes won't work here (switching from Time Warner to AT&T). I've got a couple cases of LED's coming soon. Once I see what life is like through the hot months, I'll have a better idea of what size system to be looking at. Insulation (attic and wall) is *much* better than the old house, the difference between 1962 and 2003 standards, I guess.




      Thank you. Well, I'm more than a bit envious. You're in the cat bird seat for doing it right - conservation vs./+ R.E., especially with what you've picked up since arriving here. FWIW, some of the best and most fruitful experiences I had with conservation/solar were with a retrofit of my first home in the mid/late '70's onward.

      I'll not presume to suggest anything other than tightening up any dwelling is the single most cost effective thing that can be done, and solar, as you may/may not concur, about the last. Don't be surprised if you can easily knock back the prior owner's usage by at least 1/3 or more before solar. Maybe one other: Move the Davis ASAP. Other PVOutput users will appreciate it, and it'll be good data if/when solar does come into the picture. Morning fog/clearness indices may be more local but also of a more consistent diurnal pattern in the Carmel Valley area w/ valley fog holding on longer than @ higher elevations. Probably still better than where you were.

      Interesting info on appraisal value. Not unlike what I've heard/observed from appraisers/real estate folks/owners in my HOA.

      Don't be surprised if the electric usage at your old residence goes up, especially if the bill is included in the rent. Even if not, most folks use more power than you did. A lot more.

      In any case, congrads on the new digs, and good luck.

      Comment


      • #33
        Nice house. Just be careful not to fall off that 2 story roof.

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        • #34
          Yeah keep the updates coming!

          Comment


          • #35
            A quick update... the weather station is back online (still at the old house in 92111). PVOutput is showing the data because one of my scripts must be running amok and pushing old data for either consumption or generation. Wunderground looks good though:

            https://www.wunderground.com/persona...NDI580#history

            The new house consumption (from a Rainforest Eagle) is live. Standby power is around 240 W... higher than it was in the old house, but not unexpected. The AT&T equipment is probably responsible for most of the difference, but I haven't run around with the kill-a-watt yet to confirm. The built-in fridge is older (2003), and might be an opportunity to improve at some point. EV charging is still at 120 V until I get a new circuit wired in; it runs at 1440 W when I remember to set it to 12 A, otherwise it defaults to 8 (960 W). I'm hoping to get the higher voltage charging in place for a switch back to EV-TOU2 next month, to keep it entirely during the super off peak hours. The recessed lights have been replaced with LED's (Hyperikon BR30, 9 W, $5/ea), while the A19's (Phillips 461129, 8.5W, $1.25/ea) should swap out in a couple weeks when they arrive.

            http://pvoutput.org/intraday.jsp?id=36909&sid=46970

            I requested information from SDG&E on usage by the previous residents... not sure if they share it, but I'm curious.


            CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

            Comment


            • #36
              My apologies to those who had been following this system. (and thanks for the greeting in the other thread, J.P.M.) I have had a lot of trouble getting a stable wifi connection to the Solaredge inverter through my tenant's router, but seem to have found some settings that are making it more reliable. The PVOutput charts showing production and irradiance should be consistent again, although the production is now from the inverter, and not a revenue grade meter as it had originally been. It probably inflates the production by a few percent under typical conditions.

              The Davis has been up a year at this point, so it is probably time to get up on the roof and do some maintenance.. at a minimum... change the battery, clean the sensor, verify it is holding level. I was happy to see that even with the network trouble with the inverter, the data stream to Wunderground has remained intact.

              My tenants have been using more electricity than we did, even including my EV consumption. The TOU credits we had accumulated through the spring and early summer lasted until mid-December... I had switched them to the DR plan to try to stretch it out, but I'll need to take another look at there data when we get to the true-up in March and see if there is something different they could do to get more out of the system.

              I've started planning out the installation for my new house in 92129, and will probably move the Davis over once the PV system is operational.

              CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

              Comment


              • #37
                Originally posted by sensij View Post
                My apologies to those who had been following this system. (and thanks for the greeting in the other thread, J.P.M.) I have had a lot of trouble getting a stable wifi connection to the Solaredge inverter through my tenant's router, but seem to have found some settings that are making it more reliable. The PVOutput charts showing production and irradiance should be consistent again, although the production is now from the inverter, and not a revenue grade meter as it had originally been. It probably inflates the production by a few percent under typical conditions.

                The Davis has been up a year at this point, so it is probably time to get up on the roof and do some maintenance.. at a minimum... change the battery, clean the sensor, verify it is holding level. I was happy to see that even with the network trouble with the inverter, the data stream to Wunderground has remained intact.

                My tenants have been using more electricity than we did, even including my EV consumption. The TOU credits we had accumulated through the spring and early summer lasted until mid-December... I had switched them to the DR plan to try to stretch it out, but I'll need to take another look at there data when we get to the true-up in March and see if there is something different they could do to get more out of the system.

                I've started planning out the installation for my new house in 92129, and will probably move the Davis over once the PV system is operational.
                You're welcome. I note I was not the only one with greetings.

                With respect to the Davis on my roof, and FWIW only, I've noticed some irregularities with my rain gauge with respect to the tipping mechanism and it's accuracy. Long story, but using my old 500 ml graduated cylinder and funnel rain gauge sited next to (w/in ~ 10 ft.) the Davis, the Davis has settled into a rather consistent reading of ~ 74% - 78% of what I believe is the more accurate alternate measurement from the cylinder/funnel method.

