December 1, 2010

5 Min Read


Robert Lowry often finds himself staring at a digital meter on his farmstead to see just how much power his new on-farm wind turbine is generating.

After Lowry put up two new grain bins at his Somers, IA, farm, his tab for electricity at MidAmerican Energy Company jumped from a few hundred dollars to $1,500/month during the postharvest drying season. The 35,000-bu. bins, installed in 2007 and 2008, each had two 12-hp. fan dryers. Lowry had several smaller dryers on his existing bins, as well.

The added energy costs, plus a belief his 7¢/kilowatt (kw) rate will climb when MidAmerican’s rate freeze expires (2013), led Lowry to reduce his reliance on purchased power.

Meanwhile Iowa, with its wind-friendly topography and transmission lines, surpassed California in 2008 as the second top wind-power-generating state behind Texas.

So it’s not surprising that Lowry’s thoughts blew toward an on-farm wind generator as he contemplated alternative energy options.

With 90,000-bu. storage capacity, “I knew I had enough grain-handling capacity in one location so I started looking into it,” says Lowry, who grows corn and soybeans with his son Matt.

Lowry paid $750 for Earth Linked Wind Solutions of Story City, IA, to perform a feasibility study. Earth Linked’s consultants evaluated Lowry’s site to make sure there weren’t trees, slopes or large structures to prevent prevailing winds from reaching a turbine. According to the Iowa Energy Center wind maps, Calhoun County has an annual average of 15.7-17.9 mph, well above Earth Linked’s recommended minimum of 12.5 mph.

In addition, Earth Linked reviewed Lowry’s power bills. According to Earth Linked consultant Jeff Smith, turbines are typically economical when operators use a minimum of 25,000 kw-hours (kwh)/year. Lowry was using not quite 80,000 kwh for his grain storage system, farm shop and homestead.

Typically, wind power produced by an on-farm turbine is fed into the operator’s local utility grid. Power for the operation is then supplied back by the power company. One plus for Lowry was that MidAmerican permits an indefinite net-metering system, allowing him to store retail electricity credits from months when excess power is generated and apply them when he needs them. Net metering is not available in some states or with certain utility companies, and some companies stipulate annual cutoffs when credits must be used.

“Basically, a net meter is running backwards, so power can be stored for fall when use is more than production,” says Smith.

Once Lowry’s project was deemed feasible, Earth Linked planned and installed a three-phase Windmatic 65-kw wind turbine mounted on an 84-ft., galvanized-steel lattice tower. The tower is set in four, 4-ft. diameter x 15-ft. deep cement braces.

Lowry’s turbine, with three 25-ft. blades, was a reconditioned model, and a new digital controller was installed. The controller performs various functions, including keeping the turbine rotor facing into the wind as the wind direction changes.

“If winds don’t stay above 7 mph, it will shut off,” says Lowry. The turbine also shuts off when wind speed hits 56 mph because the machine is not built to operate efficiently above that level. “The most efficient is 38-mph wind speed for this model,” says Lowry.

The turbine has one large generator that produces the bulk of power and a second smaller generator uses electricity to boost the larger generator at lower wind speeds and also adds power-producing capability at higher wind speeds. Because Lowry’s site is on a single-phase utility line, he had to buy a converter to feed power from the three-phase turbine. Lowry purchased a two- to five-year warranty for service through Earth Linked.

Earth Linked estimates that Lowry’s turbine will generate approximately 120,000 kwh/year. “In the first three months I produced an average of 10,000 kwh/month, which is on track for what they told me,” Lowry says.

In addition to the net-meter, Lowry has a separate meter for electricity used in his homestead which was needed to qualify for various grants and incentives.

A USDA Rural Development REAP (Rural Energy For America Program) grant paid for 25%, or $50,000, of his $200,000 total project cost. Earth Linked’s grant writer helped Lowry complete the considerable grant documentation. (For more on REAP, go to

Lowry also obtained a zero-interest Alternate Energy Revolving Loan Program (AERLP) loan through the IEC for 37.5% of the project (funding up to 50% is available). There are also federal stimulus tax credits and treasury grants available for wind turbine projects for 30% of the project cost. Some states, such as Ohio, offer additional incentives for on-farm wind turbines, according to Smith. “Potentially, people in Ohio can get 95% of their project paid for if they quality for all three programs,” he says.

In addition to grants and tax credits, small wind turbine projects may receive 50% first-year bonus depreciation under the American Recovery and Reinvestment Tax Act of 2009.

For excess kwh accrued, Lowry will receive Renewable Energy Certificates (REC) or green credits he can sell. “One green tag (1,000 kw) is worth $10-20 depending on the market. If cap and trade ever comes to be, then you’ll see the rate for green credits skyrocket,” says Smith.

Lowry expects the turbine to pay for itself in seven years. Smith says exact return-on-investment depends on what you pay per kwh for electricity, what percent of production is used, what finance incentives are applied and green tags prices. “We like to see a four- to eight-year payback,” Smith explains.

He says there is a high demand for small wind generators; planning and obtaining grants doesn’t happen overnight. “It could take six months from the inception to installation,” he says. Earth Linked project costs run between $120,000 and $600,000 for turnkey installation.

For more information on small wind turbines, visit or the American Wind Energy Association at For more information on state incentives, visit For information specifically on REAP grants, visit  n

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