In 1993, professional diver Rauno Koivusaari was exploring a shipwreck in the Baltic. He was almost hit by a bulkhead door that was flapping slowly back and forth in powerful underwater waves. Most divers have noticed this phenomenon, but Rauno began to wonder if this bottom wave energy could be harnessed. It can – with WaveRoller.
In surface waves or swell, water particles roll in a circular motion. Coming in toward the shore, this energy is squeezed by the reducing depth. Below the surface swell, at a depth half of the length of the swell, the circular rolling motion becomes more elliptical, and at the sea bottom the water particles rock back and forth up to the breaker line.
WaveRoller captures this kinetic energy, using a specially designed bottom-mounted moving wing. The captured energy is converted to electricity using traditional technologies.