Ocean powers new wave of technology

Bendigo Advertiser
Wednesday 20/2/2008 Page: 20

JUST 24 kilometres off Florida's coast, the world's most powerful sustained ocean current the mighty Gulf Stream rushes by at more than 32 billion litres per second. And it never stops. To scientists, it represents a tantalising possibility: a new, plentiful and uninterrupted source of clean energy. Florida Atlantic University researchers say the current could some day be used to drive thousands of underwater turbines, produce as much energy as perhaps 10 nuclear plants and supply one-third of Florida's electricity.

A small test turbine is expected to be installed within months. "We can produce power 24/7," said Frederick Driscoll, director of the university's Centre of Excellence in Ocean Energy Technology. Using a $A5.55 million research grant from the state, the university is working to develop the technology in hopes that big energy and engineering companies will eventually build huge underwater arrays of turbines. From coast to coast in the United State, from Europe to Australia and beyond, researchers are looking to the sea currents, tides and waves for its infinite energy.

So far, there are no commercial-scale projects delivering electricity to the grid. Because the technology is still taking shape, it is too soon to say how much it might cost. But researchers hope to make it as cost-effective as fossil fuels. While the initial investment may be higher, the currents that drive the machinery are free. There are still many unknowns and risks. One fear is that spinning underwater blades could chop up fish and other creatures.

Researchers said the underwater turbines would pose little risk to passing ships. The equipment would be moored to the ocean floor, with the tops of the blades spinning 12 metres below the surface. because that is where the Gulf Stream flows fastest. But standard navigation equipment on ocean vessels could easily guide them around the turbine fields if their hulls reached that deep, researchers said.

And unlike offshore wind turbines the machinery would be invisible from the surface, with only a few buoys marking the fields. David White, of the Ocean Conservancy, said much of the technology was largely untested in the outdoors, so it was too soon to say what the environmental effects might be. The Federal Energy Regulatory Commission has issued 47 preliminary permits for ocean, wave and tidal energy projects, said spokeswoman Celeste Miller.

Most such permits grant rights just to study an area's energy-producing potential, not to build anything. The Gulf Stream is about 48 kilometres wide and shifts only slightly in its course, passing closer to Florida than to any other major land mass. "It's the best location in the world to harness ocean current power," Driscoll said.

Researchers on the West Coast, where the currents are not as powerful, are looking instead to waves to generate power. Canada-based Finavera Renewables has received a FERC license to test a wave energy project in Washington state. It will eventually include four buoys in a bay and generate enough power for up to 700 homes. The company hopes later to be the first in the US to operate a commercial-scale "wave farm," situated off Northern California.

Finavera spokesman Myke Clark said that wave energy was "definitely not the only answer" to the nation's power needs and was never going to be as cheap as coal. But it could be "part of the energy mix," and could be used to advantage for Third World countries, where entire towns have no connection to electrical grids.