High tides, Low costs

According to the British company behind the new invention – Ecotricity – the new development will make clean energy in a even cheaper way then fossil fuel does nowadays.

Renewable energy has always faced the barrier of huge costs. The economics are still in favor of fossil fuels. However Ecotricity’s new project, the SeaRaser, could solve two of the biggest challenges facing renewable energy by providing a steady source of energy at low-cost. Invented by Devon Energy engineer Alvin Smith, the SeaRaser harnesses the constant power of ocean swells to create electricity on demand.

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 pressurized 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.

The company claimed the elegant solution will be operational by 2014. In February 2015 the tank testing is still going on. Like so many other promises of clean cheap energy, we need just to wait.

The company

A short demonstration