Getting Well Off Grid

Keith · #1 12/24/12, 10:11 PM

Several places this thread could go but will try here first.

I have a 300' well and the pump uses roughly 2200 watts.

It's an on-demand well with a pressure tank. It's at the top of a hill, real roughly 30' higher elevation from the home.

To move to solar I think I need to redo the whole setup. From reading I need a dual pump system, instead of the 2200 watt pump, I need to replace that with a much lighter duty pump that feeds a storage container, then an even smaller pump to push pressure to house through the pressure tank.

For those who have converted to solar based pumps, is that the setup you are using? What wattage are your pumps and how much solar wattage are you generating/storing?

Common Tator · #2 12/24/12, 10:22 PM

Or get a windmill.

http://dorothyainsworth.com/wind/windmills.html

texican · #3 12/24/12, 10:37 PM

With 30' of elevation, you'll have 15lbs of water pressure, if your tank is on the ground. If you can elevate the tank, your pressure will be even higher. Unless you have need of 'traditional' 40lb pressure, 15 will work. I've been on 10lbs for close to 20 years now (gravity flow system).

Phalynx · #4 12/24/12, 11:11 PM

I just went though this thought as well. Its not the 2200 watts that gets you, its the start up wattage which could be 3-5 times higher. There was a thread somewhere where someone installed a secondary pump in the shaft with the primary pump. It can run off of 12V-24V DC. It can be plumbed into the existing system and will provide much lower amounts of water but at normal pressures. This is likely where I will be going.

wy_white_wolf · #5 12/25/12, 09:50 AM

Texican has the right idea. You don't need the second pump if you can get the cistern mounted higher then the house.

Gary has quite a few links for solar water pumping.

http://www.builditsolar.com/Projects...terpumping.htm

tkrabec · #6 12/25/12, 11:08 AM

I've read about some solar pumps that basically just run when the sun is up, they use a linear voltage (or amperage i forget) to run the pump when there is sufficient light. it pumps slowly when the light is low, and at full speed when it is bright. The water goes to a holding container, then a secondary pump is used to pressurize or gravity flow.

Jim-mi · #7 12/25/12, 11:14 AM

Another way is to replace the existing well pump with a new 'soft start' pump . .it will greatly reduce the amount of electric needed...

That into a non pressurized large storage tank..

The pumps are not cheap . . . . but in the long run 'well' worth it.

At the bottom of the hill (house) very easy to add a small ' pressure booster' pump into a large bladder tank...............If the gravity does not give you the flow you think you gotta have..

The majority of the well/pump guys are not keeping up with the modern pumps available today.
Instead they still want to "sell" those tried and true old energy Hogs.......

Nottingham · #8 12/25/12, 02:27 PM

I'm working on designing/installing an off-grid solar well system on my farm right now. The solar racking will be made from 2" schedule 40 steel pipe that I bought from the scrapyard. The solar array will be 3 220 watt poly-crystalline PV panels. I bought 4 of these from a solar installer that was liquidating them due to not having enough of them for a full solar array for the retail cost of about 1 1/2 panels.
The big cost is the pump and controller. I'm looking at the Grundfos SQF pumps because you can run them off DC or AC. I'll be able to hook the pump up to my diesel generator if I need to run the pump when the solar is not running. I am going to pump into a big tank on the highest point on our farm which luckily is near our well.
Pros of the Grundfos SQF pump are; the pumps are repairable, made from stainless steel, run on 30 to 300 VDC or 90 to 240 VDC, can be run on solar, wind or from grid power, has a dry run safety switch.
The biggest con that I have found is the cost. The SQF pump and CU200 controller will cost me about $2200.
Because of the cost I am considering a DC only submersible pump for about 50% of the cost of a Grundfos pump. The drawback is not having the option to pump with AC grid or generator power and some of the built in safety features. Short term this would not be a problem since I will be pumping into a large tank but long term this would be an issue because I plan to run our future house off of the same well. I could install a battery bank to get around this problem. I need to make this decision this week but leaning more towards the Grundfos.
Mike