Scientists in Madrid say they have designed a device which could harness the power of ocean currents in deeper water and potentially at a cheaper cost than existing technology.

Researchers at Madrid’s Polytechnic University (UPM) conducted sea trials of their remote controlled prototype which can anchor underwater at about 40 metres with the help of a buoy and can be made to float to the top for repairs. First generation underwater ocean devices were limited to 30-35 metres, say the researchers.

Made from stainless steel it has a cylindrical central body and three external parts which resemble rockets attached by arms. These arms turn like a rotor in ocean currents to power the generator. The device is built at a tenth of the size of an industrial unit which could generate 1MW of electricity.

The university said test results were “very successful” and showed the prototype hit their objectives of “reducing costs of construction, installation and maintenance”.