Underwater ‘kites’ set to power Northern Ireland homes by 2020

Belfast Telegraph: Underwater ‘kites’ set to power Northern Ireland homes by 2020

Underwater ‘sea kites’ could power a city the size of Belfast by 2020, according to the team behind a groundbreaking tidal energy device.

Tidal energy developer Minesto UK Ltd has just been awarded a Carbon Trust grant of up to £350,000 to install the first seagoing prototype of its innovative sea -kite technology ‘Deep Green’.

The device works like a kite tethered to the seabed, which flies through the sea currents carrying a turbine. The planned scheme will see a one-tenth size version of the Deep Green device put through its paces off the coast of Northern Ireland.

If the trials prove successful, Minesto — a spin-off of the Saab group — will deploy enough devices around the UK coastline to generate up to 530GWh a year by 2020, enough to power the annual electricity needs for households the size of the city of Belfast.

The turbine can operate in slower currents than any other known tidal energy technology, with the kite flying a figure of eight steered by a rudder, allowing it to effectively accelerate the speed of the water entering the turbine by up to 10 times. This allows more power to be generated, leading to a step-change reduction in the cost of tidal energy.

It could potentially unlock whole new areas of low-speed tidal stream around the coastline to produce electricity.

Minesto will work with the Global Maritime Alliance over the next 18 months to test the new tidal technology.

Minesto CEO Anders Jansson said: “Northern Ireland has the natural resources we need in terms of the depths of water and suitable geographic locations to install our technology.

“Northern Ireland also has a strong academia base and it is heavily involved with marine |renewable energy, which is a key developer in this industry. The Global Maritime Alliance is a valuable partner for us and we are excited about the opportunities that lie ahead.”

Benj Sykes, director of innovations at the Carbon Trust, said: “The UK boasts some of the best tidal resources in the world and we are focused on bringing down the cost of extracting that energy.

“Minesto’s Deep Green is a very exciting technology as it could provide a step change reduction in the cost of tidal energy.”

Background
The Deep Green kite has a 39-foot wingspan and 328-foot cable tethering it to the ocean floor — yet it is small compared to other tidal energy designs and can operate at greater depths, where currents are slower. When anchored, Deep Green can be steered into a figure of eight like a sport kite, its turbine capturing tidal energy at 10 times the speed of the actual stream velocity, according to Minesto, the Swedish developers of Deep Green.

[Whether this will ever get off the ground - or under the water - is debatable. It would require a no fishing zone - the lines attaching the kits would get caught - and as for animals....]