by Douglas Bullock
When my brothers and I got our place on Orcas Island, at the north end of Puget Sound, our idea was, 'Yeah, a solar water supply.' We had dry, sunny summers with little wind, a south and west facing hillside, and a wetland that offered virtually unlimited water at the bottom of the hill. It seemed like a perfect match. Well, in those days money was scarce and there were a lot of projects to nickle and dime it away. Setting up a solar pump was going to cut into both time and money. But back then, we wanted water now! Gardens, nursery and fruit trees were why we bought land in a first place, and they needed irrigation: summers in the San Juan Islands are dry.
After some ethical deliberation, we settled for the first decent, cheap pump we could find - a screaming, smoky two-cycle for $180.00, and used an old Dough-Boy pool for a holding tank. That got us started. After a couple of years we moved up to a larger four-cycle engine and a big heavy-duty pump. We were never happy with our setup though, and were always thinking, 'some day we'll do it right.' But what would it take to build the perfect, permacultural water-supply? A parabolic reflector with a Sterling engine or a steam-powered jack-pump? Or photovoltaic panels with electric motor and high-tech pump? Or the age-old boom and tripod system? The green options were many.
When the Dankoff 'Solar Forc' piston pump began showing up in ads (a light weight, low-power solar pump that could take a lot of dirt and dry running) we looked at their literature, hemmed and hawed, and said, 'That would sure be nice.' A year or two later I happened to see a photo of one in some literature. And that's when it clicked: 'Why, that's a low-volume horizontal-piston pump for ponds and shallow wells. That will work in our bog!'
I realized we could build a setup similar to the expensive Dankoff system for far less money. The technology of horizontal-piston pumps (other than the addition of photovoltaic power) hasn't changed much in almost 100 years. They've been a staple at farms and ranches, and I have seen quite a few sitting around unused or dumped. One wouldn't be hard to come up with. And I found myself thinking, 'I'll bet a surplus DC motor and some used solar panels wouldn't cost much . . .' Soon we had not one but a collection of these pumps. Most looked in pretty bad shape (we could gut those for parts) but a couple seemed okay. We had many old brands in our stash: Dempster, Homart, Eveready, Barnes, and more. The older ones are my favorites, because they date from the days when the art was as important as function.
The people who designed and built them were craftsmen, not simply linear-thinking engineer droids fresh out of a university. One of my favorites from our pile of pumps is Flash Gordon-esque and looks ready for launch. Another is Art Deco, and a third looks like a sturdy tractor from about 1940. Upon cleanup and inspection, several of the Eveready-brand pumps (distributed by Sears) proved to have a incredibly thick zinc galvanizing that coated every exterior surface, plus they had interchangable internal parts. Most of these came with a 1/3 hp, 1725 rpm, AC motor but work fine at speeds much slower than that, which makes them more versitile than centrifical pumps. These pumps were designed to last for years and to be rebuilt on the farm by someone with modest mechanical skills. The only parts that wear out regularly (every 5-10 years) are leather piston-cups and the cord packing around the pushrod. The valves are hard rubber washers and can be fashioned out of scrap (rubber tires or flip-flops, even). The brass cylinder is similar to a car's wheel cylinder from a drum brake, and although some of these are occasionally scored, they are easily smoothed with an automotive brake-cylinder hone on an electric drill.
After a little cleanup and repair, we had a functioning pump that sported a spiffy new paint job. I wanted to have several different drive possibilities to experiment with, so I rounded up a couple of DC motors (12-30 volts; industrial surplus supply catalogs are a good source for these). The motor I liked best was an 18 volt, 4.1 amp continuous-duty permanent-magnet D.C. motor made by Indiana General. With the help of a friend we found six used, quad. lam. solar panels from the now-defunct Carissa Plains solar power utility in California. These were an odd color and had no frames, but the price was right! We made frames and mounts from aluminum and steel, respectively, obtained by dumpster diving in the metal bins at our local recycling center/dump. The wire and plumbing were also salvaged. The wood and shingles for the pump-house were from a house demolition in our neighborhood. Almost everything in the project was salvaged or recycled, and our total costs were less than $350.00.
The great thing about solar pumping is that on the brightest days you usually need water the most, and these are the days that your pump delivers it! With the panels wired to the DC motor, we get 4-1/2 gallons per minute, at 35 psi. During midsummer we can pump for up to 14 hours a day, in moderate cloud cover to full sun. That is 3780 gallons per day in high summer. For $350.00 and a little elbow grease, that's not bad in anybody's book. This kind of system could be used to fill a holding tank at higher elevation, or, with a pressure switch for motor protection, hooked to a pressure tank, or just run directly to hoses and sprinklers or a drip system.
The combination of the classic looks of these antique pumps and the magic of direct photovoltaic power (a system involving no batteries) is fascinating and FUN! People stand by the panel-and-pump array and watch, listening for many minutes to the soft slap-and-hiss of the piston - when was water pumping ever this enjoyable? But with all this fun and coolness (remember, it's cool to recycle) the best part is the education. Put together a project like this and you will become a relative expert in solar pumping in no time. So get out there and recycle some water for yourself, and do it today!
Grainger Industrial Supply: replacement parts and pressure switches. www.grainger.com
Surplus Center: motors. 1-800-488-3407 (for catalog)
C and H Sales Company: motors. 1-800-325-9465 (for catalog)