Curiosities in wind energy utilization 1

barnwindmill barnwindmill barnwindmill barnwindmill
If this barn windmill has operated effectively is not hand down. Perhaps a better aeration of the barn was achieved,
drying the stored hay or straw.
This " wind system " can be visited in:
Municipality Saalow, district Teltow Flaeming, Germany
Office at the Mellensee, main street 8, D - 15 838 Sperenberg,
Tel.: +49 33703 770-37, fax: +49 33703 -770-39


Whether this ' westernmill ' brings actually the double performance is uncertain.
One of the two rotors is always aligned in the wrong winddirection, a little bit 'falsely ', because a windrotor-system operates always in a full turbulent boundary layer. And if you think on oscillation problems! . . .
In any case the most economic concept is: not several rotors on a mast or a tower, only one rotor on the top of one tower.

Lagerwey-multirotor Nevertheless, once again, the fruitless attempt is made. The company Lagerwey set up its "Four in one"-system, the Quadro-mill, in the proximity of Rotterdam, nearby Maasvlakte. The total mass of the system is roughly 400 tons. But please make the following calculation: take these 400 tons and build up a modern 1.5 MW windconverter (for example, the ENERCON E-66). This machine weighs roughly 250 tons, with 66 m diameter and 65 m tower and with 34.421 m2 circular area. The harvested energy quantities, at the same site, show quite clearly where" the journey of wind energy sytems" goes to: E-66 approx. 3.5 millions kwh/a, Lagerwey Quadro 0.6 millions a kwh/a.
More than in all other fields of the technique counts in the area of wind enery utilization the relation: expenditure to earnings to be" economically ".

The fact that the multiple rotor is really no idea of "modern times " shows a proposal, made by Fisher (Denmark) in 1974 and another, made by professor Heronemus (USA).
Fisher-tower Heronemus-tower Jean Fisher suggested as aesthet and architect a building with a multiplicity of Darrieus rotors.
Professor W.E. Heronemus, University of Massachusetts, years ago, wanted to establish many 20 KW of horizontal axis rotors on a tower with a large turntable at the bottom for wind direction control.
The same system he wants to erect offshore, like a buoy tumbling in the surf. Both suggestions were never carried out.

Wagner-Rotor, V-Darrieus-Typ At the beginning of the eighties a fixed idea of Dr.Wagner, from the island Sylt, Germany, attracted attention. He build a V-Darrieus-Rotor and installed this device on the deck of an old fishing-boat. He wanted to become known and rich with this floating and mobile offshore-wind system.
He planned a whole type-family of wind energy converters from 3 MW (80 m rotorblade length/2 m rotorblade depth at the blade tip/6 m rototblade depth at the blade root (hubposition)), 5 MW (100/2,4/8 m), 10 MW (140/3,6/10 m) up to 100 MW (370/9,2/30 m).

doerner@ifb.uni since 3 August 1998