Durability and value of solar pumps vs efficient pumps?

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  • OregonSolar
    Member
    • Oct 2013
    • 56

    #16
    Originally posted by Texas Wellman
    Absolutely not, you're dead wrong. I would actually say that very few solar pumps are diaphragm pumps, although there are many that are positive displacement (helical pumps).

    Almost all domestic pumps are centrifugal and can easily make enough pressure for whatever you need, even if your water level is 1,000 ft. The reason a lot of solar pumps are not centrifugal pumps are because they don't have enough power to spin at a high enough rate for the centrifugal pump to be able to work. Positive displacement pumps do not need to spin very fast to work so they are used a lot in solar applications.
    Exactly, on the solar pumps. I don't really know that much about regular domestic pumps, just that they aren't designed like a regular centrifugal pump. Just that a solar centrifugal pump would require a massive amount of panels to get that much power.

    Oh, and an advantage of diaphragm pumps? They are better at low power, like say a cloudy day. They'll pump less water, but still enough to effectively do something. As far as I know, most of the other pumps have a pretty fast drop off from the power.

    And when you say positive displacement pump, you mean one like a rotary vain or lobe, right? Just clarifying.
    [url]http://getcraft.net/?ref=Bm5Om0rne[/url]

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    • Texas Wellman
      Member
      • Apr 2013
      • 54

      #17
      Diaphragm pumps are PD as are helical rotor.

      You are confused. High head is relative. To me high head is anywhere over about 300'. For somebody in the mountains it could be 500-600'. Head includes the pressure at the top so if you need about 50 psig in your system you need to add about 115' to the overall head in addition to the vertical height the water needs to be pumped.

      Solar centrifugal pumps don't require "massive" amount of solar power, just an adequate amount. The "centrifugal" solar pumps that I Have installed run on one single 180-watt panel and make about 12 GPM on about 20-30 ft of head.

      The PD pumps work well if you want to run on lower power (less panels). If you need a large quantity of water there is no question that centrifugal is the way to go. The centrifugal solar pumps are exactly like their domestic counterparts. In fact the Grundfos pumps are identical to the ones used for AC pumps.

      Originally posted by OregonSolar
      Exactly, on the solar pumps. I don't really know that much about regular domestic pumps, just that they aren't designed like a regular centrifugal pump. Just that a solar centrifugal pump would require a massive amount of panels to get that much power.

      Oh, and an advantage of diaphragm pumps? They are better at low power, like say a cloudy day. They'll pump less water, but still enough to effectively do something. As far as I know, most of the other pumps have a pretty fast drop off from the power.

      And when you say positive displacement pump, you mean one like a rotary vain or lobe, right? Just clarifying.

      Comment

      • OregonSolar
        Member
        • Oct 2013
        • 56

        #18
        Originally posted by Texas Wellman
        Diaphragm pumps are PD as are helical rotor.

        You are confused. High head is relative. To me high head is anywhere over about 300'. For somebody in the mountains it could be 500-600'. Head includes the pressure at the top so if you need about 50 psig in your system you need to add about 115' to the overall head in addition to the vertical height the water needs to be pumped.

        Solar centrifugal pumps don't require "massive" amount of solar power, just an adequate amount. The "centrifugal" solar pumps that I Have installed run on one single 180-watt panel and make about 12 GPM on about 20-30 ft of head.

        The PD pumps work well if you want to run on lower power (less panels). If you need a large quantity of water there is no question that centrifugal is the way to go. The centrifugal solar pumps are exactly like their domestic counterparts. In fact the Grundfos pumps are identical to the ones used for AC pumps.
        In, say a stock watering situation like I have multiple setups, on-demand water is less a priority than just producing enough per day. So I run a 2GPM diaphragm pump that give enough water for 40 cows from 6hrs of sun on 2 80 watt panels.

        20-30 ft of head is NOT going to happen in most areas. In fact, my local well codes require at least 50Ft of casing to prevent runoff contamination of groundwater.

        Of course, here in volcanic Eastern Oregon, you might have lucky people with artesian wells that flow at 100GPM and 2Psi without any effort at all. But that is a rare minority.
        [url]http://getcraft.net/?ref=Bm5Om0rne[/url]

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        • inetdog
          Super Moderator
          • May 2012
          • 9909

          #19
          Originally posted by OregonSolar
          Of course, here in volcanic Eastern Oregon, you might have lucky people with artesian wells that flow at 100GPM and 2Psi without any effort at all. But that is a rare minority.
          As a series of beer commercials told us too many years ago, those artesians are very shy creatures and hard to find. They keep their wells well hidden too.
          SunnyBoy 3000 US, 18 BP Solar 175B panels.

