Energy is not in short supply - the sun provides the Earth with 10 000 times as much energy as society consumes. It is the means of transforming this energy into energy we can exploit that is missing. Some of the solar energy is to be found in waves on the sea and a number of ideas are being tested using various technologies and systems. One example is Waves4Power; following successful sea trials the company is now taking the next step towards commercialisation. A robust solution, combined with long experience and great patience can make Waves4Power into one of the companies that can show us that wave power will play an important role in future sustainable energy systems.
Waves, the most energy dense form of solar energy
The energy of ocean waves is the most concentrated form of solar power. When sun heat the surface of the earth, air motion – wind – iscreated. The wind blowing across the ocean creates waves with very high energy density, almost a thousand times denser than wind. With 2/3 of the earth surface covered by water it only makes sense to capture the enormous free energy resource hidden in the waves.
Waves4Power AB is a Swedish development company with the charter to commercialize ocean energy by generating electricity in a cost efficient way using the proprietary WaveEL-Buoy. The development of the WaveEL-Buoy started in 2008 and by Spring/Summer 2010 a full scale prototype buoy was successfully tested for five months in the ocean off the Swedish west coast. Waves4Power is now moving into its second phase in the commercialization process, with the aim to build several buoys in 2011 and 2012 to form a Wave Power Farm that will be connected to the power grid in a community on the Swedish west coast.
The WaveEL-Buoy is a point absorber that is slack moored with no rigid connection to the ocean floor. The system consists of four main components:
- A buoy with a long acceleration tube – open in both ends – that stretches deep down below the buoy.
- A hydraulic power take-off system with a water piston placed in the acceleration tube.
- A mooring system that keeps the buoy on station without interfering with the buoy’s vertical motion.
- A transmission system that brings the electric power from the buoy to the power grid on shore.
The working principle is based on a reacting two body system were the buoy/acceleration tube’s vertical motion in the waves, causes the water column in the acceleration tube to oscillate up and down and the hydraulically dampened water piston to move with the water column acting as a hydraulic pump. A hydraulic motor connected to a generator converts the hydraulic oil flow to electricity.
Waves4Power cooperates closely with Frog Construction & Diving, Reinertsen Sverige and Göteborg Energi, which helped finance the first development phase through a grant.
Membership in Cleantech Inn Sweden opens new opportunities for Waves4Power to collaborate with companies with complimentary resources and interests and will help to open doors to access funding from both public and private sources.
Göran Fredrikson, Cofounder/Director
Waves4Power
Waves, the most energy dense form of solar energy
