Solar irrigation system

SystemSystem Posts: 2,511 admin
I am in the beginning stages of putting together a small irrigation system with a PV array and dc solar pump. I have tapped into a pond with a horizontal 15 inch x 15 foot pipe set into a perpendicular 24 inch pipe. The water depth is 8 feet below the surface on my property. The total height the water will be pumped is 48 feet and the total distance will be approximately 200 feet. I was planning on using a 75 gallon pressure tank set a 45 PSI to run the sprinklers.

My first thought was to put the pressure tank at the top of the hill. However, it would be much easier to install it near the pump. The 40 feet of head (from where the tank would sit) would be about 20 psi. I was wondering if there would be any negatives to installing the pressure tank down the hill and pressuring it to 65 PSI instead of putting it up the hill?

The next question I have is how to pick a solar panel. I plan on using a 24 V system with the conenergy 3020 solar piston pump. By looking at the chart it looks like I need 269 Volts + 20%. I figure two 24 V 170 watt panels would do it. What should I be looking for when I try and decide on a manufacturer? There seem to be a large number to choose from.

Thank you

Comments

  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Solar irrigation system

    One question,,,,and I ask this knowing little if anything about irrigation, but why are you going with pressurized sprinklers rather than drip/soaker irrigation? It seems that the advantages of drip irrigation are, reduced pressures, better water efficiency, possibly better electrical efficiency.

    My intuition is that it would be easier to pump the P-tank and push the water up the hill rather than pump the water up the hill into the tank. I suspect that some engineer can give some thoughts on friction losses etc. I would suggest going withe the biggest up hill line you can deal with, but 48' of elevation and 200' of horizontal will put some movement stresses on the pipe, so consider some proper thrust block design to limit movement, or allow for that movement some other way.

    Icarus
  • System2System2 Posts: 6,290 admin
    Re: Solar irrigation system

    The idea of using a pressurized system was so that I could tie into the existing substantial irrigation system I already have on the property that is currently using metered water. However, after looking at this more, I have come to the conclusion I either need to get power down to the well and go with a larger electric pump or go with the solar and a different irrigation system. The 5 gpm put out by the conergy pump is not going to cut it with the system I have. I will need more like 20 gpm at 45 psi.

    It will probably be more cost effective to run the power....
  • Lefty WrightLefty Wright Solar Expert Posts: 111 ✭✭
    Re: Solar irrigation system

    You mentioned pumping the pressure tank up to 65psi in one plan and 45psi in another.

    Just an observation; I pump my tank up to 55psi. It takes only a couple of minutes for my booster pump to get the tank to 45psi and a lot longer to get from 45 to 55psi.

    Depending on the capacity of your pump, this may be a consideration.
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