
The Solar Array
Gaining Ground Farm Goes Solar
By Michael J Paine, Farmer
More than three years ago we began to imagine how we could reinvent the irrigation systems at Gaining Ground Farm. The most challenging issue for us has always been electricity and how to irrigate without it. We have no power in or even near the fields and no interest from the power company to add us to the grid without significant investment from us. For our first three years (and the better part of the three that followed) we used high pressure, gas powered pumps to push water all over the property. While these pumps were efficient as high-pressure movers of water, they created numerous challenges to our system. Being gas powered, they needed to be refilled every two hours and several times a day someone would have to stop working to make the trek to refill the pump. Additionally, because of the pressure and volume that these pumps moved our irrigation water at, we were forced to use handlines and overhead sprinklers instead of more efficient driplines. This increased weed competition and demanded more man hours in order to remove weeds and to move the handlines across fields according to our irrigation calendar. We needed a change.
Early on in researching how a solar pump system would work, I went to the Yamhill Soil and Water Conservation District and I asked Mike Crabtree what his thoughts were. From that point on he and the conservation district were crucial partners in the design and implementation of the project. By combining cost share through Organic-EQIP program and Oregon’s OWEB program (Oregon Watershed Enhancement Board) we were able to make this project a reality. An essential part of this project was being able to work with John Gillilan, a USDA engineer, who took our rough idea and ensured it was as safe and efficient as possible. Before this project, a solar pump system had not been implemented in an irrigation scenario making this project a unique challenge to engineer.
The system was completed in the summer of 2010. A 2-kilowatt solar array powers a solar specific pump (made by Sunpumps). During solar hours of the day the pump pushes water up the hill to 10,000 gallons worth of storage tanks. The system then uses gravity flow to power the drip irrigation system in the fields below. By usingcomputerized valves we are able to increase our irrigation efficiency by pulse irrigating on the shoulders of the day and through the night. This system is also tied into an adjunct rainwater catchment system that catches rainwater off of our house and shop and directs it to the holding tanks. The overflow from the tanks then gets routed back down the hill, via a drainage pipe, to the irrigation pond.
The benefits of this system are compelling. It seems possible that we can cut our water consumption in half and at the same time increase the efficiency of our water delivery to our crops. Also there are erosion control benefits from the thousands of gallons of water that would run off our buildings roofs now being captured for use in irrigation. The estimated water savings over 5 years is 203,730 gallons that will not be taken from the aquifer. Personally, between the time we used to spend directly on irrigation and time saved from cultivation, we might have several hours per day that we can dedicate to other farm activities. I hesitate to add we might even be able to take a day off.

Tanks Installed at the Top of the Hill

Mike Paine Showing Participants of a Water Conservation Tour the System’s Filter Bank

Mike Paine Showing the Sunpump in the Irrigation Pond