Underwater kites that look like the Starship Enterprise will harness 'liquid breezes' to supply the world with electricity

• The futuristic devices look like the fictional spaceship in Star Trek but could play a part in providing much needed energy to the world's growing population
• 'Unseen under the waves, winding along coastlines and streaming through underwater channels, there are countless ocean currents and tidal flows that bristle with kinetic energy,' he said. 
• 'And just as wind turbines can convert moving air into electricity, there is the potential to transform these virtually untapped liquid 'breezes' into vast amounts of power.

'For example, it has been estimated that the potential power from the Florida Current, which flows from the Gulf of Mexico into the Atlantic Ocean, is 20 gigawatts—equivalent to about 10 nuclear power plants.'

The project has recently been given a three-year, $300,000 grant from the National Science Foundation (NSF) to explore ways to harness ocean currents and tidal flows.

HOW DO WATER KITES WORK?

Energy from a tidal stream is converted into electricity using a kite with a turbine.

The kite assembly, consisting of a wing and turbine, is attached by a tether to a fixed point on the ocean bed.

As water flows over the hydrodynamic wing, a lift force is generated which allows the device to move smoothly through the water and for the turbine to rotate hence generating electricity.

Dr David Olinger of Worcester Polytechnic Institutesaid: 'It has been estimated that the potential power from the Florida Current, which flows from the Gulf of Mexico into the Atlantic Ocean, is 20 gigawatts—equivalent to about 10 nuclear power plants.'

'Instead of moving air, you have moving water and the kites have rigid wings,' Olinger said, 'But the same physical principles apply.'

One way to generate power with underwater kites is to have an electric generator attached to the kite, which would be tethered to a floating platform.

Using computational models, Olinger and his team will virtually test possible designs for undersea kites and explore methods for tethering them to floating platforms similar to those used for oil and gas rigs. 

In the final stage of the research, they will build scale models of the kites and test them in a water tank at WPI and at the Alden Research Laboratory, a renowned hydraulics research facility where the kites will be'flown' in large water flumes.

Another firm, Minesto, is also experimenting with the technology.

The tidal energy device developed by Minesto, named Deep Green, converts energy from tidal stream flows into electricity using a kite with a turbine.

'The kite assembly, consisting of a wing and turbine, is attached by a tether to a fixed point on the ocean bed,' the firm says.