We already produce green energy by harnessing the power of the wind and the sun – now we’re developing seamills using the power of the sea. This innovation is called Searaser and it gives us low cost energy on demand.

Invented by Devon engineer Alvin Smith, Searaser harnesses the almost constant power of ocean swells to create electricity on demand.

It’s such a simple design and we believe it’ll produce electricity cheaper than any other wave-power technology, or indeed any other type of renewable energy.

Potentially it could be cheaper than all existing sources of electricity – including gas, coal and nuclear – and it’s carbon free.

How it works

Most existing wave technologies generate electricity in the ocean environment. 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 in the water. It simply uses the almost constant motion of the ocean swell to drive seawater through an onshore turbine.

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 move up-and-down and the piston pumps pressurised seawater through pipes to an onshore turbine. This produces electricity.

Searaser units could also supply energy on-demand by pumping seawater into a coastal reservoir, with a hydropower turbine, solving renewable energy's problem of fluctuating output.

Reasons to switch

Dale Vince

"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."

Dale Vince, 2011