Vintage Windmill and Wind Generator Forum

I am on a rain delay out on the CO plains. This is an area of poor water quality. Drop pipe and rod really suffer. Even all brass 442 cylinders get barnacles on them. This pipe was still holding water but the couplers couldn't be broken so everything was cut to remove. A grinder had to be used to clean off the pipe OD to get elevators on


Solar pumps placed on pvc pipe and ss couplers make perfect sense. In 50 years, solar will have the same anesthetics as windmills....

Ron Stauffer
Montrose CO

I suppose time will tell, I have noticed most of the guys here who tried solar for stock wells have mostly given up and dropped a house pump down the hole and make the rounds with a Harbor Freight generator on the pickup to pump the tanks full.

I had 3 wells running Grundfos solar sq-flex pumps. They’d last for about 2-1/2 years, then go out (just out of warranty). The things are $2500 each, plus were another $500 to have the well guy pull the old one and replace (done with 20’ PVC sticks, 80’ to 160’ depth).

I recently had 2 go out at once. I had the well guy pull the deep one, and when he asked me if I wanted him to replace it, I told him I wanted to try something different. I replaced it, and the shallow one, with el-cheapo eBay Chinese solar pumps ($300, complete with control box and extra screw impeller), and 1” black poly pipe.

They’ll pump 4-5 gpm on the top-end (you can adjust the rpm with the control box), down to 1/2-1 gpm at the slowest. I’ve got one on a low-producing well (only about 2 gpm max) turned down to a little over 1 gpm, just to keep it from sucking a bunch of silt or cycling on/off, constantly.

I know! I hate to use the Chinese stuff as much as anyone, but the Grundfos is made in Mexico (and Lorentz are from somewhere in Asia). The two I did are doing ok, after a year, and I’ve even put another one on a 60’ well (on another place) that had an old Dempster mill on it years ago (it blew over 10-15 years before I bought the place).

I wish I had a windmill on every well (I’ve got 6 wells, total), but it’d cost me $10k-$15k, each, to put a windmill on each one.

I am NOT trying to say these pumps are as good as Grundfos. What I WILL say is that they are 1/10th the price of a Grundfos, and they are VERY easy to pull by hand on a shallow well (the 160’ one is almost a 2-man job). If I can get 1-1/2 to 2 years out of them, I will be money WAY ahead, vs. the Grundfos, so I’m giving it a shot.

Used solar panels can be purchased from SanTan Solar, and the combined price of panels/pump/tubing/wire was about $1000-$1200…

Just a thought for guys who are thinking of a solar setup on a shallow well, and might not be excited about throwing $3k plus at a Grundfos…

We have had customers throw out all their mills, and convert to solar, and then we have had customer throw out all their solar and go back to windmills. Conditions on the farm vary greatly from person to person, but the determining factor for most is cattle load. The more cattle, the more water of course. The wind issue comes around in July and August when it usually stops blowing for a few weeks.
There is no perfect system. However, we have installed many windmill wells with a cheap 110 volt submersible, and that works reliably with wind or no wind. Or both at the same time. Most farmers have generators on their trucks anyway.

To be up front, we have used nothing but grundfos pumps for over 10 years and have not replaced any from failure. I left on this work trip with 7 on the truck so it isn't like I have no experience with them.

Panels are not all the same. Pumps are not all the same. Installers are not all the same.

All are solar installs are custom sized with the best quality panels, appropriate grundfos pump and calculations are done for wire size and keeping within grundfos recommedations for voltage drop.

If your installer doesn't know the difference between Vov and Vmp, max current and voltage tange for a sqf pump and acceptable voltage drop % off the top of his heD, I think the issue is with your installer. If your installer relies on his pump supplier for this info, that can be equally as bad.

If you are paying someone to service those shallow wells with Chinese positive displacement diaphragm pumps, that will get old too.

I guess where I am at is that you shouldn't lump windmill category with Aermotor & American West/WindEngine, import and galvanized pipe etc. And you shouldn't lump solar with good and low quality panels, grundfos & other pumps etc

Ron Stauffer
Montrose CO

HELP , my head just exploded trying to decifer what you said Ron !!! I an NOT a solar installer , just bearly a windmill guy so no help here .

What ever happened to the good old days, things were less complicated and lasted forever!! And you could work on them with a hammer and wrench!!!!

Ron Stauffer wrote: Sat May 20, 2023 6:31 pm To be up front, we have used nothing but grundfos pumps for over 10 years and have not replaced any from failure. I left on this work trip with 7 on the truck so it isn't like I have no experience with them.

Panels are not all the same. Pumps are not all the same. Installers are not all the same.

