A demo device for new approach of wave power generation

In cooperation with Chuanshiyu Machinery Co., Ltd., researchers with the CAS Institute of Electrical Engineering (IEE) have worked out a demonstration device that employs a novel approach to converting ocean wave energy into electricity.
Covering almost three-fourths of the earth's surface, oceans are rich in renewable energy sources, such as offshore wind energy, wave energy, ocean current energy, offshore solar energy. Among them, wave power receives top priority because of its high performance and enormous amount. However, the problem is that it's not easy to harness this energy and convert it into electricity in large magnitude. Thus, wave power station is facing several challenges. For instance, wave power is featured with low speed and powerful force, and the motion of forces is not in a single direction whereras most readily-available electric generators operate at higher speeds, and most readily-available turbines require a constant, steady flow. To solve the problem, a series of transformation steps are needed, which makes the whole system very complicated and drives its cost far beyond the acceptable market price.
Recently, an IEE group on magnetohydrodynamic (MHD) propulsion technology has come up with a new concept to deal with the problem. According to experts, MHD power technology supplies a new method to convert the thermal energy directly into electrical power. In a liquid metal MHD (LMMHD) power generation system, liquid metal with higher conductivity is used as the working fluid, and is driven to pass through an MHD channel in the presence of an intense magnetic field. An electromotive force (EMF) is induced between the channel walls.
Considering the slow-moving, high magnitude force of ocean waves and combining the characteristics of LMMHD generator, the IEE researchers have been working on LMMHD wave energy direct conversion (LMMHDWEDC) for the past year or so. The system can provide an excellent match to the mechanical impedance of the ocean wave. It is highly efficient and can be employed as a very compact device with very high power density. Scientists expect the system could be one of the best ways to directly convert ocean wave energy into electricity. Now, the researchers are making efforts to develop a 25kW sampling machine at their laboratory.