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  • #16
    Originally posted by bcroe View Post

    Is that for tracking, or for vertical angle, or for anything past vertical? Here nothing is under warrantee
    for very long, interferes with activities. Bruce Roe
    If it exposes the back to the sky going beyond vertical would do that.
    NABCEP certified Technical Sales Professional

    [URL="http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design"]http://www.solarpaneltalk.com/showth...Battery-Design[/URL]

    [URL]http://www.calculator.net/voltage-drop-calculator.html[/URL] (Voltage drop Calculator among others)

    [URL="http://www.gaisma.com"]www.gaisma.com[/URL]

    Comment


    • #17
      Instead of a tracker, just use more panels to take advantage of the prime solar-insolation hours you do have. Off-prime hours when the sun is low during the early morning and late afternoon are weak, so that's why it may seem incredible in places where there are 8 hours of daylight, that according to calculations only has 2 hours of *quality* usable sunlight power.

      Increasing your stationary panel wattage would probably be cheaper and easier to implement.

      Comment


      • #18
        Originally posted by PNjunction View Post
        I
        Increasing your stationary panel wattage would probably be cheaper and easier to implement.
        Except for the part about getting the snow off....
        SunnyBoy 3000 US, 18 BP Solar 175B panels.

        Comment


        • #19
          Originally posted by PNjunction View Post
          Instead of a tracker, just use more panels to take advantage of the prime solar-insolation hours you do have. Off-prime hours when the sun is low during the early morning and late afternoon are weak, so that's why it may seem incredible in places where there are 8 hours of daylight, that according to calculations only has 2 hours of *quality* usable sunlight power.

          Increasing your stationary panel wattage would probably be cheaper and easier to implement.
          Yes it only took me 5 months to increase panels that way. Here in northern IL, with snow and E-W panels, Monday production calculated out to 7.8 equivalent sun hours (117 KWH). Solving the snow issues may take years, but getting all panels near vertical should help.
          Bruce Roe
          Last edited by inetdog; 03-04-2014, 11:44 PM.

          Comment


          • #20
            quote who?

            That is interesting. My post is missing, but SOMEBODY else quoted part of it, commented
            on it, and its all credited to me. Bruce Roe

            Comment


            • #21
              Originally posted by bcroe View Post
              That is interesting. My post is missing, but SOMEBODY else quoted part of it, commented
              on it, and its all credited to me. Bruce Roe
              Mea Culpa. I hit the wrong button when trying to comment/reply.
              Not sure how to fix it up again, but I will try.

              OK, I think it is all better now.
              Sorry about that....
              Last edited by inetdog; 03-04-2014, 11:45 PM.
              SunnyBoy 3000 US, 18 BP Solar 175B panels.

              Comment


              • #22
                Originally posted by bcroe View Post
                Yes it only took me 5 months to increase panels that way. Here in northern IL, with snow and E-W panels, Monday production calculated out to 7.8 equivalent sun hours (117 KWH). Solving the snow issues may take years, but getting all panels near vertical should help.
                Bruce Roe
                Very impressive and giving some additional hope to those who are not all that far north.
                SunnyBoy 3000 US, 18 BP Solar 175B panels.

                Comment


                • #23
                  Originally posted by bcroe View Post
                  Solving the snow issues may take years, but getting all panels near vertical should help.
                  Bruce Roe
                  Me again trying to think outside the box,
                  Have you looked into radiant heating flooring coils to see if they could be mounted under or around your panels?
                  I have no idea how efficient they are or even if they could be used outside.

