Building Reserve and Using KWH

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  • J.P.M.
    Solar Fanatic
    • Aug 2013
    • 14939

    Originally posted by bcroe
    This area usually dodges most of that, but we
    did get hit with -10F temps and wind giving a chill of -30F (how much
    of that applies to buildings?).
    Bruce Roe
    Bruce:

    Strictly speaking, since wind chill is defined as what the air temp. feels like to exposed human skin, not much, that is, zero.

    However, dwelling heat loss (or gain) is affected by dry bulb temp. difference inside to outside a dwelling and wind velocity as well as solar input and the radiant effects of the surroundings (including the effective sky temp.)
    The higher the wind velocity is on a building element (with effects for wind direction relative to the building element under consideration thrown in), the greater the heat transfer component due to wind vector will be.

    I believe I understand the physiological concepts involved with the concept of wind chill, but I always thought wind chill was mostly a bunch of B.S. hype whose only use was/is to make people feel more catastrophic.

    If I was out shoveling my driveway in Buffalo w/10F. air temp. and 30 MPH wind (which was pretty common), about the only parts of my body exposed to the air was my nose and eyes. Kind of like who in their right mind opens a window in a blizzard, who's out running around outside butt naked in the cold anyway ?

    Give me the dry bulb temp. and the wind vector and I'll dress appropriately for the circumstances.

    Comment

    • bcroe
      Solar Fanatic
      • Jan 2012
      • 5203

      Originally posted by bcroe
      So another year, Nyle periodically says the unit will
      be available, but once again failed to deliver it. Bruce Roe
      Once again Nyle announced the e8 water heating heat pump adapter,
      might soon be available. It is still in the process of being Energy Star
      certified, UEF tested, UL tested, and other things. If I ever get one,
      the energy reserve might be exhausted, better than giving it away.

      Although this property was purchased with an eye to eliminating the
      building maintenance (painting, etc), there was one standard roof on
      the house. The shingles, facia, and rain gutters got replaced in 2021,
      but now it was so slippery I could hardly go up there. As discussed
      earlier, clamps to attach are quite expensive, $5 and up each. After
      a bit of experimentation, I came up with this DIY version, using the
      same 6061 aluminum and 18-8 hardware as the ground mounts. I
      put some special conductive tape over the roof ridge first, to avoid
      scratching the paint too much.

      This is not normally under much stress, it just gives me a handhold
      and a place to connect a safety strap. Note the foot friction strips
      which stick to the roof. Bruce Roe

      IMGP2436.jpg
      Last edited by bcroe; 05-04-2023, 12:14 AM.

      Comment

      • DanS26
        Solar Fanatic
        • Dec 2011
        • 976

        hey Bruce...just wondering how those 7.5 Fronius inverters are holding up?

        I wake up every morning and think I'm glad to see another day. My eleven year old Fronius transformer inverters must think the same thing........well maybe if they were AI.

        Comment

        • bcroe
          Solar Fanatic
          • Jan 2012
          • 5203

          The pair of Fronius IG 7.5 are just doing their thing after 10 years.
          The new-out-of-the-box spare is mounted next to them, just need
          to move 2 wires and throw a breaker if backup is needed. Guess
          it might be a good idea to actually try that some day, might take
          commissioning to get it going. No more worries about high line
          voltage programming since the heavy feed was installed in 2020.

          Looking good so far this year, the 15KW inverter plant delivered
          150KWh today. The previous year was rather poor sun, generation
          was a bit under 28,000 KWh. I got to keep more of that, the 2020
          heavy feed is delivering close to an extra 1000KWh of generation
          to the meter for credit. I made it past 1 April reset with a 1700 KWh
          in the black surplus (given to the PoCo). Most stuff here just ran,
          one of the 6 heat pumps needs attention.

          Some energy ideas, new mounts could boost output and reduce snow
          accumulation. And more house insulation, windows and in attic.
          Observation of loads is ongoing, but Energy Star and some mods
          have brought efficiency to a high level. Design a clipping level monitor.

