Ecotricity takes to the water

Green energy company Ecotricity has announced it is to extend its wind and solar portfolio by adding the power of the sea to make green electricity.
The Stroud-based business will today announce it is developing a radical wave power device called Searaser – which it claims can address two of the biggest barriers to the deployment of renewable energy on the scale that Britain needs – cost and variable output.
Searaser is the brainchild of Devon engineer Alvin Smith and it harnesses the power of ocean swells to create electricity, Ecotricity says it hopes to install 200 of the devices within the next five years .
The announcement coincides with moves by the Department of Energy and Climate Change to make the South West of England the silicon valley of marine energy technology.
Ecotricity founder Dale Vince said: “Our vision is for Britain’s electricity needs to be met entirely from the big three renewable energy sources – the wind, the sun and the sea.
“Until now, the sea has been the least viable of those three energy sources and we believe that Searaser will change all of that. Indeed we believe Searaser has the potential to produce electricity at a lower cost than any other type energy, not just other forms of renewable energy but all ‘conventional’ forms of energy too.”
Inventor Alvin Smith said the main barrier to making wave-power efficient and therefore cost-effective – was resilience against the hostile ocean environment.
“Most existing wave technologies seek to generate electricity in the sea itself. But as we know water and electricity don’t mix – and seawater is particularly corrosive – so most other devices are very expensive to manufacture and maintain.
“But Searaser doesn’t generate the electricity out at sea. It simply uses the motion of the ocean swell to pump seawater through an onshore generator.”
Searaser pumps seawater using a vertical piston between two buoys – one on the surface of the water, the other suspended underwater and tethered to a weight on the seabed. As the ocean swell moves the buoys up-and-down the piston works like a bicycle pump to send volumes of pressurised seawater through a pipe to an onshore turbine to produce electricity.
This opens up the additional option for Searaser units to be used to supply energy on-demand. By pumping seawater into coastal storage reservoir, it can be released through a generator as required – thus making not just energy from the sea but energy that can be turned on and off as required.
Ecotricity claims such a system will go a long way to solving the problem of renewable energy’s naturally intermittent output on Britain’s electricity grid.
The company’s move into wave power comes as the Government and the Crown Estate make changes that they hope will encourage more development of wave-power in Britain.
Energy Minister Greg Barker said: “Marine Energy is a real priority for the coalition government It’s great news that Ecotricity are now making waves in marine power with their plans for Searaser.
“The UK leads the world in developing marine energy technology and it’s vital that the sector continues to bring forward innovative new technologies.
“Marine energy is becoming an increasingly attractive investment for businesses, not least because we are proposing more than a doubling of financial support to the sector through the ROCs scheme.”
Vince said Ecotricity’s investment will drive the next phase of SeaRasers’ development, by having a commercial scale Searaser in the Sea within 12 months and 200 Searasers around the British coastline within five 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.”