In an assessment of the potential energy that could be generated by ocean currents, the Department of the Interior noted that capturing just .1 percent of the Gulf Stream's energy could meet 35 percent of Florida's annual electricity needs. Put another way, there's 21,000 times more energy in the Gulf Stream than in Niagara Falls.
The challenge is getting turbines into the seabed or on underwater platforms and keeping them in working order. One idea, from Darris White of Embry-Riddle Aeronautical University in Florida, forgoes the fixation on keeping the turbines in place. White is working on autonomous turbines that would act like schools of fish, traveling with the current and communicating with one another via sensors.