Kite for low currents?

Back in July 2014, the Crown Estate, manager of the UK seabed, awarded an ‘Agreement for Lease’ for a commercial demonstration site for electricity production from tidal currents to marine energy company Minesto. Minesto will prepare consent application for the Deep Green Array site near Holyhead Island in Wales prior to the construction of a 10MW marine energy array in 2016, which, according to Minesto will supply electricity to approximately 8,000 households, and make Wales a world leader in marine energy.

The decision forms part of The Crown Estate’s UK-wide wave and tidal stream leasing round, which saw rights awarded for five new tidal stream sites across the UK, each with the potential to deliver a project of between 10 and 30 MW capacity. Minesto plans to start the installation of a 10MW marine energy array in 2016. The Welsh waters hold a potential of several 1000’s of MW, which makes Wales one of the most suitable places in the world for low velocity tidal energy.

The Carbon Trust expressed its support for The Crown Estate’s decision: “The Carbon Trust has provided technical and innovation support to Minesto since 2007. We are now excited to see they have achieved this Agreement for Lease since it opens the path to commercial roll-out of the technology. Minesto’s innovative technology has the potential to significantly expand the UK’s tidal resource, by unlocking lower velocity tidal flows, and lowering the cost of marine energy,” said David Aitken, Head of Incubation at The Carbon Trust.

Minesto’s tidal power plant, called Deep Green, looks like an underwater kite and is based on a fundamentally new principle for electricity generation from tidal and ocean currents. According to Minesto, Deep Green is the only known marine power plant to generate electricity from low velocity tidal currents, which greatly enhances the potential for marine energy.

Minesto will now further develop the project, which includes in depth environmental studies, detailed seabed mapping, cable routing and commercial activities. The Holyhead Deep site is located approximately seven kilometres from the shore where the water depth is 80-90 metres. The tidal currents are 1.5-2.5m/s. The area has been carefully selected to maintain separation from shipping lanes and to minimise the impact on other sea users.

By Jake Frith