Environmental Engineering Reference
In-Depth Information
of even longer blades of 9 m, 10 m, 11 m and 12 m. Development
and testing stayed in its native area in Sparkær, where Erik Grove-
Nielsen had built a testing centre.
Altenergy's 12 m blade from about 1986 was the end of it.
Only a few 12 m blades were made. With the shutting down of the
American market the conditions in the windmill industry were
extremely difficult; all wind turbine manufacturing, apart from
Bonus, went into financial problems. However, in the meantime other
blade producers had in due time entered the strongly expanding
market. While AeroStar during the Californian boom sufered from
quality management of their products the newcomers organised
efective quality control and took over.
7.12.1
LM: The Blade Giant
LM
in Lunderskov made a very discrete entry as blade supplier
around 1982. Their starting point was many years' experience
within fibreglass as an industrial product—a background which was
to prove just as important as the knowledge of wind energy. They
started cautiously with 7.5 m and 8 m blades, which were largely
compatible with the then dominating blade product. The first LM
blades for 55 kW and 75 kW wind turbines appear on Wind Matic
that changed from Riisager type blades. At the time, a 3.5 m LM
blade could also be found on the Wind Matic 7.5 kW. LM adapted
to the needs of their customers and also supplied diferent sizes
of blade shells for their Riisager clones to Sonebjerg Maskinfabrik.
LM made steady progress. The blades grew in size and in 1986
they delivered 11 m blades for 150 kW wind turbines. One can
find them on wind turbines from Bonus, Vind-Syssel and others.
LM's blades at the time were designed to turn anti-clockwise. They
had air brakes of the spoiler type at the front edge of the blade,
whereas other fibreglass blades turned clockwise and had tip
brakes like the Gedser windmill.
LM finally succumbed. The spoilers disappeared and in the
long run the public could not tolerate that wind turbines rotated
in diferent directions. So from 1988, LM blades turned clockwise,
which from a historical perspective, really was the wrong way.
The wooden blades of the past turned to the left because the
natural twist of the wood was determined by the sun passing over
the sky from east to west, in the Northern Hemisphere at least.
Search WWH ::
Custom Search