What’s New About Windpower? Erich Zimmermann in 1933
Excerpt from Erich Zimmermann, World Resources and Industries: A Functional Appraisal of the Availability of Agricultural and Industrial Resources (New York: Harper & Brothers, 1933), pp. 556–58.
“The Place of Wind in Modern Energy Economy”
Not only are new uses of water as a source of energy being studied, but the power of the wind is likewise being subjected to renewed scrutiny. Two recent proposals are mentioned here in order to indicate the trend of this development. The first is a German proposal which was reported in a wireless from Berlin, February 11, 1932, as follows:
Harnessing the air for generating electric power is advocated by Hermann Honnef, an engineer, whose perfected designs for that purpose are engrossing the attention of scientists and technicians and may revolutionize the German electric industry. Honnef claims to have solved the technical difficulties in a way to efficiently convert the force of the wind into electric power and to overcome the drawback of the inconstancy of air currents which hitherto has been a handicap to the utilization of this source.
His plan is to tap the winds at altitudes of 1,000 to 1,400 feet by means of great steel towers equipped with gigantic windwheels several hundred feet in diameter. Such an aeroelectric unit, requiring 6,000 tons of steel for its construction, would generate 20,000 kilowatts a day, and so economically that a rate of less than a quarter of a cent per kilowatt hour can be figured out, the inventor asserts.
In expounding his project at the Physics Institute of the Charlottenburg Polytechnic, before physicists, electrical engineers and technical representatives of the Reich government, Herr Honnef emphasized that water power suitable for developing electricity was confined to certain localities and that hydroelectric plants were costly, whereas the winds were everywhere available and therefore the logical source for electric power. Forty to fifty of his power towers could be built annually in Germany, he said, and the low rate at which power produced by them could be furnished to consumers would lead to hitherto unthought [line missing]. He urged the immediate construction of a wind tower, preferably in Berlin, to serve the twofold purpose of initiating the new process and affording means for further observation and experiment. A representative of the Reich Transport Ministry suggested beginning with a smaller tower to be built for testing purposes.
The second proposal is based on the application of the rotor principle of Anton Flettner, whose ill-fated rotor ship attracted wide attention some years ago. It was seriously discussed by Waldemar Kampffert, an authority on scientific subjects, under the headline “Harnessing of Wind in New Jersey Plant May Hold Importance for Industry.”
An excerpt from the lengthy article follows:
Twenty rotors run on a circular track with a gage of 36 feet and a diameter of 3,000 feet. They are mounted on streamlined flat cars, each 40 feet long and weighing about as much as an ordinary locomotive, or about seventy tons. Steel cables link the rotor cars in endless trains which will not tip over even in a 100 mile-an-hour gale. As the axles of the cars turn, generators are driven. A kind of electric safety valve prevents overloading of the generators in a high wind. The current is picked up by trolleys or contact shoes and fed into the transmission system. We have in effect a sail-driven train running on a circular track embracing about 200 acres of land.
It is evident that as they circle around the track the rotors must change direction of spin, so that there will be no interruption in the generation of electric energy.
A weather vane mounted on top of each rotor automatically actuates a switch which thus reverses the electric motor by which the rotor is turned. The electric energy required to turn the rotors is taken from a separate trolley wire. Only a small percentage of the total indicated output of the plant is needed to spin them, hardly more than what would be lost even in a steam engine in overcoming the friction of moving parts.
The speed at which the rotors turn determine the extent to which the wind is utilized. If that speed is reduced or increased the power output is changed proportionately. When the speed is zero the train stops, even in the stiffest gale, because the forces around the track are completely balanced. The track speed is maintained automatically, so that the output will increase and decrease with the wind. Tests on small models show that a train will start itself at a wind velocity of only six miles an hour—a light breeze.
It is of interest to note that the scheme does not contemplate the use of storage batteries. The wind rotor power plant is to be used in much the same way as peak hydro- or steam plants are now being used. That the perfection of an economical storage battery or some other system for the storage of electricity will open entirely new vistas for the use of both wind and tides goes without saying. The present proposals are trying to utilize improvements in technology and the development of interconnection in order to overcome the inherent weakness of wind-power reliability.
New York Times, May 15, 1932, Section XX, p. 4