USE OF WIND TURBINES IN THE SPIRIT LAKE, IOWA, SCHOOL DISTRICT: A WIND-WIND SITUATION. Spirit Lake, Iowa Community School District

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1 USE OF WIND TURBINES IN THE SPIRIT LAKE, IOWA, SCHOOL DISTRICT: A WIND-WIND SITUATION Jan Bolluyt 1, Tim Grieves 2, and Jim Tirevold 3 1 Physics Teacher 2 Superintendent 3 Director of Buildings and Grounds Spirit Lake, Iowa Community School District Editor s Note: Jan Bolluyt served as the main contact at Spirit Lake High School in the preparation of this article. He coordinated responses to the questions by working with Dr. Tim Grieves and Jim Tirevold. The school district makes use of two wind turbines. The first, smaller wind turbine stands 140 feet tall on a pad and pier base and has an 87-foot rotor diameter. The later, larger wind turbine is 180 feet tall on a Patrick and Henderson foundation with a 158-foot diameter rotor. Dr. DeWayne Backhus, Chair of the Departments of Physical Sciences at Emporia State University, assisted with preparation of the questions. Go to the Spirit Lake School District web site ( and then click on wind energy for more information and a listing of additional resources. 1. What was the inspiration to have wind turbines built at the school site as an alternate energy source? The inspiration was sparked at a very windy flag football game that both our school board president, Craig Newell, D.D.S., and superintendent, Harold Overmann, attended. Newell commented that it would be exciting to be able to harness all the wind energy and make it into something useful. Newell pursued the idea and researched the possibilities. He then reported his findings to the school board. (Editor s Note: The main text of Newell s letter to Mr. Ron Brown of the Kansas City, MO Office of the Department of Energy is included at the end of this article. The format of the original letter was changed to accommodate the KST.) 2. What was the general timeline from when the idea was a serious consideration to completion of the second wind turbine? The idea was presented at the September, 1992, school board meeting, and the second wind turbine was on line in October of How many companies did you talk to before deciding on the wind turbines to buy? Which company(ies) did you use? The board determined the specifications that they found necessary for our elementary school building and based on the wind studies performed on the proposed location. The bidding process was open. Three companies bid on the first (smaller) wind turbine and two bid on the second (larger) wind turbine. The companies selected based on their bids and plans were Wind World and NEG Micon. Kansas Science Teacher Vol. 16, Spring

2 4. What were the lessons you learned in the process and which could/should be utilized by others? The main lesson that we learned was that persistence pays off. Our wind turbine was the first school experiment in the state. Negotiations with our current utility company, loan and grant applications, bidding procedures, wind studies, etc., were all new to us and took much more time than they would today. None of them could be avoided nor streamlined in the beginning. Schools with a plan to install their own wind turbine(s) should check with others in their state while developing their plans. A second lesson based on our experience is to recommend that a cost/benefit study be conducted. Although a bond issue was not necessary in our case, such an undertaking for a public school district needed justification from the get-go. 5. What issues were negotiated with the utility company (e.g., comment on cost incurred for connecting to the utility, how much is paid the school as a generator per kilowatt-hour (kwh) versus how much it costs per kilowatt hour to buy as a consumer,...)? The final outcome of our negotiations with the utility company was monthly net billing. This meant that meters were in place for both production and usage (consumption) at the school. Each month the total usage was subtracted from the production. If the outcome was positive, the utility company paid us at a rate of approximately 2 cents/kwh. If we used more than produced, we were billed at the current rate for our district (9.7 cents per kwh). Connection costs were part of the bid and compliance with the utility company was done on an hourly rate charge. Compliance involved compatibility of the wind energy generation interconnection with the utility company distribution system. Specifically, this included the means of connection to the grid, voltage fluctuation maximums, power load protection, relays, etc. 6. What is the capacity (kilowatts) of the first, smaller wind turbine?... of the larger wind turbine? The first is a 250 kw turbine; it is producing approximately 300,000 kwh/ year. The second is a 750 kw and is producing 1.7 MWh/year. 7. What are the cut-in speeds for each wind turbine? For the smaller wind turbine the cut-in speed is approximately 8 mph with a range of generation up to 50 mph. For the second it is 5 mph, with a range also up to 50 mph. 8. What are the generating capacities (kilowatts) of the wind turbines at the cut-in speeds? It is 19 kw for the smaller generator and 50 kw for the larger. 9. What are the generating capacities (kilowatts) of the wind turbines at their peak wind speeds? The generating capacities are 250 kw and 750 kw. Kansas Science Teacher Vol. 16, Spring

