As the world moves away from fossil fuels for energy generation, with their atmosphere-warming emissions and health-threatening pollutants, renewable energy sources are being researched and implemented. One of them is wind energy, described by the U.S. National Renewable Energy Laboratory as "one of the largest sources of clean, renewable energy in the United States, making it essential to a future carbon-free energy sector."

To convert the mechanical energy of the wind into electrical energy, wind turbines have blades or other moving parts. This means that there is a minimum wind speed needed for them to start rotating and a somewhat continuous wind to keep the turbine spinning at peak capacity. The U.S. Department of Energy estimates these wind speeds at about 8 mph (3.6 m/s) and 30 mph (13.4 m/s), the minimum and average sustained wind speeds, respectively.

Another limitation of current technologies is that the amount of wind power generated depends on whether the wind is blowing and how much. However, innovative ways to store wind energy when excess generation is available and then release it on demand are being studied nationwide. Two storage alternatives are batteries and hydroelectric systems that pump water up a reservoir so that it can flow downward to spin power turbines when power is needed.

In 2022, Kentucky had 68% of its electricity generated from fossil fuels, mainly coal and natural gas. Historically, the perception has been that the state is not windy enough for it to tap into wind energy for power generation. Other factors, like low electricity prices and the absence of state policies encouraging the local development of wind energy generators, have contributed to the fact that all states bordering Kentucky have wind power, but we do not.

In a recent study, Larry Holloway and Dan Ionel (University of Kentucky) and Aron Patrick (PPL Corporation in Louisville, KY) argue that new advancements in wind turbines and wind energy storage will allow Kentucky to tap this renewable source, particularly as a complement to solar power. Their findings were published in the Journal of the Kentucky Academy of Science.

After a detailed analysis, the authors reported that, at an elevation of about 380 ft (115 m), the estimated average wind speed in Kentucky is almost always higher than 12 mph (5.5 m/s), enough for current-generation wind turbines to start spinning. However, the estimated average wind speed in Kentucky rarely exceeds 16 mph (7.2 m/s), suggesting that the wind turbines may not be able to consistently reach peak power.

However, Holloway, Patrick, and Ionel noted that current advances in wind turbine designs allow better capture of wind energy, particularly in counties like Bourbon, Meade, Carlisle, Scott, Graves, and Harlan counties. With modern wind energy advances, a state that was not previously considered suitable for wind power could see wind become an important contributor to its mix of power sources. 

A 165-foot-tall utility-scale wind turbine in Mercer County is used to collect research data to quantify the potential of wind energy in KY. Photo courtesy of the Pennsylvania Power & Light (PPL) Corporation.

In the article, the researchers emphasized the importance of resiliency in power generation systems. Even if solar and wind energy cannot completely replace fossil fuels in the short term, if their contribution is 50%, that is half of the greenhouse gases and pollution emitted by coal, natural gas, and diesel.

They also showed year-long wind speed and sunlight intensity data from Harrodsburg. Solar and wind energy were found to be complementary. For example, in winter there are fewer hours of sunlight but higher daily average wind speed. In July, in contrast, there are more hours of sunlight but lower daily average winds. When working in tandem, they can provide energy reliably in combination with energy storage during off-peak power use hours.

“It is exciting to see this source of energy being explored for the state,” said Larry Holloway, one of the authors of the paper. “The first wind turbine in the state was installed by the Louisville Gas & Electric Company and Kentucky Utilities in 2024. We have been analyzing data over the first year of operation. Although recent analyses have shown that wind production at the initial site was less than expected, it did demonstrate that wind generation in the state is possible and can complement other sources. With larger and taller turbines currently on the market, wind could be a viable part of our state energy mix.”

Holloway, Patrick, and Ionel are hopeful that, as more evidence in favor of complementary solar and wind energy emerges, renewable energy production in the state will soar. They mentioned, for instance, wind energy projects recently installed by Louisville Gas & Electric and Kentucky Utilities, and a proposed wind development in Henderson County. Although solar is currently estimated at a lower cost than wind, wind energy can have an important role in Kentucky’s future energy mix.