Announcement

Collapse
No announcement yet.

North facing Panels

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #46
    Originally posted by rsilvers View Post

    They had two south-facing surfaces covered also. Maybe they were going to stop there, but realized that with the SRECs, also doing the north was better over 10 years than not also doing the north.

    So they probably still made a better decision than the dozens of perfect south-facing wide-open roofs I saw today that had no solar at all.
    One of those "every situation is different, and most of'm ain't mine" types of situation. Just seems quite unusual overall to the eye attached to an informed brain is all.

    Comment


    • #47
      Time lapse photography might have been able to do it. I wonder if an old cellphone running a timelapse app might become an important sales tool.

      Comment


      • #48
        Originally posted by J.P.M. View Post

        One of those "every situation is different, and most of'm ain't mine" types of situation. Just seems quite unusual overall to the eye attached to an informed brain is all.
        An SREC2 is worth about $250. The electricity is worth about $230 per megawatt. So even north facing panels making half the power are still as good as south-facing panels in some other states.

        So if the logic seems dumb, it is only because the incentives are unusually good (and arguably unfair to non-solar users).
        Last edited by rsilvers; 05-11-2016, 11:21 AM.

        Comment


        • #49
          Originally posted by ButchDeal View Post
          In his area the sun will rise just north of due east and set a few degrees north of west.
          And as you know, only for half the year in any area north of the equator. Additionally, as I'm sure you know, most any insolation on an array of any orientation at early/late hrs. will be small enough to be ignored anyway.

          Comment


          • ButchDeal
            ButchDeal commented
            Editing a comment
            yep, but no convincing the customer because he is "in the industry" and knows best.
            I told him we would not install on the north over the south and if that is what he wants, he should find another installer.

            He stated that he thought he spoke to them all and was going to have to do a self install.

        • #50
          Originally posted by compchat View Post
          Had a system installed with two inverters and 42 panels. Some were placed on south roof and some were placed on the North roof. The system is rated 11 KW D.C. with two inverters.

          I live in Southern California and currently the 23 Southern roof panels in full sun without clouds generate around 3700 watts during peak hours . It has a 6 KW inverter.

          The North Roof is generating about 800 watts with 19 panels (265) under same circumstances.

          Well, installer shouldn't have done that, and do not know if you can get any money back, but now you learned of your mistake, all is not lost. I would, if I was you, take those northern panels down, and mount them on a dual axis tracker in your backyard. And you will way ahead in the power making department, perhaps you can even reuse northern rack with hot water panels, granted you will run in same out of sun axis problem, but you don't use hot water like you do electricity....

          Comment


          • #51
            Just to close this off and give some prospective owners coming to this thread for some advice about West-facing panels vs North/South/East, I've done some calculations based on PVWatts data and SCE TOU rates and West-facing panels can be nearly as cost-effective as South-facing panels when you take TOU rates into consideration.

            For example, an 2.5kW system where I live in SoCal can produce the following:

            -- South-facing: 4250kWh and $780 in NEM credits
            -- West-facing: 3725kWh and $770 in NEM credits
            -- East-facing: 3576kWh and $610 in NEM credits

            As you can see, while South-facing panels do indeed produce the most energy and NEM credits, West-facing panels are within 1.5% monetarily, despite the fact that they produce over 12% less energy. East-facing panels, while producing similar amounts of energy to West-facing panels, don't even come close to generating the same amount of NEM credits.

            I didn't even bother doing North-facing when I did the calculations as annual production would be abysmal, in addition to receiving no "help" from TOU rate structures.

            In my eyes, West-facing panels are just as good as South-facing panels from a financial standpoint. East-facing panels are not nearly as "lucrative," and North-facing panels should never even be considered (I'm obviously talking about the Northern hemisphere and not near the equator).

            If you are the type to be concerned about your carbon footprint (due to offsetting the coal power plants during times of the day with of high energy demand), then West-facing panels are a no-brainer. This is a reason why certain municipalities are giving credits to home builders that provision for solar panels on West-facing roofs.

            Comment


            • #52
              There must be a time of use billing. If time of use was not in the equation east and west would be 12% less than south. is that what you are saying?

              Comment


              • #53
                Originally posted by SolarFuture View Post
                Just to close this off and give some prospective owners coming to this thread for some advice about West-facing panels vs North/South/East, I've done some calculations based on PVWatts data and SCE TOU rates and West-facing panels can be nearly as cost-effective as South-facing panels when you take TOU rates into consideration.

                For example, an 2.5kW system where I live in SoCal can produce the following:

                -- South-facing: 4250kWh and $780 in NEM credits
                -- West-facing: 3725kWh and $770 in NEM credits
                -- East-facing: 3576kWh and $610 in NEM credits

                As you can see, while South-facing panels do indeed produce the most energy and NEM credits, West-facing panels are within 1.5% monetarily, despite the fact that they produce over 12% less energy. East-facing panels, while producing similar amounts of energy to West-facing panels, don't even come close to generating the same amount of NEM credits.

