Farmer powers irrigation system with solar energy

WHITING, Ia. – Dolf Ivener turned to sunshine to water his cornfield this growing season.

Ivener powered a center-pivot irrigation system with solar energy. It’s among the first of its kind nationally.

He designed a photovoltaic system based on the average hours of daily sunlight the Sioux City region receives each season.

An array of 22 solar panels, measuring 3 feet by 6 feet, produce around 300 watts each, or 11,000 kilowatts to 12,000 kilowatts per year, enough power to pump water through the system’s pipes and propel its wheels around the field four times. That’s the average number of trips in a typical year for irrigated farmland like Ivener’s 160-acre tract southeast of Whiting.

Weather wise, this year was anything but normal, however.

On three different occasions, heavy rains flooded the Missouri River bottom land. The stubborn, wet conditions slowed the installation of the solar system, as well as the growth of the corn plants.

“You can see it’s not as tall,” Ivener said, pointing to the corn plants, some with yellowed leaves, as he drove his pickup down a dirt path to the center pivot.

With the Monona County field finally drying up, Ivener turned on the center pivot for the first time. But it was only to feed a late-season application of fertilizer through the sprinkler heads.

It’s possible the system won’t be used for irrigation at all this season.

“As much rain as we’ve had and as cool as it’s been, I wouldn’t be surprised if this year the pivot runs for even a day,” he said.

Still, Ivener views the technology as a sound, long-term investment.

It cost $23,000, but a 30 percent federal tax credit and an 18 percent state tax credit is covering nearly half the cost. The credits, claimed through filing income tax returns, are designed to encourage solar power.

If everything works right, the payback on the solar system would be 10 years, he said.

Ivener estimates it would cost $50,000 to $60,000 to run traditional power lines to the center pivot.

Before installing the solar system, Ivener worked out a 10-year deal with Western Iowa Power Cooperative, or WIPCO, a rural electric co-op that serves Monona and eight other counties. The co-op installed a bidirectional electric meter in the field. It measures how much power the solar panels produce, as well as how much excess electricity the array feeds back to the co-op.

“This year, I will end up producing too much power, and they will write me a check,” he said.

The rural cooperative will pay 4½ cents for each excess kilowatt, he said. But Ivener said he would rather get a credit on his account. That’s what state law requires investor-owned utilities like Mid­American Energy Co. to offer producers of solar energy, through a system known as net metering.

During drought years, Ivener said the irrigation system likely would need to run more often, requiring him to buy power from WIPCO at the agreed upon rate of 11½ cents per kilowatt.

Ivener is a Sioux City businessman who also is involved with construction and property management. A conversation four years ago with an uncle who worked in the renewal energy business piqued his interest in the emerging solar power industry.

“He told me the numbers don’t work now, but someday they will,” Ivener recalled.

Since they talked, the price of solar panels has tumbled about 80 percent. Combined with the tax credits, that’s helped put solar energy on a more level playing field with traditional power sources, he said.

Ivener has installed solar powers on some commercial buildings he owns in Sioux City, as well as a few businesses and residents. The solar systems work best in new construction.

He is building a four-unit apartment building on Sioux City’s north side along Hamilton Boulevard, near Mike’s Saloon, that is outfitted with an array of more than 60 solar panels.

The rooftop panels will generate enough excess power that Ivener will be able to offer tenants free utilities.

Three years ago, Ivener, with his two sisters, joined to start farming some acres his father, Kent, a retired farmer, had been cash renting. After learning irrigated land on neighboring farms were producing higher yields, the family decided to put in their own center-pivot system, fueled by the sun.

The solar-powered system has spurred numerous calls and field visits from commercial center-pivot installers, Ivener said.

Ivener said he is not looking to market his solar knowledge to other farmers. But he is considering putting in a similar center-pivot system next year at another field his family farms, near Hornick.