Pico plant

The Pico plant is an Oscillating Wave Column (OWC) system: waves enter in the "hydro-pneumatic chamber" (resembling a cave with entry below the waterline). The up-and down- movement of the water column inside the chamber makes air flow to and from the atmosphere, driving an air turbine. The turbine is symmetric and is driven indifferently in which direction the air flows.

Power take off system

The plant is equipped with a single horizontal axis Wells turbine with fixed pitch blades, with rotor diameter 2.3 m and rotational speed in the range 750-1500 rpms. The stator is formed by one row of fixed guide vanes on each side of the rotor in order to increase the aerodynamic performance of the turbine. An asynchronous generator of 400 kW of the wound rotor induction type was adopted, capable of operating over a relatively wide range of speeds. The electrical components in the plant are reduced to a minimum (generator and sensors), as a result from lessons learnt in the past. A power cable connects the generator to the power electronics placed in containers ca. 100m behind the plant. The internal system voltage of 380V is then transformed in two stages: first to 400V, and then to 15kV, thus sending an improved electricity in the nearby substation of the local utility. All electronic equipment was manufactured and installed by the National company Efacec. While the transformers and the grid connection equipment (Normafix) are off-the shelf, the generator and the converter where built particular for the Pico OWC. To date the performance of these components is evaluated very positively.