                  Comment


                  • #24
                    Melting snow

                    Originally posted by FUN4ME View Post
                    Me again trying to think outside the box,
                    Have you looked into radiant heating flooring coils to see if they could be mounted under or around your panels?
                    I have no idea how efficient they are or even if they could be used outside.
                    My intuitive feeling, this would be hopelessly complex & energy inefficient. The approach
                    being considered (another thread, Panel Sensitivity) is to directly heat the panels with
                    external power to them. I have some doubt that even that will be efficient enough to
                    be justified. Next year i might set up a couple panels and try this, the second panel
                    for comparison. Following summer, see if the heating experiment reduced the
                    performance of the heated panel, compared to the reference panel. Meantime, the
                    immediate change will be to get panels mostly vertical, later this year.

                    Bruce Roe

                    Comment


                    • #25
                      Originally posted by bcroe View Post
                      Yes it only took me 5 months to increase panels that way. Here in northern IL, with snow and E-W panels, Monday production calculated out to 7.8 equivalent sun hours (117 KWH). Solving the snow issues may take years, but getting all panels near vertical should help.
                      Bruce Roe
                      Decided to graph the level of my AC energy output over a sunny + cool day.
                      Clipping is minimal, probably will stop with warmer weather & snow melted.

                      This doesn't look much like the usual "bell curve". Power rises very fast as
                      sun hits the east facing panels. Toward mid day the main power comes from
                      south facing, and then transfers to west facing approaching sunset. It would
                      be even closer to "rectangular" if I didn't have any shading issues at
                      extremes of the sun day. Best day so far is 125 KWH.

                      The selection of non south panel orientations was chosen by guess & by golly,
                      no proper simulation. It was based on the panels and space I had, and what
                      one guy might be able to throw up in a month. For all that, it is working very
                      well. In addition, output in cloudy weather (light dispersed) is way up; a
                      typical overcast day produces 60 to 90 KWH.

                      There is probably room for improvement here. Need to understand some
                      serious simulation tools. Generally goals are to set panels to: minimize snow
                      accumulation; minimize clipping in good sun all year; and bring up power for
                      sun day beginning & end times. Using additional panels "inefficiently" to do
                      this, will bring up power during clouds, etc, rather common here. Bruce Roe
                      Attached Files

                      Comment


                      • #26
                        Last year the sun was beaming down, but the power co didn't put in my net
                        meter till Aug. This year everything is running, but clouds just won't go away.
                        On Monday I saw SNOW falling????

                        Despite that, had mostly sunny today, spotty dark clouds. If we ever have
                        a clear day this summer, I do hope to see a day of 150 KWH. Regardless,
                        it did produce a new record today, 144 KWH squeezed through 15 KW of
                        inverters, 9.6 SUN HOURS in a day. Bruce Roe

                        Comment


                        • #27
                          Originally posted by bcroe View Post
                          Last year the sun was beaming down, but the power co didn't put in my net
                          meter till Aug. This year everything is running, but clouds just won't go away.
                          On Monday I saw SNOW falling????

                          Despite that, had mostly sunny today, spotty dark clouds. If we ever have
                          a clear day this summer, I do hope to see a day of 150 KWH. Regardless,
                          it did produce a new record today, 144 KWH squeezed through 15 KW of
                          inverters, 9.6 SUN HOURS in a day. Bruce Roe
                          Bruce, that is impressive. That gives the PVOutput.org definition of efficiency (kWh divided by kW DC) of approximately 7.68 kWh/kW to 8.64 kWh/kW (assuming inverter efficiency of between 80-90%) putting you at the top 1% of the efficient pv systems in PVOutput. Do you have a PVOutput account and if so, may I look at that account?

                          Comment


                          • #28
                            Originally posted by gregvet View Post
                            Bruce, that is impressive. That gives the PVOutput.org definition of efficiency (kWh divided by kW DC) of approximately 7.68 kWh/kW to 8.64 kWh/kW (assuming inverter efficiency of between 80-90%) putting you at the top 1% of the efficient pv systems in PVOutput. Do you have a PVOutput account and if so, may I look at that account?
                            Of course the reason the Bruce gets some many hours of "producing sunlight" in one day is due the way he has set up his panels. One group is facing East, another South and a third West. So for most of the day at least one group is producing.

