This plant consists of a hollow reinforced concrete structure – pneumatic chamber – above the water free surface that communicates with the sea and the incident waves by a submerged opening in its front wall, and with the atmosphere by a fibre duct (1) with an air Turbine (2+4).
The incident waves cause vertical oscillation of the water column inside the chamber, which in turn causes alternate air flow to and from the atmosphere, driving the turbine and the generator attached to it. The electricity is fed into the local grid of EDA (Regional Utility) at the Cachorro grid connection point. An important factor in designing this kind of plants is the dimensions of the pneumatic chamber, in order to provide resonance with the incident sea state.
Due to the dimension and particular working environment for this type of turbines, a series of technical difficulties have limited the normal functioning of the Plant making the presence of a technical team at site very important for the learning process. While initial tests between 2005 and 2006 yielded a total production of around 1 MWh, almost the same amount of energy has been produced in only one 48-hours-test in May 2009.
COMPONENTS OF THE PLANT
The oscillating water column (2) inside the chamber forces air alternately to and from the atmosphere (3), via a Wells turbine with symmetric blades (7).
To avoid over-pressure and stall conditions, a relief valve (4) exists which can be opened from 0% to 100%, according to the incident sea-state. The generator (8) linked to the turbine transforms the rotational force into electrical power, which is sent to the local EDA grid, via a converter and two transformers located in the containers 100 m above the plant.
