Testing of a gyroscopic Wave Energy System

The extraction of energy from ocean waves has been investigated in Europe since the 1970s. Several devices have been proposed and a few of them have been built full scale and deployed to the ocean. Actually there is not a kind of device that is accepted as the most suitable to exploit wave power. One of the practical problems to be solved in a Wave Energy Converter (WEC) is the durability in the harsh marine environment and the capability to withstand in extreme weather conditions. The durability could be critical if parts of the converter, such as turbine rotors or auxiliary floats, are needed to move or to react while exposed to seawater and spray. One method to solve the problem is to use a WEC composed just by one sealed floating body carrying a gyroscope. The incident waves activate the precession motion of the gyroscope, the output power is produced by damping the precession motion. The whole system operates in the clean environment on the float. In this paper the design and the tests of an ISWEC (Inertial Sea Wave Energy Converter) are presented. The tests are carried out both by a purposely designed test bench in the laboratory and in a wave tank.