                            It is a very impressive system. Great job Bruce.

                            Comment


                            • #29
                              Originally posted by gregvet View Post
                              Bruce, that is impressive. That gives the PVOutput.org definition of efficiency (kWh divided by kW DC) of approximately 7.68 kWh/kW to 8.64 kWh/kW (assuming inverter efficiency of between 80-90%) putting you at the top 1% of the efficient pv systems in PVOutput. Do you have a PVOutput account and if so, may I look at that account?
                              As the longest day gets closer, the next 3 predicted clear days might get me that
                              10 SUN HOUR day. I suppose that means my inverters will only last 5 years instead
                              of 10, maybe can learn to fix them. I have a spare.

                              I don't have an account on line, the numbers appear on a pair of 7.5 KW Fronius
                              inverters, logged regularly in a notebook. If you click bcroe, view profile, about me,
                              you can find my PHOTOBUCKET link showing details in sub albums under album
                              ENERGY CONSERVATION.

                              With the most straightforward PV system located in sunny southern Cal, it might be
                              fine to list a system as so many KW. I prefer to list DC and AC limits. That starts
                              to matter when adding panel strings to compensate for the weather here in cloud
                              land. So a simple ratio of those numbers isn't the whole story.

                              I have ENOUGH AC capacity, and no way to expand it without replacing EVERYTHING.
                              The OBJECTIVE is to keep the inverters loaded as much of the time as possible. So
                              panels aimed at rising, midday, and setting sun do it, and bring mild overcast output
                              up to 60% to 80% of max. I have seen 4KW during a rain storm. A year will do at
                              least 25 Megawatt hour.

                              BUT if you take my DC capacity (29 KW & counting) against AC output, its a very low
                              number. That because the sun never hits all panels at the same time, and if it did,
                              there is no way to invert it all. So PVOutput using DC installation might put me in
                              the basement, I don't care. I'm not sure how your calculation worked.

                              I don't see a really good rating system for this sort of design, never heard this type
                              discussion before construction. But minimum panels initially were only a quarter of
                              the system cost, and more are a really good investment in cloud land. Bruce Roe

                              Comment


                              • #30
                                Originally posted by bcroe View Post
                                As the longest day gets closer, the next 3 predicted clear days might get me that
                                10 SUN HOUR day. I suppose that means my inverters will only last 5 years instead
                                of 10, maybe can learn to fix them. I have a spare.

                                I don't have an account on line, the numbers appear on a pair of 7.5 KW Fronius
                                inverters, logged regularly in a notebook. If you click bcroe, view profile, about me,
                                you can find my PHOTOBUCKET link showing details in sub albums under album
                                ENERGY CONSERVATION.

                                With the most straightforward PV system located in sunny southern Cal, it might be
                                fine to list a system as so many KW. I prefer to list DC and AC limits. That starts
                                to matter when adding panel strings to compensate for the weather here in cloud
                                land. So a simple ratio of those numbers isn't the whole story.

                                I have ENOUGH AC capacity, and no way to expand it without replacing EVERYTHING.
                                The OBJECTIVE is to keep the inverters loaded as much of the time as possible. So
                                panels aimed at rising, midday, and setting sun do it, and bring mild overcast output
                                up to 60% to 80% of max. I have seen 4KW during a rain storm. A year will do at
                                least 25 Megawatt hour.

                                BUT if you take my DC capacity (29 KW & counting) against AC output, its a very low
                                number. That because the sun never hits all panels at the same time, and if it did,
                                there is no way to invert it all. So PVOutput using DC installation might put me in
                                the basement, I don't care. I'm not sure how your calculation worked.

                                I don't see a really good rating system for this sort of design, never heard this type
                                discussion before construction. But minimum panels initially were only a quarter of
                                the system cost, and more are a really good investment in cloud land. Bruce Roe
                                Bruce: Are your panels fixed or moveable ?

                                Comment

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