Using PVs to Pump Deep Wells Richard Perez What can we do when the water lies deep down the well and all we have for power is sunshine? Well, thanks to the folks at SolarJackª and Kyocera, we can get along quite nicely. Read ahead and see how this family pumps their water from 400 feet down using sunshine. The Situation Don & Carly White live on a mountainside near Jacksonville, Oregon. Their homestead requires a water system that could pump water from a deep well and do it without commercial power. The Whites estimated that they needed about 1,000 gallons of water daily to support their homestead and garden. They sought the aid of Electron Connection Ltd. in solving their water pumping problems. Here are the facts of Don & Carly's water situation. The Well The well was already in place so this factor was given (wells being difficult to move). It was drilled, with a 6 inch steel casing, 512 feet deep. The static water level in the well is 120 feet down from the top of the casing. According to the records of the well drillers, the main flow of the well is 9 gallons per minute (GPM) and is located at approximately 480 feet down from the top of the well casing. The Site The site surrounding the well has excellent solar insolation. Wind is minimal at this location and no microHydro potential is present. The water from the well has to be pumped an additional 75 vertical feet from the well head to the 3,600 gallon water storage tanks. Possible Solutions We considered all the options. Wind powered jack pump, submersible deep well pump powered by either 120 or 240 vac from either a generator or inverter, and a PV powered solar jack pump were considered. The Whites selected the PV powered SolarJackª pump because it is quiet, reliable, and does not require the use of generators, inverters, batteries, or commercial power. The SolarJack Pump SolarJack pumps work in much the same manner as the jack pumps used for years on wind mills. The pump itself is a piston type and is located deep down the well. In the White's case, 399 feet down from the top of the well casing. The piston and cylinder are attached to the 2 inch diameter steel pipe that extends down the well. In the Whites case we used 19 sections of steel pipe each 21 feet long. The pump piston is mechanically activated by a fiberglass rod that connects the piston to a power source at the well head. This rod rides within the 2 inch galvanized pipe which brings the water to the surface. The power source at the well head lifts the fiberglass rod and all the water in the 2" pipe from the piston to the well head and beyond. The cylinder on the SolarJack we installed is 1 and 7/8 inches in internal diameter, and the finished setup had a piston stroke of 7 inches. The advantage of the jack pump design is its ability to lift water from very deep wells without having to install an electrical motor within the well casing. The power source for lifting the rod is at the well head. The motion of the pump is really slow in comparison with other types. Slow motion means reliability. In this case, the fiberglass rod was being lifted about 30 times per minute. INSERT PUMP GRAPHIC An electrical motor on the well head portion of the SolarJack provides the basic motive power for the pump. The motor used on this SolarJack is a 90 VDC,1750 RPM, Honeywell unit rated at 3/4 horsepower. This motor is geared down via a toothed belt & pulleys, and then through a gear case. The motion is translated into reciprocating up and down from rotary by a mechanical setup that closely resembles an oil pumping derrick. The derrick is coupled to the fiberglass rod via steel cables attached to a polished stainless shaft that passes through the well head seals. INSERT SOLARJACK PHOTO The electricity to power the DC motor is provided by eight Kyocera 48 Watt photovoltaic modules. The modules are series/parallel wired in a 4X2 matrix to produce an array with a nominal output of about 6 Amperes at 64 Volts DC or 380 Watts. The system uses no batteries. When the sun shines, then the pump operates. The SolarJack uses a Linear Current Booster (LCB) to make the DC power from the PV array more compatible to the motor (see Larry Elliott's article on LCBs in this issue). The Installation This turned into a real saga. The first detail to consider was a base for the pump to stand on. The SolarJack is a big mother- weighing in at some 300+ pounds or so. We opted to pour a concrete slab that surrounded the well casing. This slab would allow us to position the SolarJack precisely over the mouth of the well casing. Alignment between the polished stainless steel rod sticking up from the well seals, and the working head of the SolarJack must be within 1/16 of an inch. The slab we poured was 4 feet wide, 6 feet long, and 16 inches thick. We used two layers of steel wire mesh as reinforcement. We, at Electron Connection, enlisted the aid of Gene and Pat of Gene's Pump Service in Medford, Oregon to install the pump down the well. We needed to lower the pump piston/cylinder assembly, the 399 feet of 2" pipe and the 399 feet of fiberglass rod into the well. The weight of this assembly required a truck with a boom and a gas operated pony engine. INSERT PHOTO DOWN THE WELL Once the pump, pipe and rod were properly fitted and lowered down the well, the seals and polished rod were installed at the well head. Next the pump was positioned properly and secured to the concrete slab with eight 3/4 inch in dia. by 3.5 inch long lead anchors and lag screws. The job of drilling the holes in cement precisely was difficult and redrilling was necessary on the pump base to get everything to line up. Use a heavy drill for this job and drill the holes one at a time. Install each mounting bolt before drilling the hole for the next. After the pump was secured to the slab, we attached the polished rod to the working head with the steel cable harness. The pump was now ready to operate once it had a power source. PHOTO OF PUMP CREW We racked the PVs using slotted steel angle and cement piers. This arrangement is strictly temporary. The PV are to be moved to the roof of the pump house as soon as Don White gets it constructed. Once the PVs were racked and wired we hooked it up and took it for a ride. We flipped the ON switch on the SolarJack's LCB and the motor immediately started and the pump came up to speed. About 30 strokes per minute. We waited until the pipes filled to the holding tanks, and adjusted the counterweights as per SolarJack's instructions. Pump Performance The sun shines, the pump pumpsÉ all day long. The output of the system is some 1,170 gallons per day. The pump is not very noisy, we couldn't hear it from about 100 feet away. It runs without human attention. The White's don't even have to be home to pump their water. The sun shines and the pump pumpsÉ All day longÉ After hours of operation outside in the direct sun we felt the motor for signs of heat. The motor was only slightly warm, as it has a very good internal cooling fan. System Cost The cost of the SolarJack pump, complete with fiberglass rods, seals, counterweights and all other pump parts necessary for this system, was $6,451. This includes the concrete base and all shipping. Labor and small parts to install the pump down the well cost $658. The PV panels and their rack cost $3,088., installed and wired. The total cost of the entire system was $10,197., installed and working. Conclusion The SolarJack pump, and the Kyocera PV panels that power it, offer a real alternative for deep well pumping. The reliability of this system is supreme and justifies its additional expense over other options. Beyond the commercial power grid, all other alternatives involve using generators or inverters. These reduce reliability and efficiency. This water pumping system, using SolarJack and PVs, is quiet, ultra reliable, and should last for many years. This system provides dependable water anywhere the sun shines and the water lies deep. SolarJack makes all kinds of pumps for just about any application. You can contact Jim Allen at SolarJack Solar Pumping Products, 102 West 8th St., Safford, Arizona 85546 or call 602-428-1092. Kyocera America, the supplier of the PV panels, can be reached at 8611 Balboa Ave., San Diego, CA 92123 or call 1-800-421-5735 or in CA 619-576-2647. The system's specifier and installer is Electron Connection Ltd., POB 442, Medford, OR 97501 or call 916-475-3179. We are pleased to answer questions or supply information about this system.