          However most attention today is catch up on stuff ignored for the
          first PV decade. Need to get a new antenna up before the old one
          falls down, still considering J.P.M.s advice how to (not) do that on
          the steel roof. Some really big chunks of snow slid down this winter,
          I am building some clamp on slide restrictors using the same 6061
          aluminum and 18-8 SS bolts that have worked so well holding panels.
          Bruce Roe

          Comment

          • DanS26
            Solar Fanatic
            • Dec 2011
            • 976

            I recently added an antenna to my mid-1800's barn with a very slick metal roof.........

            IMG-0756.jpg

            Comment

            • bcroe
              Solar Fanatic
              • Jan 2012
              • 5203

              Here I am again, smoke from wild fires in the NW is sending haze over
              the IL area again. While not terribly severe, it is enough to cause the
              inverters to drop out of clipping (about 7600W each), to more like 7300
              or 7400W. Bruce Roe

              Comment

              • bcroe
                Solar Fanatic
                • Jan 2012
                • 5203

                After a decade the 15KW system here has again developed
                wiring problems. The twin 7.5KW inverters normally are a
                match to around 1%, but lately EAST was lagging some. A
                quick check with the clamp on DC ammeter indicated all
                strings were close to a match. More checking, after half a
                day running full power (that is up to 8 hours with this
                configuration) the EAST DC disconnect box was getting pretty
                warm.

                As usual I set up a night work light and waited for the darkness.
                Inside the Square D 361 box a 6 gauge wire looked like it
                was cooking its insulation. The 361 is rated 30A against
                the 22 I run, and 600VDC against my 400, 3 contact positions.
                Something about the plus array wire was making poor contact
                and getting ready to burn out. It was not my wire clamp screw.

                I had this same failure on another contact years ago, I had
                just moved the wires to the spare position. Something was
                not making good contact, not sure if it was the bolts holding
                metal together, or the switch contact. Is there a contact lube
                that should be used on these?

                Fortunately I have a lot of spare parts, and these boxes are
                designed so a few screws from the open door side allow
                replacing whole units. I found a nice switch section, made
                sure all its screws were pretty tight, and soon had it installed.
                Hand test today indicated proper cool operation.

                There are plenty of the 361 outdoor boxes on Evil Bay, some
                with 600V fuses (that I do not need), and some with just a
                switch. Bruce Roe PVburnedDC.jpg

                Comment

                • Mike 134
                  Solar Fanatic
                  • Jan 2022
                  • 393

                  Originally posted by bcroe
                  After a decade the 15KW system here has again developed
                  wiring problems. The twin 7.5KW inverters normally are a
                  match to around 1%, but lately EAST was lagging some. A
                  quick check with the clamp on DC ammeter indicated all
                  strings were close to a match. More checking, after half a
                  day running full power (that is up to 8 hours with this
                  configuration) the EAST DC disconnect box was getting pretty
                  warm.

                  As usual I set up a night work light and waited for the darkness.
                  Inside the Square D 361 box a 6 gauge wire looked like it
                  was cooking its insulation. The 361 is rated 30A against
                  the 22 I run, and 600VDC against my 400, 3 contact positions.
                  Something about the plus array wire was making poor contact
                  and getting ready to burn out. It was not my wire clamp screw.

                  I had this same failure on another contact years ago, I had
                  just moved the wires to the spare position. Something was
                  not making good contact, not sure if it was the bolts holding
                  metal together, or the switch contact. Is there a contact lube
                  that should be used on these?

                  Fortunately I have a lot of spare parts, and these boxes are
                  designed so a few screws from the open door side allow
                  replacing whole units. I found a nice switch section, made
                  sure all its screws were pretty tight, and soon had it installed.
                  Hand test today indicated proper cool operation.

                  There are plenty of the 361 outdoor boxes on Evil Bay, some
                  with 600V fuses (that I do not need), and some with just a
                  switch. Bruce Roe PVburnedDC.jpg
                  Is that brownish color light rust on the rivets? Perhaps some condensation over the past 10 years leading to the poor connection.

                  Comment

                  • DanS26
                    Solar Fanatic
                    • Dec 2011
                    • 976

                    Bruce, I use silver conductive grease on every connection and a torque screwdriver or wrench. Not to be confused with dielectric grease. It’s expensive but we’ll worth it IMO. Use very sparingly as excess will short a circuit. If + and - are near each other.

