Finally installing PV on my roof in LA: day 1

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  • J.P.M.
    Solar Fanatic
    • Aug 2013
    • 15036

    #91
    Originally posted by DanKegel
    Yep, I'm worried about temperature effects.

    And I'm worried about solaredge monitoring accuracy.

    I might start by just waiting a week or two, then extract data for each panel for each day from the logs,
    write a filter to skip days without full sun,
    grab ambient temperature data from the nearest weather station,
    and see if I can get a repeatable and stable measure of corrected peak and total power in full sun.
    If I get ambitious, I might add temperature sensors glued to the backsides of the panels.

    I expect doing this right is harder than it sounds.
    The temp. of a panel is dependent on more things than ambient airtemp. alone. To have any hope of a reasonable dart throw at some meaningful data, you'll need an onsite weather station, and some knowledge of what data is important as well as what to do with it.

    Desire for answers and intellectual curiosity are admirable qualities. Those qualities without the knowledge required to use them is like a powerful locomotive with no flanges on the wheels.

    IMO only, you need not only flanges, but track as well.

    The amb. temp. on your roof will be quite different than the nearest weather station.

    The solaredge monitoring accuracy, like most other panel monitoring is probably less than any of the variability in your other instrumentation. In any case, unless you have some way to measure or estimate that (monitoring) accuracy, it's a moot point.

    Take readings at min. incidence angle on cloudless days. They will give the best chance of max. irradiance and will have the least minute/minute variation.

    Temp. sensors "glued" to the backside of panels is pretty much useless without knowing how to estimate modifications to the readings. Their mass, especially relative to a PV panel, the way they change the heat transfer film coeff. between the air and the panel surface, the thermal resistance between the sensor and the surface through the attachment method - the "glue", as well as several other things, make any readings obtained via attached sensors, again without adjusting the raw data, pretty much useless. Do what you want, but know there's more going on and more things required than you know about.

    Curiosity and desire for information by themselves do not guarantee meaningful results that reflect some accurate, useful and repeatable version of reality.

    Comment

    • DanKegel
      Banned
      • Sep 2014
      • 2093

      #92
      Originally posted by J.P.M.
      Those qualities without the knowledge required to use them
      Yes, I understand you think I'm an idiot.

      Comment

      • J.P.M.
        Solar Fanatic
        • Aug 2013
        • 15036

        #93
        Originally posted by DanKegel

        Yes, I understand you think I'm an idiot.
        One more time: Don't do my thinking for me.

        FWIW, I have a rather unpopular opinion in that I happen to think most people are about equally intelligent. The difference is mostly what they do with the opportunities they're given. Lots more to that, but it's off topic.

        As for any abilities you may have, whatever they may be, I do not believe you have the basics of engineering and science required to make the types of observations you seem to come up with. That makes what you write about technical issues less accurate and therefore less valuable, not to mention more troublesome for those of us (like me in this case) who clean up your perhaps well meaning spoor that does more harm than good. I'll give you the benefit of the doubt that you do that out of ignorance.

        Sort of reminds me of the story about French researchers investigating frog physiology. They get a frog and fire a starting pistol off behind the frog, frightening it. They record it jumps 10 feet when the pistol is fired and report it as such in the research findings. They then cut one of the frog's back legs off, fire the gun once more and report that the frog jumps 5 feet. Next, they cut the frog's other back leg off and repeat the pistol firing. The frog doesn't jump. The research finding and the report states: Removing a frog's back legs causes deafness in frogs.

        Know what your doing and study what's required before you assume you know something. I forgot more about what you seem to be attempting than I expect you'll know for some time. Learn from the mistakes of others. You won't live long enough to make them all yourself.

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

        Comment

        • DanKegel
          Banned
          • Sep 2014
          • 2093

          #94
          Originally posted by J.P.M.
          I do not believe you have the basics of engineering and science required to make the types of observations you seem to come up with.
          Yes, you've said that many times. I'm not sure on what basis you came to that conclusion.

          Comment

          • J.P.M.
            Solar Fanatic
            • Aug 2013
            • 15036

            #95
            Originally posted by DanKegel

            Yes, you've said that many times. I'm not sure on what basis you came to that conclusion.
            I'll enlighten you: Most everything you've written. IMO only, you seem to be better at repeating other's cherry picked ideas that fit your preconceived agenda than serious original contributions.

            When you do have something perhaps original such as now, it's full of poor thinking as anyone versed in the subject can see.

            I like nice clothes, but I know nothing about tailoring. So, I try not to bloviate about tailoring to someone who knows how to make clothes as I'm mostly ignorant about the craft and profession.

            Take the hint and the advice and do with it as you please.
            Last edited by J.P.M.; 03-30-2016, 08:26 PM.

            Comment

            • DanKegel
              Banned
              • Sep 2014
              • 2093

              #96
              Originally posted by J.P.M.
              When you do have something perhaps original such as now, it's full of poor thinking as anyone versed in the subject can see.
              Are you saying that the basic idea of trying to understand and measure the front and back side contributions to the output of a handful of bifacial panels is poor thinking?

              Comment

              • solar pete
                Administrator
                • May 2014
                • 1840

                #97
                now now, you two play nice or you will have to go to your rooms.

                Comment

                • DanKegel
                  Banned
                  • Sep 2014
                  • 2093

                  #98
                  Dad! Jimmy's accusing me of shooting frogs again!

