Innovation provider

Wave Star A/S



The fundamental idea behind Wave Star patented in 2001 is the wave energy system comprising floats on rocker arms ending in rocker pipes . It is attached to concrete pillars and allow the force to be transferred to a electric generator.
The patent was bought by Wave Star in 2004. The company had been established the year before by a former owner and director who believed in the invention and in the potential in wave energy as a future resource. Soon after the Clausen family of Danfoss joined as investors and the own the company solely today.
The invention is now protected by 4 patent families from 2001, 2004, 2004, 2006.
A scale 1:40 test machine was build together with Aalborg University in 2004 and tested in indoor tanks in 2004-2005. Wave Star and Aalborg University is still today working closely together.
After testing the concept at the university Wave Star began the construction the scale 1:10 test machine for the sea in 2005. It was installed in a fjord, Nissum Bredning, in the Northern Jutland in 2006. It produces power and is still operating today where it is used for testing of e.g. materials and control systems.
The 1:10 machine is 24 meters long and the 40 floats has a diameter of 1 m. It has been through several storms without damage which proves the storm protection system.
The purpose of the small scale test machine is also verification of the concept providing data and power curves.
A new hydraulic system was installed on the 1:10 machine to test individual regulation of each floater. This method was an important improvement and implemented on the next machine.
The design of the latest machine, the scale 1:2 test section, began in 2007. It was constructed in 2008-2009 and installed in September 2009 in North Sea at Hanstholm. It is a shortened version of the complete 500 kW machine with only two floats. It is situated 300 meters from the shore at a water depth of 7 meters. It is 40 meters long with 2 floats of a diameter of 5 meters.
It has been operating since January 2010 and is producing power in a limited quantity according to the reduced number of floats. The machine will be there until at least 2013 for testing of materials and systems.
The main transformation from the original design is the pipe instead of the lattice structure. This gives more stability to the structure and provides more space for the technical equipment.
Besides that the most important is the scaling which requires modifications. Examples are a change of the jacking system to be able to lift up the huge construction and new algorithms and control systems.   
The most important work at the current stage is to improve the harvesting of energy as well as the PTO system (Power Take Off). 


 The Wave Star concept is unique due to:
  • Simple and reliable storm protection where the floats will be lifted above the passing large waves
  • All critical electronic and mechanical parts are out of the seawater and thus have limited structural, wear and corrosion exposure
  • The unit design is based on standard components and proven offshore technologies developed by the oil and gas exploration and production
  • Easy to maintain since all components are basically at sea level

Innovative aspects (ecologic, social and economic)

  • Renewable energy production up to 6 MW or larger per plant, scalable from the current 1/10 and 1/2 size test units in operation
  • Simple and reliable storm protection where the floats will be lifted above the passing large waves
  • The energy production by WS units will complement energy produced in off-shore wind parks
  • It is environmentally neutral in the sea and has a much lower visual profile or impact than off-shore wind turbines

Application examples


Current stage of development

Already on the market

Intellectual Property Rights

Patent granted

Country of origin


Country of application



National Contact Point

René Grøn
Teknologisk Institut (DTI), Center for Produktion
2630 Taastrup
Tel: +45 7220 2937