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combined with a very slender, lexible tubular steel tower stabilized by many guy cables. The
majority of the turbine was assembled at the site near Bremerhaven, with less factory
assembly than most other machines.
The Growian HAWT was the only other large-scale turbine besides the KaMeWa to be
erected without a crane in this time period. The nacelle, with a central opening through which
the tower passed, was winched up the tower with rotor attached. The guy cables were tight-
ened, and the generator was then slid forward into place over the tower hatch, completing the
installation. The Growian was also the irst large-scale wind turbine to attempt variable-
speed operation. Unfortunately, the technology at the time could not support the number
and magnitude of the innovations undertaken. The Growian project encountered an
inordinate number of problems, including fatigue cracking of major components in the hub.
While it made signiicant contributions to the understanding of large wind turbines, it never
operated satisfactorily and was dismantled after only limited testing time.
A more successful turbine was the 370 kW, 48-m diameter
Monopteros
HAWT [Stahl
and Windheim 1987]. The Monopteros, constructed in 1981 near Bremerhaven, was the
irst large experiment in achieving very low solidities by utilizing a one-bladed rotor.
United Kingdom
Another European country investigating wind power on a large scale was the United
Kingdom. The Orkney Islands, with the interest of the North of Scotland Hydro Board,
became the major test site. The UK took a much slower and more deliberate approach than
most of the other countries and installed a 250-kW scale model, designated as the
MS-1
,
of its proposed large-scale system in 1982. The scale model was of rather rigid design with
a two-bladed downwind rotor of 20-m diameter. A privately developed prototype, the
300-
kW Howden
wind turbine, 22 m in diameter and of much more lexible tower construction,
was installed nearby. Thus two machines -- one of stiff design and one of “soft”, lexible
construction -- could be compared side-by-side. The megawatt-class prototype, the 3-MW
LS-1
, was developed at a deliberate pace. It evolved through several design conigurations,
ending as a two-bladed upwind turbine. Built by the
Wind Energy Group
(a consortium of
Taylor-Woodrow Construction, British Aerospace
, and
GEC
), it was installed in the
Orkneys, and testing commenced in 1987 [Page and Bedford 1987].
Canada
In Canada the technological route was different from other countries. Based on early
research there on Darrieus VAWTs, Canadian planners elected to concentrate future projects
in that direction. In addition to smaller systems for use in remote areas, a 230-kW experi-
mental Darrieus turbine of 24.4-m diameter was installed in 1977 at a Hydro-Quebec utility
facility on the Magdalen Islands in the Gulf of St. Lawrence. Basic testing of the turbine
proceeded satisfactorily, until a maintenance error caused the generator to be disconnected
without locking the rotor. While a Darrieus rotor has low starting torque, the unsecured
rotor started without load, oversped, and destroyed the turbine. This occurred, however,
after suficient positive results had been obtained to justify continuing the program. The
Magdalen Island
VAWT was rebuilt, and the development of two prototypes of the same
size, but up-rated to 500 kW, was initiated with
Indal Technologies, Inc
.
Installation of the
Eolé
VAWT (Fig. 3-36) was completed in early 1987 at Cap-Chat,
Quebec, near the banks of the St. Lawrence River [Richards 1987]. This giant machine was
64 m in diameter and was originally rated at 4 MW. It thus represented the irst
megawatt-
class Darrieus
turbine. Like a hydroelectric turbine, it had no gearbox. Instead, the rotor
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