UK-based tidal energy technology developer Nautricity has announced it has deployed the first of its Contra Rotating Marine Turbine (CoRMaT) devices in Scottish waters.
Following an extensive round of investment and upscaling, the device is this week undergoing testing, along with the company’s patented HydroBuoy mooring system, at the European Marine Energy Centre, in Orkney.
Over the past 18 months, the Strathclyde University spin-out company has built its first commercial scale device which, with a rotor span of 10m, is significantly larger than early test models.
With the help of a £250,000 Smart Scotland grant from Scottish Enterprise, it has developed and patented the HydroBuoy station keeping technology, a tethered based mooring system that ensures the CoRMaT devices remain steady in strong currents. The buoy, shaped like the wing of an aircraft, combines displacement buoyancy with hydrodynamic lift to vary mooring tension proportionally, according to the strength of tidal speeds.
Cameron Johnstone, Nautricity’s co-founder and CEO, said testing the device at full-scale in real-life conditions was an important step forward that would produce valuable data to allow the company to proceed to full commercial deployment.
"Once we have demonstrated the technology here and shown that it can provide affordable electricity, we will then build out to multi-megawatt arrays at home and overseas. In order to be able to compete abroad in the future, it’s essential that we have a robust, indigenous market from which to launch our international business development," he said. "We believe we are doing all of the right things in developing lower cost, next-generation technology, through our progressive testing program and gathering the data to ensure that we are taking to market a product that works and can compete with other forms of energy generation."
CoRMaT has been designed as a lighter and more compact device than traditional tidal turbines, and can be tethered to the seabed and held in tension by a sub-surface float. The technology uses a novel, contra-rotating rotor system to cost-effectively harness tidal energy, said the company.
The turbines can be deployed in water depths of up to 500m and, because their closely spaced, contra-rotating rotors move in opposite directions, they remain steady in the face of strong tidal flows, allowing the device to "fly" from a simple tensioned mooring. This allows the device to maintain optimum alignment into the tidal flow as it varies its direction for maximum energy capture.
Image: The Contra Rotating Marine Turbine (CoRMaT) prior to deployment. Courtesy Nautricity
