Networks of Wind Energy Enthusiasts and the Development of the “Danish Concept” - Wind Power for the World: The Rise of Modern Wind Energy - page 141

communities in Denmark to vast wind farms at Altamont, Tehachapi,
and San Gorgonio passes in California, in the United States, where
many so-called “Danish clones” (from various companies but all
looking nearly identical to the naked eye) would be seen almost
littered across the hilly landscapes. This “Danish Concept” was born
out of the recently formed wind energy actor-network in western
Denmark which combined the smaller actor-networks of Tvind, NIVE
and the OVE as well as other groups not mentioned here, including
the Riisager wind turbine community and others.
Returning to Rossing's suggestion that NIVE build a wind
turbine to alleviate the shortage in supply of Riisager turbines,
Maegaard and his team revisited the UN report and their
experience with the Tvind turbine development. This report,
with its articles by Morrison, Juul and Hütter, would be used by
NIVE as their main source of guidance for designing their Gedser-
inspired turbine rated at 22 kW, similar to the popular Riisager
turbines. Just like the Tvind turbine, the design featured 3-blades
made of fibreglass material winding around the bolt holes at the
blade roots for a good connection to the hub. Maegaard, in particular,
had been somewhat involved with the Tvind wind turbine—he
had consulted with them on diferent aspects of the design and
accompanied Amdi Petersen to Sweden to acquire what would
be the Tvind drive train: An ASEA generator and gearbox that
was a spare from one of their industrial facilities. The Tvind team
decided to use a downwind turbine configuration because of the
advantage for the use of a more stable yaw system and the coning of
the blades away from the tower under thrust loads—both features
that the Tvind team believed would make the turbine more reliable
(Jensen, 2010). Maegaard, who had read in detail the 1961 UN
report from the conference on new energy sources, had noted in
an article on wind testing that the author Morrison had found that
tower shadow induced cyclic loading on the blades which could afect
the reliability of downwind turbines. He shared this with the Tvind
team though they had already committed to a downwind design
(Maegaard, 2010). For the NIVE design, however, an upwind
configuration was deemed preferable. Thus, the design featured
the basic characteristics of the Gedser and Riisager turbines with
the idea the incorporation of the new blade design based on the
Tvind turbine.