Farm tests solar-powered irrigation system

An experiment conducted by the Cape Girardeau County office of the USDA's Natural Resource Conservation Service is capturing the power of sunlight to provide fuel for irrigation. So far, the results have exceeded expectations, a local NRCS engineer said.

Since June, the NRCS has been testing the real-world application of using solar power to operate an irrigation system. Using 10 two-foot-by-six-foot solar panels combined into one solar array, Gordonville-area farmer Mark Wessell has been irrigating a 24-acre field.

Both Wessell and NRCS engineer Mark Nussbaum said the experiment shows promise.

"It would save a lot of fuel money," said Wessell, who used about six gallons of gasoline a day to irrigate the field the solar panel now irrigates. "I spend a lot of money on gas for the water pumps I have at other locations."

The experiment was initiated after Rep. Jo Ann Emerson secured a $15,000 federal grant to buy the solar array, Nussbaum said. Since the solar power supply test started in mid-June, the system has pumped about 1.5 million gallons of water. That's about 33,000 to 45,000 gallons per day -- well over the 25,000 gallons per day Nussbaum anticipated. Wessell said the pump even runs on overcast days.

Plenty of sunshine has been available this summer to power the system. The National Weather Service in Paducah, Ky., counted 28 sunny days in July, three partly cloudy days and no cloudy days. In June, 25 days were counted "fair" with only five partly cloudy days and no cloudy days.

"I think we were both a bit skeptical initially," Nussbaum said. "Solar energy traditionally has been a low-power output. But a steady dropping in cost enables these systems to pass the threshold where they can be installed in a real-world situation."

Since the array was purchased last fall, the price for a similar system has dropped from about $14,000 to $9,500, Nussbaum said. Almost half the system cost can be offset by special tax credits for renewable fuel technology, Nussbaum said.

Several states and the USDA are promoting the use of solar systems for pumping water.

Ten solar panels generate power to a pump that takes water out of Hubble Creek and into a subsurface drainage and irrigation system in Wessell's field. The solar array has limited application: It can only generate enough power for the low-energy subsurface systems, not above-ground irrigation methods, and the 10 panels are only ideal for smaller fields. Wessell has been using the solar panels to irrigate his 24-acre field, but said he could use more power-generating solar panels for the field size. He had plans Tuesday to move the solar-powered pump to a smaller soybean field.

Wessell said he plans to buy a similar system next year because he knows he'll easily recoup the cost by not having to use gasoline to pump water.

Nussbaum said as the panels continue to drop in price, he thinks more farmers will make the switch to the technology. Using the solar panels is cheaper in the long run than fossil fuel or having an electric provider run a "drop" to a field to power a pump.

Nussbaum said he selected a field that was bigger than the ideal size for the 10 solar panels to test the system under extreme conditions. So far the system has performed beyond expectations.

msanders@semissourian.com

335-6611, extension 182