                    Never had a connection failure in my system.

                    Comment

                    • bcroe
                      Solar Fanatic
                      • Jan 2012
                      • 5203

                      Originally posted by DanS26
                      Bruce, I use silver conductive grease on every connection and a torque screwdriver or wrench. Not to be confused with dielectric grease. It’s expensive but we’ll worth it IMO. Use very sparingly as excess will short a circuit. If + and - are near each other.
                      Never had a connection failure in my system.
                      I am again bringing the main PV wiring into a more regular review,
                      even using a temp gauge to check for a box heating up after a
                      few hours at max power. I will be using some kind of terminal
                      protection on everything now. And spare shutdown assemblies
                      are prepared and sealed, just in case. The post mortum hints to
                      me, the issue has been the aluminum terminal block that came
                      bolted to the DC shutdown switch assembly. I am replacing all
                      of these with copper terminal blocks + anti corrosion stuff.

                      This year the big solar item is the smoke. Usually not so common
                      here in nothern IL. Even smoke not looking so thick, has a big
                      impact on solar energy. I am used to seeing the 15KW system
                      peaked out for nearly 8 hours a day many times. But recently it
                      has trouble getting up to the full 15KW capacity. Even when the
                      sky is not cloudy, production might be down 20% or more. Still
                      the array is fighting it, energy reserve is about 7.8MWh vs 8MWh
                      best at this date.

                      Then there is air quality, worst numbers I have ever seen. But
                      smoke containts physical particulate, which my electronic air filter
                      can remove no matter how small. The furnace blower operates it
                      around 20 minutes every hour. This really works, even before the
                      smoke, I could see that the dust particles in a beam of sun were
                      way down. The overall PV system produces enough energy to
                      allow this luxury (?) at no extra cost beyond cleaning the filter.
                      The blower motor (a standardized direct drive) was recently
                      replaced as the original was about to fail. All motor wires were
                      the same, though I did need to touch up the impeller balance.

                      Bruce Roe

                      Comment

                      • PNPmacnab
                        Solar Fanatic
                        • Nov 2016
                        • 425

                        Originally posted by bcroe

                        Once again Nyle announced the e8 water heating heat pump adapter,
                        might soon be available. It is still in the process of being Energy Star
                        certified, UEF tested, UL tested, and other things. If I ever get one,
                        the energy reserve might be exhausted, better than giving it away.

                        IMGP2436.jpg
                        A friend of mine just got a e8 end of May and finally got around to installing it. He is quite impressed. He got build #4, just after the ones sent off for regulatory testing. So, I guess that is still experimental as it has no certification. Surprised it is a 120V unit with the market being primarily commercial. He uses it in singe pass full temperature output.

                        Comment

                        • bcroe
                          Solar Fanatic
                          • Jan 2012
                          • 5203

                          This has been a year of very little rain, but local farmers managed to
                          get an average corn crop anyway. There were a lot of clouds that
                          did not produce any rain, just hurt solar. As of 1 Nov NetMetering
                          winter reserve matched my past best, 14,000 kWh. Usually it then
                          starts to reduce, but record warm weather and a few more sunny
                          days have it still holding 13 Nov. With any luck there will be plenty
                          of kWh thru this winter. Equipment has been doing well since the
                          switch repair.

                          Bruce Roe

                          Comment

                          • Rade
                            Solar Fanatic
                            • Aug 2023
                            • 106

                            Question: What is a "POCO"? It's not an acronym I am familiar with.
                            Rade Radosevich-Slay
                            Tiverton, RI

                            Comment

                            • Ampster
                              Solar Fanatic
                              • Jun 2017
                              • 3650

                              Originally posted by Rade
                              Question: What is a "POCO"? It's not an acronym I am familiar with.
                              POCO is Power Company.
                              9 kW solar, 42kWh LFP storage. EV owner since 2012

                              Comment

                              • Rade
                                Solar Fanatic
                                • Aug 2023
                                • 106

                                Originally posted by Ampster

                                POCO is Power Company.
                                Merci!
                                Rade Radosevich-Slay
                                Tiverton, RI

                                Comment

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