A mill owned and operated for six generations by the Weisenberger family has been grinding grains in the heart of Kentucky since the Civil War. In 1862, August Weisenberger emigrated from Baden, Germany, to start milling grains in Midway, Kentucky. He purchased the existing three-story stone mill on the banks of South Elkhorn Creek in 1865—the perfect location to harness water power to operate the mill.
By 1913, the old mill had become structurally unsound and was demolished and later rebuilt. The family also replaced the water wheel with more efficient twin hydropower turbine and generator units, boosting their local electric supply. As the family-owned business—Weisenberger Mills Inc.—grew and added more equipment through the years, they supplemented their onsite power generation with electricity from the local utility.
More recently, with a $56,000 Energy Department award, Weisenberger Mills installed a generator and power electronics in 2013. The new system utilizes water flowing through the turbines more efficiently, generating enough power to run the mill when it’s grinding grain. Eventually, the generator will operate 24/7 and produce more than enough power for all the mill’s needs; and using net metering, Weisenberger Mills may even sell back electricity to the utility as needed.
Equipped with a permanent magnet generator controlled by a variable speed drive—a device where magnets rotate around conducting wires to generate electricity—the new system better captures the varied flow of the creek, which results in improved annual energy production. Small hydropower projects like this, ranging between 100 kilowatts and 30 megawatts in capacity, can efficiently convert energy from low-head stream flows and often use existing infrastructure with little to no environmental impact.
These days, other than the new generator, most of the mill’s operations of grinding, mixing, and sifting are done using circa-1913 machines. The mill grinds about 1,000 bushels of grain a week and buys all of it from within 100 miles of Midway, further reducing the mill’s overall carbon footprint.
Today, hydropower remains the most common and least expensive source of renewable electricity in the United States. According to the recently released hydropower market report, roughly seven percent of the country's electricity is produced from hydropower resources. To learn more about hydropower’s role in the energy mix, please visit the Water Power Program website.