BRAZIL:
Clean Energy Effort Rides Ocean Waves

Mario Osava*


RIO DE JANEIRO,  (Tierramérica) - Surfers are not the only ones who will be enjoying the massive power of the Atlantic Ocean's waves on the Brazilian coast. For the first time in the Americas, ocean waves are to be used to generate electricity -- enough for 200 families in the northeastern state of Ceará.

If all goes as planned, by the end of 2006 Brazil will debut the first wave-powered electrical plant in the western hemisphere, churning out a potential of 500 kilowatts.

The project is being developed by the COPPE engineering graduate programme at Rio de Janeiro Federal University, which has already built a small-scale demonstration model at its Submarine Technology Laboratory (LTS).

Construction of the full-size plant based on this renewable source of energy became feasible with an agreement signed earlier this month by the Ceará state government and Electrobrás, the national electric company.

”Ceará has the ideal conditions because the Trade Winds blow there, generating good, regular wave action,” Segen Estefen, coordinator of the project and head of LTS, told Tierramérica.

With some innovative technology, unlike wave power projects being developed in other countries, this alternative will be competitive, at a cost equivalent to the energy generated by the hydroelectric dams already operating in Brazil and 30 percent cheaper than wind energy, said Estefen.

The new project is to be built on Brazil's Atlantic coast, near 70 percent of the 174 million people in the country. The location helps save on the costs of transmission lines, which is what drives up rates for electricity coming from hydroelectric dams located far from consumers.

With 8,500 km of coastline, Brazil has enormous wave-power potential. Estefen estimates that it could contribute 15 percent of the electricity consumed in the country ”within 10 to 15 years if the government decides to promote programmes” in that direction.

The energy potential of all of the world's oceans is estimated at one or two terawatts (one terawatt is a trillion watts), enough to cover the energy demands of the global population, but most of that potential is not economically feasible to tap into.

Using 10 to 20 percent of it ”would be colossal,” commented Estefen, adding that alternative sources ”will always be complementary.”

The wave-powered plant designed by his team uses floats that, with the movement of the waves, activate a hydraulic pump which injects water into a hyperbaric chamber. This chamber was originally developed to test equipment for undersea exploration and deep-water oil drilling, and withstands extremely high pressure -- as in conditions at depths of 5,000 meters.

The hyperbaric chamber releases high-pressure jets of water that move the turbines which convert their energy into electricity.

This invention takes advantage of existing technologies, especially those developed for ocean-bottom oil extraction, an area where Brazil has made major advances.

The equipment is available and all of it can be produced in this country, keeping the project's costs down, says Estefen.

Other countries that are further along in wave energy development, like Britain, with its two plants in operation and five in development, utilise oscillating columns of water to generate electricity.

A giant tube is inverted into the ocean, and the rising water level pushes up the air inside the tube, moving a turbine. And the reverse occurs when the water level decreases, as the wave diminishes, also generating electricity, explained Eliab Ricarte, whose doctorate research contributed to the Brazilian wave energy project.

But the British technology involves great variations in output, with the rotation of the turbine doubling from one moment to the next, depending on the size of the wave and its movement. The Brazilian model, meanwhile, has the advantage of regularity, said Estefen.

In Denmark, experts are developing what has been dubbed the ”Wave Dragon”, technology for a larger energy generating plant capable of putting out four megawatts. It requires high waves, out at sea, in order to move the turbines with the same force. Estefen noted that it would not be operable in summer because of the lack of large waves.

Australia and Japan are also developing technologies to take advantage of wave energy, and in the developing world, Brazil is joined by India and China. But for now, the norm is small prototypes, with a capacity of up to one megawatt.

An effective contribution to commercial energy production remains a goal for the future, say the Brazilian experts.

Interest in this alternative source has intensified in the past five years due to the priority given to climate change issues on the international agenda, according to the World Energy Council. There is greater emphasis on developing alternatives to fossil fuel-based energy, which produces climate changing greenhouse gases.

Other contributing factors include the debate surrounding the Kyoto Protocol, which has not entered into force but sets goals for reducing greenhouse gas emissions, as well as the rise in petroleum prices.

Britain has set the standard with its 1999 decision to invest in ocean wave energy.

The Japanese model is known as ”Mighty Whale” and entails a column of oscillating water in a ship in the open sea, taking advantage of the greater energy potential farther from the coast. It was watching a video about that experiment that Ricarte decided to dedicate his doctoral thesis to ocean wave energy in Brazil.

The Brazilian approach is to build relatively small installations, with a capacity of one to 30 megawatts, keeping the already low environmental impact to a minimum.

There is also the possibility of ”shared use”, such as utilising the energy plants to protect the coast, reducing erosion. And in some cases the ocean bottom could be altered to obtain larger waves, and that could benefit surfers, says Ricarte.

(* Mario Osava is an IPS correspondent. Originally published Feb. 7 by Latin American newspapers that are part of the Tierramérica network. Tierramérica is a specialised news service produced by IPS with the backing of the United Nations Development Programme and the United Nations Environment Programme.)