Learning form the Islay wave power plant

Abstract

In 1985, the wave power team at the Queen's University of Belfast commenced work on the prototype shoreline wave power plant on the Isle of Islay. A natural rock gully 4 m wide was selected in the south facing side of a headland to reduce the amount of construction and provide a partially sheltered environment in which to gain `sea experience' and conduct fundamental research, During 1988, a concrete plenum chamber 4 m wide, 9 m long and 9.7 m high was constructed and the pneumatic power output monitored for two years using a simple orifice. Finally, in May 1991, the plant was fully commissioned with the installation of the mechanical electrical plant and connection to the electrical distribution grid. The plant comprised a 1.2 m diameter biplane Wells turbine direct coupled to a 75 kW wound rotor induction motor operating as a generator above its synchronous speed of 1500 RPM. The design, construction and subsequent operation of the wave power plant has provided a significant insight into the feasibility of wave power conversion. The development of wave power plant poses a significant design challenge for civil, mechanical and electrical engineers. The plant must withstand the immense forces imposed during storms yet efficiently convert the slow cyclic motion of waves into a useful energy source such as electricity and do so at a mice competitive with other forms of generation. The step from the laboratory to prototype installations is considerable and was undoubtedly underestimated at the outset of the project. (5 pages)