To scientists, it represents a tantalizing possibility: a new, plentiful and uninterrupted source of clean energy.
Florida Atlantic University researchers say the current could someday 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 Center of Excellence in Ocean Energy Technology. Using a $5 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 Oregon to Maine, 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 in the U.S. 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 the "Cuisinart effect": The 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 30 to 40 feet below the surface, because that's 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, which have run into opposition from environmentalists worried that the technology would spoil the ocean view, 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 is largely untested in the outdoors, so it is too soon to say what the environmental effects might be.
"We understand that there are environmental trade-offs, and we need to start looking to alternative energy and everything should be on the table," he said. "But what are the environmental consequences? We just don't know that yet."
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 field has been dealt some setbacks. An ocean test last year ended in disaster when its $2 million buoy off Oregon's coast sank to the sea floor. Similarly, a small test project using turbines powered by tidal currents in New York City's East River ran into trouble last year after turbine blades broke.
The Gulf Stream is about 30 miles 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.
