A significant number of wave and tidal technology concepts have been born in the university environment, though none are yet commercial.
The latest to come to Energy’s attention is a tidal device that lies at the heart of a Strathclyde University spin-out named Nautricity.
The firm claims that its turbine device is revolutionary and “will produce the world’s first domestically affordable electricity from tidal energy in the next 12 months”.
The device is CoRMaT, a patented twin-rotor system which, its developers claim, overcomes many of the problems which have made tidal energy production uneconomic until now.
While conventional tidal devices resemble wind turbines moored to the seabed, incurring enormous deployment and engineering costs, CoRMaT is a small, free-floating capsule, tethered to a surface float, which uses a novel, contra-rotating rotor system to harness tidal energy.
It can be deployed in water depths of up to 500m and, because its closely spaced rotors move in opposite directions, it remains steady in the face of strong tidal flows, avoiding the catastrophic stresses that single rotor devices have tended to suffer.
It is the contra-rotating nature of the device that ensures stability.
The famous Shackleton reconnaissance aircraft featured contra-rotating propellers.
According to Nautricity, a proof of concept version of CoRMaT has already successfully generated electricity and, later this year, a pre-commercialisation device will undergo further rigorous testing at the European Marine Energy Centre (EMEC) in Orkney.
The firm is among the companies selected by the Crown Estate to bid for the first round of licences to generate wave and tidal energy in the Pentland Firth.
Nautricity claims that, while natural gas, one of the most efficient energy sources, produces a megawatt/hour of electricity for around £48.90, and the cost of offshore wind generation is around £57.80 per mw/h.
There is no evidence that any tidal device is capable of generating electricity for less than several hundred pounds per mw/h.
“We anticipate that within the next year we will be capable of producing electricity that is competitive with offshore wind generation,” said David Pratt, co-founder of the spin-out.
He pointed out that first generation tidal devices were “nothing more than wind turbines in the sea”, and required very heavy foundations and engineering to take place on the seabed which means they had a high fixed cost.
“Our device is small, easier to handle and engineer and significantly simpler to deploy,” he added.
“We have lots of small units in the water compared with a few very big units.”
Nautricity launched in 2009 and has so far invested more than £2million in CoRMaT, with support from private equity investors.
Nautricity plans to begin rigorous testing in the autumn but could switch testing to Canada, the Mediterranean or Asia, depending on the level of support it receives from government and private sources.
“Several factors will determine where we test,” said Pratt, 52, a veteran of the oil and gas industry.
“It will ultimately come down to the kind of support and encouragement we get in any given site.
“We hope to capture a significant share of the world’s tidal generation market.
“In addition to some world class tidal resources off the Scottish coast, we have looked at sites in Canada, the United States, Chile, India, Korea and China.
“While Scotland was quick to realise the value of its tidal resources, other countries are catching up.
“Ideally, we’d like to have stockholdings in schemes in several countries within five years.”
Recommended for you