                  Comment

                  • J.P.M.
                    Solar Fanatic
                    • Aug 2013
                    • 15036

                    #99
                    Originally posted by DanKegel

                    Are you saying that the basic idea of trying to understand and measure the front and back side contributions to the output of a handful of bifacial panels is poor thinking?
                    No, and that you would say that from what I've written says a lot to me about your lack of knowledge about that subject. I'm writing that you lack the knowledge and experience to do it in a way that that will yield meaningful results that can be a useful contribution to the existing body of knowledge.

                    Comment

                    • DanKegel
                      Banned
                      • Sep 2014
                      • 2093

                      #100
                      Originally posted by J.P.M.
                      . I'm writing that you lack the knowledge and experience to do it in a way that that will yield meaningful results that can be a useful contribution to the existing body of knowledge.
                      A testable prediction! Let's see what happens.

                      Comment

                      • J.P.M.
                        Solar Fanatic
                        • Aug 2013
                        • 15036

                        #101
                        Originally posted by solar pete
                        now now, you two play nice or you will have to go to your rooms.
                        Have I been unprofessional, rude or personally abusive, or just straight in what I write ?

                        This forum is at least partially about opinions right ? I believe if you look at what I write, you'll find it's mostly responses in the form of information I've leaned or opinions I've formed over an engineering career, with some lame attempts at a bit of PG-13 humor thrown in 1X/awhile. It's not about what I think of someone as a person, and certainly not about personal attacks or dislike of someone. Seems to me to dislike someone, you must know something about them. I don't know any posters to this forum.

                        Dan's attitude and M.O. are of a type I've seen all my life, and spent more time than I'd like correcting their ignorant mistakes. Where I believe those attitudes and M.O.'s convey incorrect or dangerous information, I'll say so and/or offer counter opinions as warranted. I only do so in areas where I think I know what I'm talking about.

                        I do not believe I've been rude. I do believe I've offered constructive criticism as well as a some a lot of information some may have found useful, and have freely shared some of what I know about solar energy.

                        Having had a few minor admonitions from moderators in the somewhat distant past, but not much else, I plan no changes to the way I operate on this forum. If you disagree, let me know and I'll leave.

                        Comment

                        • solar pete
                          Administrator
                          • May 2014
                          • 1840

                          #102
                          Originally posted by J.P.M.

                          Have I been unprofessional, rude or personally abusive, or just straight in what I write ?

                          This forum is at least partially about opinions right ? I believe if you look at what I write, you'll find it's mostly responses in the form of information I've leaned or opinions I've formed over an engineering career, with some lame attempts at a bit of PG-13 humor thrown in 1X/awhile. It's not about what I think of someone as a person, and certainly not about personal attacks or dislike of someone. Seems to me to dislike someone, you must know something about them. I don't know any posters to this forum.

                          Dan's attitude and M.O. are of a type I've seen all my life, and spent more time than I'd like correcting their ignorant mistakes. Where I believe those attitudes and M.O.'s convey incorrect or dangerous information, I'll say so and/or offer counter opinions as warranted. I only do so in areas where I think I know what I'm talking about.

                          I do not believe I've been rude. I do believe I've offered constructive criticism as well as a some a lot of information some may have found useful, and have freely shared some of what I know about solar energy.

                          Having had a few minor admonitions from moderators in the somewhat distant past, but not much else, I plan no changes to the way I operate on this forum. If you disagree, let me know and I'll leave.
                          Geez, .....perhaps I should have writen in comic sans, I look forward to your 5 paragraph response

                          Comment

                          • DanKegel
                            Banned
                            • Sep 2014
                            • 2093

                            #103
                            Originally posted by J.P.M.
                            Have I been unprofessional, rude or personally abusive, or just straight in what I write ?
                            Well, in



                            you called my posts "tripe", and let me just point out, you can't spell disrespect without tripe

                            Comment

                            • J.P.M.
                              Solar Fanatic
                              • Aug 2013
                              • 15036

                              #104
                              Originally posted by DanKegel

                              Well, in



                              you called my posts "tripe", and let me just point out, you can't spell disrespect without tripe
                              Tripe: Something rude, worthless or offensive.

                              Reads to me like I was expressing an opinion about what you posted. That's probably an apt description of how I feel about the content of a lot of your posts. I'll probably write something similar in the future if, IMO, you post something that I believe to be incorrect, misinformed or dangerous. Think of it as a public service.This is after all a place to exchange opinions as well as information. I don't see calling something tripe as disrespectful but rather straight, to the point and maybe a public service to flag the solar ignorant that someone thinks something may be amiss with something you posted.

                              In the end, it's all opinion. I have mine. You have yours.

                              I try very hard, sometimes with limited success, to stay out of technical areas where I'm ignorant to avoid possibly misinforming others with incorrect, time wasting or possibly dangerous information. I believe that's respectful. Think about that if you care to.

                              Because you may not like what you read does not make it rude, just something you don't agree with.

                              You again have the last word in this latest waste of electrons.

                              Comment

                              • DanKegel
                                Banned
                                • Sep 2014
                                • 2093

                                #105
                                Originally posted by J.P.M.
                                Reads to me like I was expressing an opinion about what you posted. That's probably an apt description of how I feel about the content of a lot of your posts.
                                Right - you said "You keep spreading your tripe and I'll continue to call it tripe". But that goes beyond just criticizing one post; you consistently state that my posts are worthless, that I don't know what I'm talking about. You're rather aggressive about it, too.

                                I think for both our sakes' I should use the forum's "ignore" feature to ignore your posts in the future; that should save us both a lot of trouble.

                                If JPM ever decides to stop spam-replying every one of my posts with "Dan, I respectfully suggest that you stop posting ignorant drivel", let me know, and I'll remove him from my ignore list.
                                Last edited by DanKegel; 03-31-2016, 01:17 PM.

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