3 10. What percent of the time is each wind turbine at peak production? This information is not available. Our wind feasibility study gave us predicted outputs, but I did not have access to that study. Also, our monthly data output is in total production, not in instantaneous production. I do believe that we can print a graphic production report that can be interpreted for such data, but we have not done so. 11. What percent of the time is there no generation? Again, we have not collected that data. There is instrumentation available to record this information, but we do not have it attached to either rotor. 12. Does the first, smaller wind turbine energize only the elementary building? The yearly production of the smaller turbine is approximately the same as the kwh consumption in a year by the elementary school building. It was designed to match the usage of that building. 13. What is the typical kwh per year generation by the first wind turbine? The production of the first, smaller wind turbine is 300,000 kwh. 14. What is the typical kwh per year generation by the second wind turbine? The production is 1.7 MWh (mega-watt hours). 15. What load (percent of annual consumption) is the second, bigger wind turbine providing for its consuming source? The second generator produces approximately the same amount of electricity that is used by the rest of the school district; we are at about 100% usage/production when both wind turbines are included. We have an elementary building, middle school, high school, district office, industrial technology building, and maintenance building that are all included in the comparison of wind energy production and consumption. 16. Does the combined production meet the school s yearly demand? At our current size, yes, it does meet the demand. All districts are dynamic. We are currently finishing a middle school classroom addition and planning for a high school auditorium and gymnasium complex. Those changes will increase our electrical needs beyond our current production. Some discussions are underway to increase the capacity to meet demand. 17. How does the energy consumed by the district compare to energy produced by the wind turbines? If the school district makes a profit on costs of wind turbines and energy/power used versus energy/power produced, how does the money saved or earned allow the school to do other things? The two, currently, are almost the same. Because our payback is only 2 cents/kwh and yet the cost of purchasing the same is now 9.7 cents/kwh, it would not pay for us to go into the production of electricity for our utility company. We currently are using what would be our estimated costs for electricity to pay off the loan on the second generator. We feel that the cost savings is approximately Kansas Science Teacher Vol. 16, Spring

4 $130, per year allowing us to hire 2.5 more professionals on staff, or fund our programs to that extent. When our loans are paid (2-3 years) and the cost of electricity increases, our savings will also increase. 18. How has the presence of the wind turbines affected or impacted the K-12 curriculum? It has affected the curriculum immensely. Wind energy-related topics are crosscurricular including mathematics, science, government, language arts, art, etc. We also include these topics at multiple grade levels. I could mention all the curricular changes that have taken place, but you do not have the space nor the time. I will mention a few to whet your appetite. The first-grade class wrote a book about Curious George and the Wind Turbine with each child writing and drawing a page using a question they had as motivation. The entire class then combined them (check our web page). The students visited the turbines and researched their answers. It was impressive. Our physics students teach the unit of electricity to the fourth grade students each year. They use old telephone generators, VandeGraf generators, etc., to introduce the concepts of electricity. The question and answer period always includes many questions about our wind generators. The third grade classes made wind toys and used the turbines as inspiration for a poem about wind energy. In algebra class the data from the wind turbines is used as real data for statistics, and the students derive the linear equations from a pollution calculator using data that they input. In physics class, the students build their own motors and generators after touring the wind generators. They learned the practical side of electricity generation, calculated cost savings, learned about electrical grids, brown-outs, metering, and so much more. The Spirit Lake High School government class was invited to the state legislature to discuss the implementation of wind energy for the Spirit Lake Schools. Students have been included in all phases of implementation. 19. What are some typical lessons (brief descriptions)? In addition to those mentioned earlier, here are some more examples: Middle school mathematics students use similar triangles to estimate the height of the wind turbines. The statistics class uses monthly data for statistical analyses. In business, students use the wind turbine data to determine cost savings, interest payments, etc. In speech class students do persuasive speeches concerning the pros or cons of wind energy production. Computer class students design a web presence for school wind data. CAD/CAM students design the wind turbine given its specifications. Kansas Science Teacher Vol. 16, Spring

5 In art students use perspective, vertical to horizontal proportions, drawing, lighting, and shadows. For reading/writing, the wind turbines are used as the subject of a writing assignment for different styles of writing such as Shakespearean, technical journal, etc. 20. Have perceived benefits (or problems) matched what has occurred? Provide some details. The problems that we perceived were as follows: It is a visual eye-sore: We have found that a few people feel it is an eyesore, but most agree that the benefits are worth the visual effects when compared to radio towers, telephone poles, billboards, etc. Some people even like the look! Sound pollution: That problem is moot. The decibel level is almost imperceptible unless you are listening for it and are very close to the turbine (30 db at 500 feet). Bird kill: We have not found the bodies of any birds below either tower since they were built. It seems apparent that they are able to easily avoid the turning blades. In comparison, there have been four birds killed by the picture windows in my house in the same amount of time! Ice thrown from the blades: This problem has not occurred since the beginning, but we do not have any playground equipment in the immediate area below the turbines. The velocity of the blades and the pull of gravity would place the ice in the shadow area of the blades themselves. 21. If there was opposition to the wind turbines, what reasons were given for the opposition? We were not aware of much opposition to the wind turbines. It did not cost tax payers any money what-so-ever, it was a reason for civic pride, it avoids pollution associated with conventional electrical generation, etc. Most people considered it a win-win ( wind-wind ) situation. The utility company carried double metering to the fullest extent, as the generators could represent a threat to their profit margin. Once all discussions and negotiations were finished, however, we do live in relative harmony. Kansas Science Teacher Vol. 16, Spring