Solar Water Pump

[DeereHunter]

Hi, does anyone have a good idea regarding pumping water for livestock in remote locations? I'm been reading about solar powered pumps and this idea seems pretty good. Does anyone out there have any useful info on this subject.
Think Spring.....Shawn

[Pat]

Shawn, I recommend "Home Power" magazine. They have had many writeups about off grid solar water pumping. Water pumping is a good match to solar since for stock watering and irrigation yo don't have to have a lot of pressure, just flow, and it is OK to only pump when the sun shines.

You need to size your systems water storage (pond, tank, trough, whatever) to hold enough water to get by during the longest reasonably expected period of heavy overcast weather in the worst season you want water pumped.

You need to size the solar array and pump so that it will pump enough water for your needs. The good news is that you don't need a battery in this application. There are advertisers in "home Power" who would be happy to recommend system components to you .

You need to supply them with good input info. How deep is your well (worst case distance from highest point you want to lift the water to the surface of the water in the well at its lowest. How many gallons per week do you need? Gallons per day? This is not the same info! If you have a large enough container you can pump water when the sun is plentiful and last through long dark spells using a smaller pump. If you have a small container (trough) then you need to be able to refill it under less than optimum solar conditions which increases the size of your PV array by so much that you will faint when you see the cost figures.

I assume you want to design the most economical system capable of meeting your requirements. I suggest that a larger water storage capability will save you significant $ in solar cells (PV) and in the size of the pump you need. A small pump running most days to wharehouse water is cheaper than a larger pump to do the job quicker when needed.

Solar pumping can be quite practical in off-grid applications and is used in several third world countries for irrigation and drinking water.

[img]/forums/images/icons/smile.gif[/img] Pat [img]/forums/images/icons/smile.gif[/img]

[egon]

There is another type of tried and tested solar water pump which is quite capable of running in the dark without need for direct sunlight. They come in various shapes and forms depending on country of origin and water supply.

The ones we are most familiar with are called windmills. You may have seen one being destroyed in a truck commercial a few years ago.

Almost every farm used to have one. Many were located in remote locations for stock tanks.

These have their place but if you live in an area without proper wind supply the solar collector may be better.

Egon

[Pat]

Egon, When reading your first paragraph, I thought the punchline was going to be "CLOUDS and RAIN." Windmills are going away. I for one miss them. Call me sentimental but I like them. They are getting (already are) quite scarce hereabouts where they used to be very plentiful.

I haven't verified all of this but it sounds reasonable: I heard comments that with the advent of deep wells and large irrigation systems, some aquafers have been lowered such that many windmills, or the wells they were installed on, are no longer usable.

Pat

[egon]

Pat:

The largest aquifier in the US, The Agulla, has been depleted to the point it is no longer economical to pump water for irrigation.

Egon

[Pat]

Egon, There are many regional aquifers that are in deficit mode and get lower every year with a crisis coming, delayed but coming. The huge circular irrigation units with their deep wells that make the large green bull's eyes visible from space need to have wells that are deeper and deeper as they deplete a NON-renewable (at the rate used) resource.

In our area there are some sections (640 ac, i.e. a square mile) where no one has found good water. Wells around here can just go bad and do all too often, as a delayed result of exploitive oil field practices. Salt water is pumped back into certain wells, sometimes poluting aquifers. Not too long ago an oil outfit was pumping their salt water (comes up with the oil sometimes) into a farm pond where it could overflow into a creek and then into the south Canadian river. They eventually got caught and did a half vast (alternate spelling) cleanup but left behind salt poluted barren patches of erroding land.

If there is water to be pumped, which we must assume, then it would be easy to "run the numbers" and select between wind mill and solar. I think the economics would probbly favor solar as the well depth significantly increased.

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[egon]

Pat:

Good old salt water. It's a very consitent byproduct of oil production. Many resevoirs have salt water drive and many of the connate resevoirs contain salt water. Ideally it should be reinjected into formation to maintain the resevoir voidage/ pressure. In some/many cases fresh water is injected into resevoirs to maintain voidage/pressure. There are many different senarios here on production techniques but there irrelevant here. A salt water spill is many more times harmfull to the soil than a crude oil spill.

And yes, as depth increases the pump rod weight would make downhole electric pumps more efficient despite electrical line resistance losses. Maybe so even with shallower wells. But the same principle of solar cells versus wind power generated power source could still be debated.

I too like the windmill scenario. Somehow it seems to indicate simpicity, stability or consistency or maybe a way of life or something ???.

Egon

[GareyD]

Do you have any running water...if so, think about a ram pump...easy to build out of common pipe fittings, and run practically forever.

GareyD

[Pat]

Egon, I miss them too. In some instances, windmills are not a good answer compared to solar pumping. I'm nostalgic about the concept of hand cranked cars too but not interested in replacing my starter motor with a crank handle.

I appreciate much of the "old" technology but an not one to try to revert to it when there are better solutions. Not implying new and high tech is always better. I try to be a pragmatist and select the "best" solution dependent on the extant conditions.

Solar pumping is not a new untested technology, just not in everyones experience.

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