                I didn't even bother doing North-facing when I did the calculations as annual production would be abysmal, in addition to receiving no "help" from TOU rate structures.

                In my eyes, West-facing panels are just as good as South-facing panels from a financial standpoint. East-facing panels are not nearly as "lucrative," and North-facing panels should never even be considered (I'm obviously talking about the Northern hemisphere and not near the equator).

                If you are the type to be concerned about your carbon footprint (due to offsetting the coal power plants during times of the day with of high energy demand), then West-facing panels are a no-brainer. This is a reason why certain municipalities are giving credits to home builders that provision for solar panels on West-facing roofs.
                Location, location, location. Probably and generally a trend in So. CA, and I,m not disputing the particular findings, but not always necessarily as shown, depending on location and POCO T.O.U. tariffs at that locatiop. If west facing is the only choice, so be it. Around here West facing is probably close, but still the 2d best. Again, every situation will be different, as well as the idea that not every choice is exactly a 180 or 270 deg. azimuth. BTW, T.O.U. as well as all tariffs will change over time. Knowing that, and if given the choice, I'll take max. production facing south and take my chances.

                Comment


                • #54
                  Originally posted by john phillips View Post
                  There must be a time of use billing. If time of use was not in the equation east and west would be 12% less than south. is that what you are saying?
                  That's one factor. A second factor is that in Southern California, during the best solar months, we tend to get low clouds (June gloom) from morning until noon or so. Thus orienting them southwest rather than west maximizes production during peak months.

                  Comment


                  • #55
                    Originally posted by jflorey2 View Post
                    That's one factor. A second factor is that in Southern California, during the best solar months, we tend to get low clouds (June gloom) from morning until noon or so. Thus orienting them southwest rather than west maximizes production during peak months.
                    That's definitely been true a few days lately.

                    Comment


                    • #56
                      Originally posted by DanKegel View Post

                      That's definitely been true a few days lately.
                      Is that type of weather typical for southern CA?

                      Comment


                      • #57
                        Originally posted by SunEagle View Post
                        Is that type of weather typical for southern CA?
                        For May and June definitely. Usually it ends in July/August, but this has been a strange year.

                        Comment


                        • #58
                          Originally posted by jflorey2 View Post
                          For May and June definitely. Usually it ends in July/August, but this has been a strange year.
                          Damn weather is going to make a lot of the estimations from pvwatts wrong. Hope it clears up for you guys.

                          Comment


                          • #59
                            Originally posted by SunEagle View Post

                            Damn weather is going to make a lot of the estimations from pvwatts wrong. Hope it clears up for you guys.
                            The TMY files that PVWatts uses are reasonably aware of the seasonal patterns. NREL's data suggests that the modeled output for any particular month may vary by 30% from actual output, but those variances tend to cancel out over the year. I'm at about 80% of my June 2015 production with another week to go, so this year doesn't seem too different than last.
                            CS6P-260P/SE3000 - http://tiny.cc/ed5ozx

                            Comment


                            • #60
                              The weather is what it is, and it's not climate. Climate's what you expect. Weather is what you get. Solar models use what's probably best described as climate modeling.

                              As Sensij notes, and as PVWatts info screens discuss, that, or any other model cannot estimate any short period's solar production any more accurately than a weather forecast. I would suggest however that while PVWatts states that monthly results from the model can vary by up to +/- 30 % vs. for an actual month, yearly values can also vary by as much as +/- 10%.

                              I've got a clear sky climate model that estimates my array will produce about 11,140 kWh/yr. using Miramar TMY3 temp. & wind data and the HDKR model for clear sky irradiance. The same model, using TMY3 Miramar data including irradiance comes up with 9506 kWh/yr., or 85.4% of a clear sky.

                              My array has been live since solar noon, 10/17/2013. zip 92026, about 20 airline miles from the coast. I keep a running total on the 365 days of prior array production since 10/18/2014. The lowest prior 365 day running total is 9,033 kWh/365 days. The highest prior 365 day running total is 9,644 kWh/365 days. Average, 9,298 kWh/prior 365 days. Std. dev. for prior 365 day running total is 187.3.

                              So far the array has produced 24,628 kWh. the theoretical clear sky production might be about 30,170 kWh. 24628/30170 = 81.6%, or about 3.8% shy of model est. I've not got the #'s handy for actual clearness index at my location vs. the clearness index for the TMY3 data, as it's not been a priority, but I'm working on it.

                              BTW, I believe there's a lot of desert in SO. CA that doesn't see a lot of morning/coastal fog or May/June cloudiness. To say or imply all of SO. CA climate is described by what happens relatively near the coast may not be entirely accurate. My location is ~ 1,400 ft. above sea level and while I get some morning fog, it almost always burns off by 0800 or so. I watch the fog retreat to the coast as I do my morning rants. Just sayin.
                              Last edited by J.P.M.; 06-25-2016, 12:59 AM. Reason: Spelling.

                              Comment

                              Working...
                              X