Underwater power

Researchers at NASA's Jet Propulsion Laboratory have proposed a new kind of underwater hydrokinetic energy transfer system they claim offers some tangible benefits over existing renewable energy systems.

In the new system, the flow of water current would cause turbine blades to rotate. The rotational speed of the turbine's rotor would then be increased through a gearbox, which would drive a high-pressure fluid pump. The high-pressure fluid would then be transported though flexible tubes to a larger pipe and then to an onshore hydroelectric power plant.

The system is the brainchild of Jack Jones, an engineer at NASA's Jet Propulsion Laboratory and Yi Chao, a JPL scientist.

'A major advantage of this design is that it eliminates all submerged electrical components, which are subject to corrosion,' said Jones.

In addition, other tidal turbine energy systems, such as the one now in operation in Manhattan's East River, transfer the power generated by the turbines to the surface through buried electrical cables.

These are expensive, hard to maintain, and can be dangerous, Jones said. Similar issues exist, he added, with two other types of hydrokinetic systems in use in the UK and planned for South Korea.

'Our hydrokinetic energy transfer system combines a simple, corrosion-resistant subsurface design with the least expensive electrical energy generation system onshore,' said Jones.

'The proposed system has another advantage,' he added. 'The pressurised hydraulic energy can be stored in an elevated onshore reservoir and can be used to generate electricity when it is needed to respond to energy demand. Most environmentally friendly energy systems produce power intermittently.'

Caltech, which operates JPL for NASA, holds the patent on the technology.