          Comment

          • russ
            Solar Fanatic
            • Jul 2009
            • 10360

            #20
            Originally posted by OregonSolar
            Of course, here in volcanic Eastern Oregon, you might have lucky people with artesian wells that flow at 100GPM and 2Psi without any effort at all. But that is a rare minority.
            What part of Eastern OR? I grew up in Madras.
            [SIGPIC][/SIGPIC]

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            • Texas Wellman
              Member
              • Apr 2013
              • 54

              #21
              Actually the depth of the well really doesn't matter. For example, I have a well that is 480 ft deep but the pressure of the aquifer pushes the water up to about 40-50 ft of the surface. In another area I service the well depth is about 200 ft but the water only comes to about 120' from the surface. Most of the solar pumps I install are in 100' wells that have 10' water levels. All of my solar pumps are run open ended so there is no additional head. All of these wells are strong producers (100 gpm+) so drawdown is not a problem.

              I looked at the shurflo's but the price was just not cheap enough for what you're getting. I will say that I have dealt with sun pump and they were very good. I had a problem with my controller about 10 months after the install and they sent me a new one no questions asked. I highly recommend using them if they have a product that fits your needs.

              Originally posted by OregonSolar
              In, say a stock watering situation like I have multiple setups, on-demand water is less a priority than just producing enough per day. So I run a 2GPM diaphragm pump that give enough water for 40 cows from 6hrs of sun on 2 80 watt panels.

              20-30 ft of head is NOT going to happen in most areas. In fact, my local well codes require at least 50Ft of casing to prevent runoff contamination of groundwater.

              Of course, here in volcanic Eastern Oregon, you might have lucky people with artesian wells that flow at 100GPM and 2Psi without any effort at all. But that is a rare minority.

              Comment

              • OregonSolar
                Member
                • Oct 2013
                • 56

                #22
                Originally posted by russ
                What part of Eastern OR? I grew up in Madras.
                Well, not quite eastern oregon, I'm just slightly west and over the hill from Lakeview.
                [url]http://getcraft.net/?ref=Bm5Om0rne[/url]

                Comment

                • OregonSolar
                  Member
                  • Oct 2013
                  • 56

                  #23
                  Originally posted by Texas Wellman
                  Actually the depth of the well really doesn't matter. For example, I have a well that is 480 ft deep but the pressure of the aquifer pushes the water up to about 40-50 ft of the surface. In another area I service the well depth is about 200 ft but the water only comes to about 120' from the surface. Most of the solar pumps I install are in 100' wells that have 10' water levels. All of my solar pumps are run open ended so there is no additional head. All of these wells are strong producers (100 gpm+) so drawdown is not a problem.

                  I looked at the shurflo's but the price was just not cheap enough for what you're getting. I will say that I have dealt with sun pump and they were very good. I had a problem with my controller about 10 months after the install and they sent me a new one no questions asked. I highly recommend using them if they have a product that fits your needs.
                  100' deep with 10' static level? What universe are you in? Rarely, if ever, have I ever seen a well with that kind of characteristics that the driller didn't just go deeper for a little artesian. Probably the closest thing to that I've seen is a local well that was 65' deep with a static of 2'.
                  Last edited by russ; 10-24-2013, 10:41 PM. Reason: removed link
                  [url]http://getcraft.net/?ref=Bm5Om0rne[/url]

                  Comment

                  • Naptown
                    Solar Fanatic
                    • Feb 2011
                    • 6880

                    #24
                    Please remove the gaming link from your signature.
                    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]

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                    • russ
                      Solar Fanatic
                      • Jul 2009
                      • 10360

                      #25
                      Oregon - I removed the link for you - that is not allowed.
                      [SIGPIC][/SIGPIC]

                      Comment

                      • Texas Wellman
                        Member
                        • Apr 2013
                        • 54

                        #26
                        Uhh....I live in the same universe that you do I suppose. Here are some more things that happen in our universe:

                        People in the southern hemisphere point their solar panels due north, snow is rare in this part of Tx, and gasoline is $.12 in Venzeuela and Saudi Arabia. And also, did you know that old McDonald was a really bad speller?

                        Originally posted by OregonSolar
                        100' deep with 10' static level? What universe are you in? Rarely, if ever, have I ever seen a well with that kind of characteristics that the driller didn't just go deeper for a little artesian. Probably the closest thing to that I've seen is a local well that was 65' deep with a static of 2'.

                        Comment

                        • russ
                          Solar Fanatic
                          • Jul 2009
                          • 10360

                          #27
                          Originally posted by OregonSolar
                          100' deep with 10' static level? What universe are you in? Rarely, if ever, have I ever seen a well with that kind of characteristics that the driller didn't just go deeper for a little artesian. Probably the closest thing to that I've seen is a local well that was 65' deep with a static of 2'.
                          The depth of the well and static level are two totally different things. The amount of water over the pump can provide more pumping time if needed.

                          Most places an artesian well - open flowing is not possible.
                          [SIGPIC][/SIGPIC]

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