History of Danish Wind Power - Wind Power for the World: The Rise of Modern Wind Energy - page 70

Figure 3.30 The PTG turbine, built at Tvind in 1977 and using the same

blade design as the big Tvind turbine (Photo: Tvindkraft).

The Økær blades soon became the standard solution for
most of the new Danish wind turbines. Only four sets of the original
4.5 m blades were produced. They were used on wind turbines
constructed by electro-mechanic Svend Adolphsen and two other
members of the southern Jutland group. With its downwind rotor
and slender lattice tower stabilised by guy wires, the Adolphsen
turbine was in many ways inspired by Tvind's PTG turbine. It
was later modified and produced in Ulfborg under the name
“Kuriant” and was the first important commercial competitor to the
Riisager turbines.
The Adolphsen/Kuriant turbine in 1979 became the first
wind turbine to obtain the “system approval” from Risø, the new
national Danish test centre for wind turbines. It was established
in 1978, at the nuclear research centre at Risø. The placing of this
“ugly duckling” (to quote Andersen's famous fairytale) there amidst
some of the most active nuclear lobbyists was considered strange
by many on both sides of the intense nuclear debate. Although the