‘Links of a sausage’ convert wave energy into electricity.In previous Maui Weekly articles on ocean energy, we compared an oscillating water column (OWC) device to a natural blowhole. The Oceanlinx wave energy machines proposed for Pa‘uwela Point along Maui’s North Shore will use OWC technology.
There are, however, a great number of ways that innovative companies propose to tap into the endless energy of the ocean. In this article, we’ll begin to examine some of the other concepts.
One of the world’s leaders in ocean energy is a Scottish company called Pelamis Wave Power Ltd. The Pelamis wave energy device consists of several large, long cylinders linked together, rather like links of a sausage. The machine looks something like a sea snake, hence its name, which is taken from Greek mythology. Before Sept. 2007, the company was named Ocean Power Delivery.
As this “sea snake” noses into waves, its articulated body bends up and down and side to side as the waves pass. Hydraulic connections between the segments pump pressurized fluid through hydraulic motors, driving electrical generators and producing electricity. Test machines have operated at the European Marine Energy Center (EMEC) in Orkney, Scotland, providing electricity to the national grid. Pelamis is presently commissioning three 750-kW machines in the ocean off Portugal, and has agreements for additional machines at the Portuguese site, in addition to Orkney and Cornwall in the United Kingdom.
The three Pelamis machines commissioned at a site about three miles off the coast of northern Portugal constitute the world’s first, multi-unit wave farm and also the world’s first commercial order for wave energy converters.
A representative of Pelamis has visited Hawai‘i and discussed potential future projects with government agencies, electrical utilities and other stakeholders. However, there are no firm project agreements in the works for Hawai‘i at this time.
In partnership with the state’s energy office, the Maui Weekly provides this feature to help Valley Isle homeowners reduce their utility bills and increase their environmental awareness.