U.S. Department of Energy Office of Energy Efficiency and Renewable Energy U.S. Department of Energy Energy Efficiency and Renewable Energy
  • Printable Version
  • Bookmark and Share

Wind Power Pioneer Interview: Nolan Clark, U.S. Department of Agriculture

R. Nolan Clark

R. Nolan Clark, laboratory director, U.S. Department of Agriculture (USDA) Conservation and Production Research Laboratory, Bushland, Texas. (PIX11922)

Wind Power Pioneer Interview: Nolan Clark, U.S. Department of Agriculture

Date: 7/1/2003

Location: Bushland, TX

"Nolan started working on wind energy for rural applications in the mid '70s. His research experience includes wind power for irrigation, domestic, and livestock water pumping; wind turbine performance; wind/hybrid generating systems; and wind effects on sprinkler irrigation. The USDA and the Alternative Energy Institute at West Texas State University have installed and operated more than 60 wind turbines, most of which were prototypes or first production units. Nolan has received numerous awards for his ground breaking work in utilizing wind energy technology to meet rural needs." — Vaughn Nelson, West Texas A&M University

Tell us a little about yourself and how you came to be the director of the United States Department of Agriculture (USDA) Conservation and Production Research Laboratory in Bushland, Texas.

A. My academic training is in agricultural engineering with a specialty in irrigation. I was hired by the USDA-Agricultural Research Service to develop a research program to improve the efficiency of sprinkler irrigation systems for the southern Great Plains, which includes parts of Kansas, Colorado, Oklahoma, New Mexico, and Texas. The greatest problem with sprinkler irrigation in this region is the wind's effect on evaporation and other water losses. After working at the Bushland Laboratory for a number of years, I was assigned the task of Director of the Conservation and Production Research Laboratory. This is my tenth year as director.

Q. When did you first become involved with wind, and what aspect did you direct your early work toward?

A. The USDA-Agricultural Research Service was one of the original federal agencies that were tasked to work on wind energy issues in 1974. We were assigned the Rural and Remote Applications area to conduct research and to coordinate with the other agencies. I was assigned the task of developing wind-powered irrigation and water pumping systems as part of this work. I installed our first wind turbine in 1976 and have been working with water pumping systems, as well as other wind systems, since that time. At the USDA, our focus has been on wind systems for remote areas with a concentration on water pumping systems.

Tell us about some of the wind energy projects that you have been engaged in over the years.

A. Our first efforts were mostly devoted to water pumping using mechanical pumps, but I soon began working with electric systems. At our laboratory, we tested the first Carter 25, the second Enertech 44, a 100-kW vertical-axis wind turbine that was later modified to become the Flowind machine, and the second Windtech machine. These four machines were installed in large numbers in California in 1984-86 after we had tested them in 1980-84. In the mid-1980s, we developed the wind-electric water pumping system using standard electric motors and pumps. Today, several wind turbine manufacturers around the world market a water pumping system based on our technology.

Probably one of our most controversial projects was the documentation of changes in rotor performance due to surface roughness changes on the blades. Several turbine manufacturers questioned our data and were skeptical. Later, when wind farm operators began washing blades and proving that bugs on the blades affected performance, our work become accepted.

Through the years, we have worked closely with Sandia Laboratories on vertical-axis wind turbines, and we were part of the design team that designed and constructed the 500-kW vertical-axis machine. We have also worked closely with the National Renewable Energy Laboratory (including all the groups that preceded NREL) on wind turbine design and performance issues. Over the past several years, we have conducted several studies on wind-hybrid systems for remote electric power generation. We have tested almost 75 wind systems over 25 years and currently have 13 wind systems operating in various experiments.

Q. What was your most interesting project?

A. This is a difficult question! All the projects have been interesting. But I think some of the early projects were more challenging and interesting because we knew very little about how systems might work, and we didn't have a clue about what might happen.

The design and construction of the 500-kW vertical-axis wind turbine was the most involved project because each piece, including individual bolts, had to be ordered, received, and sorted for proper assembly. That effort gave me a good appreciation for the manufacturing side of wind turbines.

