Wave Energy Research in Brazil Taking Off

This month the first serious experiment with wave energy officially begins in Brazil. The first wave energy plant in the country was installed in the northeast state of Ceará, more specifically in the port of Pecém, located 60km from the state capital Fortaleza and will be officially launched during the Rio+20 taking place in Rio de Janeiro.

With the Brazilian coastline being 8,000km long, scientists from COPPE/UFRJ, estimate that with wave energy plants up and down the coast the country could produce up to 87 gigawatts of which 20% could conceivably be converted in electricity, this would add up to 17% of the country´s total installed electrical energy capacity.

At this point though, concepts are still being tested in order to prove the viability and reliability of the project, which is financed by Eletrobrás, CNPq (Science and Technology Development Counsil) and Tracbel Engineering (through the Research and Development Program of the National Electrical Energy Agency) and also with support of the government of the state of Ceará.

The project calls for the construction of 20 modules, with a capacity of generating 500 KW. In this first stage two modules of the wave energy plant have already been installed. The two modules are composed of large mechanical arms. At the tip of each arm, there is a float in contact with the sea. As waves hit the floats, the structure (mechanical arms and floats) rise and lower. The continuous movement of the floats and arms activate hydraulic pumps, which propels sweet water enclosed in a closed circuit (with no contact with the environment), to circulate in a high pressure environment.

This sweet water under pressure goes to an accumulator, which in turn has water and air compressed in a hyperbaric chamber (which is the main component of the system). From the Hyperbaric chamber an extremely narrow conductor (like a venture channel), makes the water reach high pressures, which is then expelled in a water jet equivalent to a 500 meter waterfall similar to a big hydroelectric dam. This water jet moves a hydraulic turbine, which is connected to a generator, which in turn produces electric energy.

The project was first conceived by scientists at the COPPE wave lab at the UFRJ technology park in Rio de Janeiro. Around US$7,5 million have already been invested in the project during the last four years.

Claudio Paschoa