Tordenskiold

The prototype - Tordenskiold

Completion of the second test


Tordenskiold is back in Frederikshavn after the second offshore test phase near the Hirsholm islands. For a total of 14 months, data has been collected regarding the plant's capacity and efficiency in all kinds of weather, from small waves to storms and hurricanes.

NIRAS has analyzed and compared the offshore data with previous pool tests data. Later in the year, 2020, a report will be published to form the basis for further development of Tordenskiold and the plant's PTO system, as well as to determine the energy efficiency and production costs of a full-scale plant.

Tordenskiold back on test site

In February 2020, Crestwing's prototype Tordenskiold was towed back for further testing at sea northeast of the Hirsholm islands in Kattegat, just outside Frederikshavn. It is the second test period at sea for the installation. Tordenskiold has previously been tested in the same site for 5.5 months with several good results. In May 2019, the plant was towed to harbor to be optimized and improved in relation to the PTO and data collection. - I have high expectations for the new test phase and hope that we get many answers and well-documented data, says Ruth Bloom.

Further reading about Crestwings development phases.

Well on the way, after successful test


Tordenskiold is well on the way to optimisation, after its first test on the ocean. The completed test was successful, with good results. Our anchoring held in all types of weather and we have documented, that the equipment produces energy, which was our prediction.

“We cannot be anything other than satisfied after the first five months. The test on the ocean has given us a huge amount of documentation, that the equipment produces energy, even more than the equipment generator is capable of at this stage”, says a very happy Ruth Bloom, Director of Crestwing.

Half size of the North Sea plant

Tordenskiold is in scale 1:2 of a similar plants designed to exploit the power and size of the waves in the North Sea. Calculations and tests are done at Aalborg University (AAU) and the Danish Hydraulic Institute (DHI). Read more about Crestwing's developmental phases.

First prototype is launched
Crestwings prototype Tordenskiold is launched in Kattegat in the autumn of 2018, northeast of the Hirsholm Islands. The plant messures 30 x 7,5 m with a weight of 65 tons.

The purpose is to test the plants's anchorage and function at sea and confirm the expected production of energy. It has taken Crestwing from 2005, to get to the point of a prototype that can easily be scaled up and produced. The price to reach this far has been about 30 million DKK. This indicates that Crestwing can produce plants and energy at a kWh price, which corresponds to the production of other renewable energy types.

Test periode of two years

While Tordenskiold is located on site next to the Hirsholm Islands, the entire plant is monitored and tested, the size of the waves measured, and there is a continuous development on PTO, hinges and anchoring. Out of this, a report will provide a basis for the development of the next generation of the plant.

Measurements from land

The following measurements can be monitored from land:

  • Hinges, push rod and anchoring forces
  • Power generation
  • Wave height
  • Wind force
  • Rotations in generator, flywheel, etc.
  • Temperature and humidity in the engine room
  • Machine rooms and hinges will be video monitored


Ongoing development


Alongside the tests and documentation of Tordenskiolds effectiveness and function at the site in Kattegat, the company is working on the following:

  • Find investors, buyers and apply for state and EU funding
  • Further develop and improve the effectiveness and function of Tordenskiold
  • Plan and design a 1:1 plant to be tested in the North Sea