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Kansas State University
Electrical and Computer Engineering
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Manhattan, KS 66506
Phone: (785) 532-5600
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Personal Webpage of Gary Johnson

Dr. Gary Johnson's Renewable Energy and Tesla Coil Page

Revised March 3, 2011

Dr. Gary L. Johnson taught electrical engineering at Kansas State University for 28 years before taking early retirement in 1994. He wrote a textbook "Wind Energy Systems" which was used in a senior elective course for many years. Prentice-Hall let the book go out of print and gave the copyright back to Dr. Johnson. The revised and expanded version was then used for several more years. This textbook is available at no charge in a .pdf file listed below. contains 134 slides, mostly taken by me, that might have some historical interest. Please send Dr. Johnson an email at, telling him of the download. That will help justify keeping this site open.

Windbook.pdf (8.1MB) 134 slides (48 MB)

Dr. Johnson built and tested a 5 kW Savonius turbine in the mid 1970s. The peak efficiency was in the range of 30 to 35% but it was judged to not be economical so research was abandoned. Dr. Johnson was asked to visit a start-up company in Newfoundland in December, 2010, to look at their concept of a harsh weather Savonius. The concept was interesting, but the payback period was over 20 years, which makes the concept dead in the water. They were off in their calculation of payback by a factor of eight! As of early March, 2011, they have still not reimbursed Dr. Johnson for his travel expenses.

Course Lectures Available on DVD

Dr. Johnson's course on Wind Power was videotaped (for Distance Learning) the last semester it was taught. The 41 videotapes have been compressed into .avi files such that the entire course fits on one DVD. Dr. Johnson speaks slowly and writes clearly, so the lectures would be useful to those who want to improve their understanding of spoken technical English. Some lectures would also be useful to newcomers to the field who want to learn about wind statistics, wind farm layout, etc. Send Dr. Johnson your mailing address and he will mail you this DVD, for free. You can then copy, distribute, give away (or sell) this DVD to others, as you wish. If your mailman does not read English, send your address in a .jpg format so it can be copied and taped to the front of the mailer.

Dr. Johnson collected wind data at what has become the 150 MW Elk River Wind Plant located near the small town of Beaumont, Kansas (east of Wichita), for about 10 years. There were two 40 m towers most of the period and a 60 m tower for 2.5 years. The following comma delimited files give the average wind speeds in m/s over all the working anemometers at 10 m and at 40 m for each hour. The files also include wind direction and temperature.

elkriv95.csv 1995 hourly data
elkriv96.csv 1996 hourly data
elkriv97.csv 1997 hourly data
elkriv98.csv 1998 hourly data
elkriv99.csv 1999 hourly data
elkriv00.csv 2000 hourly data
elkriv01.csv 2001 hourly data
elkriv02.csv 2002 hourly data
elkriv03.csv 2003 hourly data
elkriv04.csv 2004 hourly data
elkriv05.csv 2005 hourly data

In addition to traveling and other retirement activities, Dr. Johnson has been investigating Tesla coils, especially the Extra coil directly driven by a solid state inverter. A summary paper on Tesla coil impedance (presented at The First Tesla Museum and Science Center International Conference on Nikola Tesla, Farmingville, New York, October 6-8, 2006) is in TeslaCoilImpedance.pdf. History and theory are covered in six chapters, the inverter and associated equipment are described in Chapter 7, and data and comments in Chapters 8 and 9. Comments and questions can be addressed to

TeslaCoilImpedance.pdf Tesla Coil Impedance (3.2MB)
tcchap1.pdf Introduction (103 KB)
tcchap2.pdf Ideal Capacitors (97 KB)
tcchap3.pdf Lossy Capacitors (167 KB)
tcchap4.pdf Inductors and Transformers (139 KB)
tcchap5.pdf Lumped RLC Model (93KB)
tcchap6.pdf Resistance (148KB)
tcchap7.pdf Tesla Coil Driver (519KB)
tcchap8.pdf Data (156KB)
tcchap9.pdf Comments (68KB)
p213a.jpg Spark Picture

Dr. Johnson has also been interested in finding yet another source of energy for the past two decades. He wrote and self-published an eight chapter paper-back book called "The Search for a New Energy Source" which details part of his literature search on this exciting topic. It is available in pdf below (free). If you want a paper copy of the book, email Dr. Johnson with your address and he will mail you a copy by the cheapest method. He has just finished writing a larger document, Religion, Science, and PSI - The Search For a New Energy Source, which is available, free, as PsiEnergy.pdf, below.

Search1997.pdf The Search For A New Energy Source (Originally published 1997) (665KB)
PsiEnergy.pdf Religion, Science, and PSI - The Search for a New Energy Source (1MB)