27 October 2014
Generating electricity from wave power in Britain took a step closer to reality after green energy company Ecotricity’s innovative device – Searaser – successfully completed first stage testing at Plymouth University’s CoastLAB wave tank.
The brainchild of British inventor Alvin Smith, Searaser is designed to overcome two of the biggest hurdles in the deployment of renewable energy on a scale that fulfils Britain’s future electricity needs – cost and variable output.
Ecotricity and the Searaser team have spent the past 18 months optimising the design of the device and modelling outputs in real word conditions around the coast of Britain - with the assistance of one of the world’s leading marine energy consultants, DNV GL Group (formerly Garrad Hasan).
Mr Smith said the determining factor in making wave power efficient, and therefore cost-effective, was resilience: “We’ve just completed wave tank testing at Plymouth University to validate the extensive computer modelling we’ve been undertaking.”
“We’ve put Searaser through the most extreme testing regime at Plymouth’s CoastLAB and it’s passed every challenge.”
Unlike other marine energy technologies, Searaser won’t generate electricity out at sea but will simply use the motion of the ocean swell to pump high pressure seawater ashore, where it will be used to make electricity. The motion of the waves drives a piston between two buoys – one on the surface of the water, the other suspended underwater and tethered to a weight on the seabed.
As waves move past, the surface buoy moves the piston up-and-down, pumping volumes of pressurised seawater through a pipe to an onshore hydropower turbine to produce electricity.
These ‘Seamills’ could be used to pump seawater into coastal reservoirs, from where it can be released at any time of the day or night, to make renewable electricity on demand.
Ecotricity founder Dale Vince said: “Our vision is for Britain’s electricity needs to be met entirely from our big three renewable energy sources – the Wind, the Sun and the Sea.
“Out of these three energy sources, generating electricity from the sea is by far the most difficult due to the hostile ocean environment – it’s also the least advanced of the three technologies but it has enormous potential.
“We believe these Seamills have the potential to produce a significant amount of the electricity that Britain needs, from a clean indigenous source and in a more controllable manner than currently possible.”
Vince said Ecotricity hoped to have a full scale prototype in the ocean in the next 12 months or so - and to be producing electricity from the first commercial arrays of Seamills within a few years.
Vince said: “The potential is enormous. This is a British invention that could transform the energy market not just here in Britain but around the world. Our plan is to develop the technology and make them here in Britain, bringing green jobs as well as green energy to our country.”