Wave Dragon

The Wave Dragon is a floating offshore wave energy converter, invented by the Danish engineer Erik Friis-Madsen.

In the current research and development project a scale 1:4.5 model of the Wave Dragon has been designed, constructed and deployed in Nissum Bredning, Denmark.

The duration of the project is approximately 3 years (until summer 2005) where a number of issues that cannot be thoroughly tested in a wave tank, will become subject of measurements and analyses. The model is equipped with 7 turbines and comprehensive measurement instruments.

If the outcome of the project is as expected, a first generation full-scale Wave Dragon model will be deployed in 2006, presumably 20-30 km off shore in the North Sea.

The project is supported by the Danish Energy Authority, the European Commission and Elkraft System's PSO funding.

Further information:

Please also visit the new homepage for the Wave Dragon 1:4.5 project.


The Wave Dragon is a floating offshore wave energy converter of the run-up type. The waves are focused by two wave reflectors, leading to a patented doubly curved ramp. The waves run up the ramp and into the reservoir, and the resulting pressure height is utilised for power production through a number of propeller turbines.
The basic layout and functioning of the Wave Dragon is illustrated by the figure below.
Click to enlarge Wave Dragon illustration
The Wave Dragon is developed and patented by Erik Friis-Madsen from the consulting engineering company Löwenmark, F.R.I. From the initial perception in 1987 the concept has been continually developed and tested.

In 1998-99 a scale 1:50 model was tested for survivability and hydraulic performance in a wave basin at the Technical University in Aalborg, partly financed by the Danish Wave Energy program.

In 1999-2000 an EU Joule Craft project was carried out, investigating hydraulic performance, turbine development and operation strategy, regulation strategy, power generation and grid connection, structural layout and feasibility. This project had a total budget of 1 mill. EUR, of which half was sponsored by the industrial participants:

  • Löwenmark F.R.I - Consulting Engineering Denmark - Inventor and participating in most tasks.
  • Balslev - Consulting Engineering Denmark - Responsible for electrical, and control-, surveillance- and regulation equipment.
  • Eltra - Power distribution Denmark - responsible for grid connection.
  • Kössler - Turbine manufacturer Austria - Turbine design, regulation and feasibility
  • Belt Electric - Generator equipment Denmark - power generation.

The scientific participants were:
  • EMU - project coordination and regulation strategy.
  • Armstrong Technology - Naval design U.K. - Structural layout and mooring.
  • Veteran Kraft - Turbine designer Sweden - Turbine design and regulation.
  • Aalborg University Denmark - Model tests, regulation strategy
  • University College Cork Ireland - Model tests and mathematical modelling.
  • Technical University Munich Germany - Turbine design and regulation.

The Wave Dragon showed good survivability in harsh wave conditions, even in case of malfunction.

Efficiency in power production was in model test found to 9-10%.
The target for the full scale prototype efficiency is 16%

The Wave Dragon will use a number of relatively small propeller turbines with fixed runners and guide vanes, utilising variable speed.

The commercial exploitation of the Wave Dragon will be handled by the partners involved in the development process, currently on a consortium basis.
When reaching a state of technological development calling for actual commercial exploitation, a development company will be established, allowing for financial investors to enter the company, and the RTD costs to be capitalized.

A full-scale 1st generation prototype is expected to have the following key data, when deployed in a wave climate with an average power of 24 kW/m:

Production price: 0.1-0.12 Euro/kWh
Fixed costs: 13.5 mill Euro
Weight: 18,000 tonnes
Width: approximately 260 meters between the wave reflectors.
Location: offshore, more than 20 m depth
Mooring: slack-moored
Installed effect per unit: 4 MW
Number of units per location: 30-200
Turbines: Propeller turbines
Annual production: 9,9 GWh in a wave climate of 24 kW/m

For further information, we recommend the following papers and reports

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