All are solar installs are custom sized with the best quality panels, appropriate grundfos pump and calculations are done for wire size and keeping within grundfos recommedations for voltage drop.

If your installer doesn't know the difference between Vov and Vmp, max current and voltage tange for a sqf pump and acceptable voltage drop % off the top of his heD, I think the issue is with your installer. If your installer relies on his pump supplier for this info, that can be equally as bad.

If you are paying someone to service those shallow wells with Chinese positive displacement diaphragm pumps, that will get old too.

I guess where I am at is that you shouldn't lump windmill category with Aermotor & American West/WindEngine, import and galvanized pipe etc. And you shouldn't lump solar with good and low quality panels, grundfos & other pumps etc

Ron Stauffer
Montrose CO

Not arguing with anything you said. Will mention that pumps (11-sqf-2) were run with Kameka panels x 2 (60 w, 48v)(I’ve subsequently switched to higher wattage/lower voltage used panels for the Chinese pumps), in series, using good quality 12 ga wire (deepest had 160 ft of wire). He grounded the panel frames to earth (in case of lightning strike), and pumps were at least 10 ft off bottom (so not in dirt, but even with this, wells in this area produce LOTS of red dirt sediment). I know that the Grundfos can run on a large range of voltage (30-300), and even have the technology to run on AC or DC, so wasn’t aware they were very “picky” about voltage/wattage input.

Wish I knew if, (and if so, what) he might have been doing wrong, and this was multiple pumps on multiple well sites, so don’t feel like I just got one “fluke” bad one.

As for the cheapies I’m trying on my own, they are NOT diaphragm pumps. These are helical/screw pumps, like the Grundfos. And again, I’m in no way trying to say they’re “as good as” or “better” than Grundfos, but I simply can’t justify $2500 pumps with $500 service fees to drop them, that only last me a little over 2 years, when a $300 alternative MAY exist (that hopefully lasts the same 2 years, time will tell).

I know an optional “control box” is available for the Grundfos, but does that box do much more than offer diagnostics?? (My installer did not use these $500-$600 boxes). I know that all the other functions of the Grundfos (including dry run protection) are built into the pumps, themselves, and as long as you’re supplying power within their operating range, with wiring that’s of sufficient gauge/quality to not cause resistance issues, I’m not sure what there would be to mess up?? Could these things simply be “eating themselves alive” with sediment?? (PM me, and I’d be happy to tell you the name of my well guy and my location)

(Not trying to hijack anything, just seriously interested. If I could get 6/8/10 years out of the Grundfos, I’d be happy to just pay the money and move along!)

We have always used the cu 200 controller on all our installs. There has to be a certain amount of sun before it will try to pump.

Grundfos uses the same motor on all the sqf series. We use a lot of 11 & 6. It is the Vmp rating you use for the specified voltage, never exceeding 8.5A and wire sized for max 2% voltage drop

Some time research Tier 1 solar panel manufacturers. It is no guarantee but it is a start. We use the same panels as we do for off grid homes. I like 72 cell panels for higher voltage and buy in pallet quantities..

I did my first off grid system 28 years ago. Systems were 12 & 24 volt nominal systems so voltage drop always had to be considered and calculated.

Ron Stauffer

I am back from a very extended work trip and have some time to research on your issues.

1 Is it the pump end or motor that went out? As I said earlier, Gf uses the same motor on all their sqf series and just the pump end is varied for application. Gf does not sell pump ends and motors separate.

2 I had never heard of your panels so had to check specs. They are amorphous. For a very short time, Gf had offered amorphous panel packages with their pumps. This was only for a short time and never really heard why they were discontinued. We only use monocrystalline panels with most applications using 400-800 watts.

3 The Vmp rating is high for amorphous panels so voltage drop should not have been an issue. Here is the chart to calculate voltage drop. Gf wants you to use 8.5 Amp in the calculation whether available or not. Vmp rating on the panel is what is used in calculating and if in series it is Vmp times the number of panels.

Most of our installs are 2 mono panels 750-800 watts with a combined Vmp of 80. #12 wire works to 100' and #10 >100' and <200'




4 The motor end of the sqf is a half hp motor accepting both DC and AC. A half hp motor draws roughly 1050 watts. On DC, the motor just spins slower or faster based on the power (watts) that is feeding it. I am guessing that two Kaneka 60W panels would be starving that motor?
Gf does have tech support for licensed installers.

Gf does have a model Mini 5-8 designed for <100' head. It is about $500 less than the others. We have success with these also feeding them with one 350-400 w panel.

Hope this helps

Ron Stauffer
Montrose CO