Conceptual study of tidal stream and ocean current turbine with floating axis configuration

Cost of energy in utilizing the tidal stream and ocean current is considered to be higher than those of other renewable energy resources like wind. It is mainly due to the cost of device and maintenance in marine environment. The authors propose a tilted cross flow type turbine for electricity generation in water stream. Although the design is similar to vertical axis water turbine, the rotating axis tilts according to the water current. Since the design requires less structural strength in support system, we can reduce the weight of total system and utilize wider depth range of water stream with relatively small device size.