Norway’s energy company, Statoil-Hydor, has launched a floating wind turbine, rated at 2.3 MW and claimed as the world’s first of its kind. In June, after assembly near Stavanger, the 65-meter-tall Hywind device with 80-m-dia blades was towed 10 km off Karmøy island for two years’ testing, beginning on Sept. 8. The 5,300-tonne unit, including a ballasted and anchored 100-m-deep supporting steel cylinder, is part of a $55-million research and development project. Photo: Statoil-Hydro
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.