Nordic marine energy technology leader Minesto will conduct a pre-study for full-scale ocean trials of its power plant Deep Green that has demonstrated it is possible to harvest electricity from low-velocity currents.

The company received a funds injection from Vinnova, the Swedish innovation agency.

A quarter-scale prototype of Deep Green, also known as “the underwater kite”, is currently producing electricity in the waters off Strangford Lough, Northern Ireland. Deep Green is the only known marine power plant designed to produce electricity from low velocity tidal and ocean currents and as such significantly expands the global marine energy potential.

“Our technology is indeed different from other marine power plants. It has been a long fight to get to the point where we are but when you have what we have, it is worth it,” said Anders Jansson, CEO, Minesto. “This is a breakthrough for the entire renewable energy industry. We will produce renewable electricity with high reliability to a cost that will compete, or even be lower, than conventional energy sources.”

The sea trial in Northern Ireland measures longtime performance of Deep Green for valuable insights for the first full-scale installation of Deep Green, planned for 2015 and also possibly somewhere in the UK. The Deep Green demonstrator has a three-metre-long wing and is tethered to an offshore control room in Strangford Lough. A specifically equipped RIB boat enables safe and cost-effective offshore operations.

“Ocean currents are the hidden treasure of renewable energy sources,” said Anders Jansson. “With their almost continuous water flows they carry large amounts of renewable energy over the globe and with a high load factor compared to weather dependant sources like wind or solar power. The resource is predictable and feasible for providing base grid power, and has minimal environmental impact.”

“The challenge has been that the currents are too slow and the sites are too deep for most available marine power plants. Deep Green solves that problem. Minesto’s technology will contribute to make countries like the USA, Japan and Taiwan carbon neutral and independent energy producers, instead of hugely dependent on fossil based and
imported energy.”

Minesto explained the technology thus: Imagine you are standing on a beach flying a kite in the wind; you feel a strong force from the kite in the rope and notice that the kite flies fast, way faster than the wind is blowing. If you would attach a turbine to the kite and put it in the ocean, where water current flows instead of the wind blowing, you would have the concept of Deep Green, Minesto´s power plant. The secret behind Deep Green is that it reaches a speed 10 times higher than the water current, just like the kite flying faster than the wind. The speed has a cubic relationship to the power – a 10-times higher speed gives 1,000 times more power.”