                On cleaning the sensor, note that Davis recommends ethyl alcohol (and they specifically note NOT rubbing alcohol). I figure since it gets rainwater on it that water will also work. I clean the irradiance sensor w/distilled H2O and a VERY careful wiping with microscope lens paper (Baxter Healthcare Corp, but there are lots of other sources for that), carefully avoiding skin contact w/the sensor surface before each ongoing attempt at measuring array fouling. As best guess, after a changeout, the sensors start to drift after ~ 12-18 months, SWAG.

                FWIW, and mostly a no brainer, my (or most any) array's output current turns out to be about as good an indicator of irradiance as a pyranometer, within a narrow definition of the term, provided some reasonably sensible account is taken of the varying reflection loss from panel glazing as f(angle of incidence) and the output current adjustment for array temp.).

                I'll be looking through the CPUC doc. you referenced over the weekend. You're probably better versed than I with it at this time. I'm sort of the opinion and have been for some time that thinking of any stability, long or short term in any POCO rates may well be an exercise in futility. If so, the attachment you sent along might be thought of as the latest iteration of the inherently dynamic and thus ongoing attempt to flesh out what may be a foregone direction and little more. Good info, but similar to something I posted a couple of weeks ago, making long term commitments to solar and sizing based on the assumption that any rate structure be around at all, much less look the same in the future may be a bit shortsighted. Rates will always be somewhat dynamic. To think otherwise is na
                Last edited by J.P.M.; 02-17-2017, 04:52 PM.

                Comment


                • #38
                  Quick update.... my Tecolote Canyon weather station has been taken offline for relocation to zip code 92129. It has been in service for about 16 months, so probably a good time to do some maintenance before putting it back on the roof.
                  CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

                  Comment


                  • #39
                    Originally posted by sensij View Post
                    Quick update.... my Tecolote Canyon weather station has been taken offline for relocation to zip code 92129. It has been in service for about 16 months, so probably a good time to do some maintenance before putting it back on the roof.
                    Respectful suggestions:
                    - Change the batteries.
                    - Get a new solar sensor and calibrate it against the old one by comparing output for 10-15 mi. for each on either side of solar noon on a clear day. Last time I did that ( 06/14/16 - 06/27/16), average difference was ~ 2.1 % over 11 clear days with new sensor occupying the unused IR sensor slot. Just swap the leads at precisely solar noon at your location and be quick but deliberate about it.
                    I sent my original sensor back to Davis for recalibration but the results were useless as no curve or data came back with it. I'm sure it was the same one I sent to them. I plan on simply buying a new sensor every 2 yrs. and calibrating it against the most recent sensor as described above.
                    - Clean the rain gauge tipping cups and wipe off the small solar panel.

                    I clean the solar sensor daily but that's because I'm still trying to keep an eye on array fouling rates.
                    Last edited by J.P.M.; 06-23-2017, 04:46 PM.

                    Comment


                    • #40
                      I recently added a weather station to my system (along with communication to get internet to the remote ground site but that is another story). While I wanted to get a Davis, I decided to save $ and got a lower cost Ambient Weather 1400-IP setup.

                      https://www.wunderground.com/persona...OARS33#history


                      Last edited by tyab; 06-24-2017, 10:19 PM.

                      Comment


                      • #41
                        Originally posted by tyab View Post
                        I recently added a weather station to my system (along with communication to get internet to the remote ground site but that is another story). While I wanted to get a Davis, I decided to save $ and got a lower cost Ambient Weather 1400-IP setup.
                        That looks like a very nice weather station, but what's with the three headed monster mounting pole arrangement?
                        8.6 kWp roof (SE 7600 and 28 panels)

                        Comment


                        • #42
                          Originally posted by CharlieEscCA View Post
                          That looks like a very nice weather station, but what's with the three headed monster mounting pole arrangement?
                          My guess is that the outriggers at the pole top will keep an extension ladder from rotating around a single pole.

                          Comment


                          • #43
                            Originally posted by CharlieEscCA View Post
                            That looks like a very nice weather station, but what's with the three headed monster mounting pole arrangement?
                            The one on the right is for the optional commode with a view attachment.

                            Seriously, ladder stabilization is a common and heads' up reason for it, but perhaps also for other/future instrumentation.

                            Also, If the mounting is so tall it needs a ladder - nothing wrong with that, - but an often overlooked consideration is leveling. If the unsupported height of the mounting assembly is such that a ladder w/person causes it to deflect, the degree of that deflection with affect the instrument readings if not taken into account or cancelled out by aux. bracing to maintain free orientation when the instrument is installed or any time the level is checked. Been there, done that, gone through it w/ neighbors. Just sayin'.
                            Last edited by J.P.M.; 06-25-2017, 01:03 PM.

                            Comment


                            • #44
                              Originally posted by tyab View Post
                              I recently added a weather station to my system (along with communication to get internet to the remote ground site but that is another story). While I wanted to get a Davis, I decided to save $ and got a lower cost Ambient Weather 1400-IP setup.

                              https://www.wunderground.com/persona...OARS33#history

                              Questions:

                              1.) Shading of the array by the instrument ? Looks like morning shading may be present a good portion of the year.

                              2.) Do you know that any solar radiation data from that or most any weather station with solar irradiance measurement capabilities needs to be converted to plane of array irradiance before the data can be meaningfully used to check array performance ?

                              Comment


                              • #45
                                Originally posted by tyab View Post
                                I recently added a weather station to my system (along with communication to get internet to the remote ground site but that is another story). While I wanted to get a Davis, I decided to save $ and got a lower cost Ambient Weather 1400-IP setup.

                                https://www.wunderground.com/persona...OARS33#history

                                Questions:

                                1.) Won't the instrument shade the array in the A.M a good portion of the year ?

                                2.) Do you know that what are most always global horizontal irradiance (G.H.I) measurements from a weather station need to be converted to plane of array (P.O.A.) irradiance before they can be used to check an array's performance ?

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