Solar Water Pumping for Cattle

[texastrooper]

I am planning a simple solar project for supplying water to my cattle. The well is 40' deep. It is not a very strong well and will pump off quickly. Because of this I am planning on purchasing a Grundfos 5SQ05-90-115v .5 HP pump. It has run dry protection and requires no controller. It also has soft start which does not have the electrical surge when starting. The pump is 4.2 amps. I have a 100w solar panel and 2 35 ah batteries. I also have a 2000w inverter. I plan on using a pressure switch and pumping into a pressure tank. The water will flow into a trough for cattle. I estimate pumping about 75 to 100 gallons per day. This will be my first project. Will this work? What more information do you need to help? Anyone have any better ideas? AC is not an option. Thank you for any help.

[green]

Let me start by saying I am not an expert, there are others here that can help you much better than I. But I just wanted to state that an off grid application needs to be balanced and capable of replacing the energy that is used each day. Some simple math will tell you that your pump will run at about 500 Watts. How long do you plan to run it each day? Say its 3 hours a day, that's 1500 Watt Hours. Do you think your 100 Watt panel will produce that much plus accounting for losses? The answer is no. The math is simple but even I who have been reading and learning for a while now struggle a bit when it comes to losses and location and designing for worst case. So I will let the others here that can do it in their sleep help you get a balanced system.

I only chimed in because I am currently working on a solar powered water pumping system right now for my rain water capturing system. Very small 12V .5A pump and just a 12V 12AH battery. 60W homemade panels supplying the power. So far so good, only set up for a couple weeks now though.

Good Luck

[Texas Wellman]

Why did you not opt for the SQ Flex instead? It's solar ready.

I am planning a simple solar project for supplying water to my cattle. The well is 40' deep. It is not a very strong well and will pump off quickly. Because of this I am planning on purchasing a Grundfos 5SQ05-90-115v .5 HP pump. It has run dry protection and requires no controller. It also has soft start which does not have the electrical surge when starting. The pump is 4.2 amps. I have a 100w solar panel and 2 35 ah batteries. I also have a 2000w inverter. I plan on using a pressure switch and pumping into a pressure tank. The water will flow into a trough for cattle. I estimate pumping about 75 to 100 gallons per day. This will be my first project. Will this work? What more information do you need to help? Anyone have any better ideas? AC is not an option. Thank you for any help.

[Sunking]

OK I am not going to explain all the details and math behind it because there are hundreds of threads with details, and a Sticky telling you all the details. All I am going to tell you is what is needed based on:

Grundfos SQ Series 3" Stainless Steel Submersible Pump, 5 GPM, 1/2 HP, 115V, 2 Wire.
100 Hundred gallons per day
System in Central Texas
40 feet depth.

Requiremnts:

Motor Power = 490 watts
GPM = 4
Hours to pump 100 Gallons = .5 hours
Power consumed = 250 watt hours
Winter Sun Hours = 3.5

Panel wattage required = [250 wh x 2] / 3.5 Sun Hours = 140 watts. Must use Battery panel with a Vmp of 16 to 18 volts
PWM Controller = 10 amps
12 volt AGM Battery = 100 AH. Must use AGM in this application to drive inverter with 45 amps with 100 AH battery.
Inverter minimum = 1 Kva

You were close but missed the battery by a lot. Do not put batteries in parallel. Use a single AGM 12 volt 100 AH minimum.

Alternative system at about the same cost or lower but superior performance. The battery might last 4 or 5 years. Use a cheap and undersized battery 1 year or less.

GTI Panel = 100 Watts. Grid Tied panels are much less expensive than Battery panels
MPPT Controller = 10 amps minimum. Morningstar Sun Saver MPPT 15 amp
12 volt AGM = 100 AH. Concorde Sun Saver PVX-1040
Inverter = 1 Kva

Have a nice day.

[Texas Wellman]

You don't need a pressure tank or batteries, you can pump directly into a trough. You can use a float to turn the pump on/off. If running a grundfos flex pump you will need at least 60V DC to the pump and it really likes about 90V. It will run on 30-300V DC.

The grundfos will also run on a generator and no special interface is needed but you do need one so that you can switch from solar to generator easily. I have installed several systems like this that will pump 3,000 gallons per day during the winter and more during the winter.

My advice is to not buy the Grundfos SQ and instead go with an SQ Flex and add one or two more 180W panels, which should cost you about $200 each. The SQ Flex will cost you about $2,000 for the pump on-line. Ditch the pressure set-up and run off of a float switch. Get a triple panel mount also, there is a place near Pampa that makes them and they are very sturdy and reasonable on price. You will need a 3" pole for 2 panels and 4" pole (10' length) for a 3-panel system.

I'm not sure how the mis-matched panels will perform, what is the voltage of your 100W panel?

Good luck.

I am planning a simple solar project for supplying water to my cattle. The well is 40' deep. It is not a very strong well and will pump off quickly. Because of this I am planning on purchasing a Grundfos 5SQ05-90-115v .5 HP pump. It has run dry protection and requires no controller. It also has soft start which does not have the electrical surge when starting. The pump is 4.2 amps. I have a 100w solar panel and 2 35 ah batteries. I also have a 2000w inverter. I plan on using a pressure switch and pumping into a pressure tank. The water will flow into a trough for cattle. I estimate pumping about 75 to 100 gallons per day. This will be my first project. Will this work? What more information do you need to help? Anyone have any better ideas? AC is not an option. Thank you for any help.