'Rigid' vs. 'Soft' Wind Turbines
After 20 years of development, the common ‘rigid’ upwind turbines still need government subsidies and regulations to compete against electricity from coal.
The situation is worse offshore! Their installed cost per kW offshore is twice of that on land, due to the high costs of offshore foundations, installations, and power grids.
Efforts are being made to build larger wind turbines for offshore applications, 5 MW or larger, to lower the costs per kW installed. But, indications are: these efforts will not lower the costs by much!
Fundamentally, it is very difficult to reduce the costs of the ‘rigid’ upwind turbines for offshore applications! For the upwind turbine, the blades are upwind of the tower, and have to be ‘rigid’ and strong, such that they will not be bent back to hit the tower. In addition, the tower has to be ‘rigid’ and strong, such that the rotor can be turned into the wind with a yaw mechanism. Therefore, it takes a lot of material to manufacture the blades and tower of an upwind turbine, and makes it expensive and heavy! In addition, it also requires a very solid foundation, which becomes very expensive offshore! Furthermore, the offshore installation is also expensive!
Therefore, the ‘rigid’ upwind turbines and their extensions are unlikely to be cost-effective for offshore applications!
ecoPower’s Floating Wind Turbines are ‘soft’ wind turbines on submerged floating platforms. These 'soft' wind turbines include: (1) the vertical axis wind turbines that are ‘soft’ and unidirectional; and (2) the horizontal axis downwind turbines that are ‘soft’ and will follow and bend with the wind. These ‘soft’ wind turbines:
- will cost less to manufacture;
- can be placed on floating platforms to harness the strong wind at sea, over shallow as well as deep waters;
- can be towed to and anchored at the offshore windfarm sites, and avoid the high costs of offshore foundations and installation; and
- can be towed back to shipyards for repairs and maintenance,
- avoiding the danger and high costs of offshore repairs and maintenance.