Q. What was your most challenging project?

A. The first projects using the variable-voltage, variable-frequency concept were challenging because we were doing just the opposite of everything you learned in school and read in reference books. It was very gratifying when we demonstrated that the concept would actually work and that the pumps would operate.

Working with wind systems for remote applications, often without a utility grid, presents many challenging opportunities that do not exist with utility-connected machines. These challenges often exist in the areas that are least expected, like releasing brakes to start a wind turbine or locking a brake after the turbine has stopped, all without electricity.

Q. What was your most important project, as far as contribution to the wind industry/art?

A. Our research program at USDA-Agricultural Research Service has been such an integral part of the U.S. Federal Research Program that there are many contributions. I think the early definition of required sizes for rural uses and irrigation, which led to the development of the 50- to 100-kW machines that first established the wind farm concept, was extremely important. The remote wind-electric water pumping systems that are presently being installed in remote areas are equally important.

The development and demonstration of money-saving wind-hybrid systems for use in remote villages meet another need. And finally, although small wind-powered water purification systems that provide safe drinking water in remote and emergency situations have not been widely accepted, they are the subject of great interest.

Q. What are the most significant challenges facing the agricultural industry in deploying wind to benefit the farmer/rancher?

A. Money! Farm income is poor. Prices of farm products are almost the same as 50 years ago. Farmers have to produce 25 to 30 times as much corn, wheat, etc. to get the same buying power from each acre of land as their grandfathers had. This makes it extremely hard to invest in machinery or wind systems.

Many have contacted me about installing wind machines and selling electric power. Farmers are looking for any new income source because they are not making it with traditional farming.

Q. What needs to happen to fully engage the agricultural community with wind energy?

A. The financial institutions that finance farming operations need to be informed of the new potentials of wind energy. Most of the information that is being circulated is old stuff that reflects the status of the industry 20 years ago. State and regional seminars and workshops conducted by the Wind Powering America team and others help, but we need additional information, and we need projects.

Another problem is that our manufacturers have created a void in machine availability for the ag community. Small wind turbine manufacturers offer machines that are smaller than 10 kW (for the most part), and then 660- or 750-kW machines are the next smallest models. So except for a 50-kW machine, we now have this void of machines in the 100- to 250-kW size. The ag community could use an intermediate-size wind turbine, especially in the irrigation market.

Q. What role can the USDA play in moving wind energy implementation forward in the ag community?

A. The USDA has many agencies that work directly with the community leaders. I am in the research agency and therefore have little direct contact with producers and even less contact with policy makers within the Department of Agriculture. The Farm Services Agency and Rural Development Agency are the two agencies that have the most influence on implementing programs within the ag community. We do work closely with Extension Service to provide education on wind energy and energy efficiency.

Q. What are the prospects for wind-biodiesel hybrid power systems for the farm?

A. We are currently working in this area because of a need to develop small-scale biodiesel systems for farm use. Biodiesel has been successfully used to power normal diesel-electric generators, either as single units or as wind-hybrid units. You should see biodiesel systems installed at several locations over the next 3-5 years.

It is now an education issue rather than a technical problem. We know how, we just need the money to make it happen. The increase in natural gas price may make these systems appear rapidly in the coming year.

Q. If you had an unlimited budget, what two to three projects would you propose that would move wind into the mainstream of ag applications?

A. I would install a 200- to 250-kW wind turbine in the dry corner of a center-pivot sprinkler system and demonstrate the potential of using wind power to pump water during the growing season and supply heat energy during the winter. This would reduce the dependency on natural gas for many of our Great Plains producers.

Another project would be to develop a hybrid wind-fuel cell concept for producing electric power in any location. Wind power would be used as a supplement to produce the fuel needed to power the fuel cell, whether it be hydrogen, methane, or biodiesel. This system would be 100% renewable and could be transported to any location.

Lastly, I hope that we soon realize that everyone in our world could have access to clean, safe water to drink. Affordable water pumping and purification systems could be developed and provided to all nations and all people.

Q. Is there anything else you'd like to mention?

A. I have no regrets about spending more than 25 years working to make wind energy available to anyone and everyone. I hope in some way that my efforts have made life easier and provided many people with a healthier, happier life. I want to think that my research has made a difference in our world.

This information was last updated on August 02, 2011