Getting energy from the sea is not new. A tide mill at Woodbridge, Suffolk, was first recorded in 1170 and the current mill on the same site continues to grind wheat flour. But large-scale electricity production has been elusive, although the La Rance Barrage in Brittany has been operating since 1966 and produces 600 GWh a year. The cost per unit is 1.8c per KWh compared with 2.5c for nuclear.
In the UK The huge Severn Barrage scheme has never got underway and promoters of the Wyre Barrage plan in Lancashire have been campaigning since 1991.
The other route is wave energy and again the UK has a lot of potential but the technical problems have proved difficult to overcome. Today the green energy company Ecotricity said a new system it is backing overcomes 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.
Their Searaser system from inventor Alvin Smith has successfully undergone tests in Plymouth University’s wave tank. Unlike other techniques it does not attempt to generate electricity at sea but wave operated pistons pump high pressure water to hydro-electric turbines on land. It could also pump water into reservoirs for use when needed.
Pumped storage is well established and the Ffestiniog power station in Wales has been working since 1963.
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.
He plans to have a full scale prototype working with 12 months.
Note: Ecotricity is our supplier at Ridgeway.