Historical Development of the Windmill - Wind Turbine Technology: Fundamental Concepts of Wind Turbine Engineering - page 36

“Even now, it is not utterly chimerical to think of wind superseding coal in some
places for a very important part of its present duty - that of giving light. Indeed,
now that we have dynamos and Faure's accumulator, the little want to let the
thing be done is cheap windmills.” [Thomson 1881].

So, from the very beginning the cost of the wind machine was a major consideration. On the
proposed electric lighting by windmill-driven generators, Wolff predicted, “The application
of the windmill to this purpose will soon come actively into play when storage batteries have
been developed to a greater success than is attained at the present time.”
At that time, it had to be direct-current (DC) power not only for charging batteries but
also because of the varying speed on the windmill, which of course could also cause
continual variations in the power delivered (if it was available at all). But the demand was
there, and experimental work was carried out in several countries around the turn of the
century. Here, we describe two very different pioneering windmill-generators.
The irst, shown in the Frontispiece and
in Figure 1-18, is the Brush windmill , so-
named for its inventor and builder, Charles
F. Brush, a Cleveland, Ohio, industrialist in
the electrical ield [ Scientiic American 1890;
Spera 1977; Righter 1991]. In 1888, Brush
erected a windmill to supply 12 kW of DC
power for charging storage batteries on his
own large estate, mostly for 350 incandes-
cent lights. The coniguration he used was
the post mill. The wheel, with its 144
blades, was 17 m in diameter on a tower 18
m high, the latter supported by a central iron
post 36 cm in diameter extending 2.4 m into
a masonry foundation. To provide a steady
to relieve strain on the main post in extreme-
ly heavy winds, the tower had arms at the
four corners carrying casters at their bottom
ends which had a small clearance with a
concentric rail let into the foundation.
The upwind rotor was a solid-wheel
type, with an 18-m by 6-m tail vane and a
side vane to turn it out of the wind, like the
Wheeler Eclipse. The whole system operat-
ed automatically, and maintenance was said
to be minimal. It ran for 20 years until the
rotor was removed in 1908.
The Brush windmill was a landmark in
the history of the multivane type. In the irst
place, it was among the largest built, placing
it in the same category as the 18-m-diameter
machines used for lour milling and railroad
water-pumping. Second, it introduced the
high step-up ratio (50:1) to windmill trans-
missions, in this case by two belt-and-pulley
sets in tandem, to yield a full-load dynamo
speed of 500 rpm. Third, it was the irst
(and most ambitious) attempt to combine

Figure 1-18. The Brush windmill built in
1888 in Cleveland, Ohio. The irst use of a
windmill to generate electricity. [Scientiic
American 1890; Spera 1977; Righter 1991]