THE WORLD WITH CLEAN ENERGY Imagine a clean energy source, inspired by the human heart, with the potential to generate 10-20 percent of all electricity needed globally

Corpower Ocean is determined to create wave power that can handle tough storms and tight budgets. Armatec has supplied vital components for this, until now, secret project.

A STRANGE PHONE CALL In late 2013 a man called Fredrik Johansson at Armatec and asked many questions about pressure relief. To get involved with the mysterious project Fredrik had to sign a document of confidentiality. Fredrik commented “The technical challenges were out of the ordinary which was the thrill of it for me.”

EXTREME ENVIRONMENT The ocean’s energy supply is endless but nobody has been able to develop wave power robust enough to withstand its power while delivering energy at a reasonable price –

Corpower is changing that. Patrik Möller, CEO of Corpower Ocean explained: “We have developed highly efficient wave power converters inspired by the human heart – behind the technology is cardiologist Stig Lundberg. A buoy with an air spring inside generates energy, similar to the heart muscle’s movement when pumping blood.

“The buoy extracts five times more energy than traditional wave power plants for a third of the cost, which makes the technology highly relevant.”

ELEVATED TECHNOLOGY The buoys of 20 metres will be in constant use for 20 years which makes maintenance difficult and complicated. That’s why each product in the redundant system is selected with great care.

Armatec supply the ball and safety valves. When a wave sweeps in, a giant air spring in the buoy is pressed and then retracted. If pressure gets too high, the safety valves have to be trusted to let the right amount of air out.

Patrik concluded “Armatec are technically experienced and understand our high demands, who have the knowledge to suggest the best solution which is a perfect match for us”.

Corpower Ocean will carry out tests off the Orkney Islands in Scotland later this year. If successful it will be a huge industrial breakthrough and the map of global energy supply will be redrawn.


The main purpose of the work is to achieve structurally safe solutions with as low LCOE as possible.

HOLISTIC SIMULATION MODEL The Swedish Energy Agency has supported the group in a number of projects to develop a holistic model suitable for parametric studies of specific WEC system components such as the mooring lines and the umbilical cable (dynamic cable) between the WEC buoy and a power-collecting hub. The simulation model is used to assess a WEC system’s performance during various operation conditions (wind, sea-state, ocean current, biofouling), to maximise the energy harvesting and to minimise the maintenanc an the LCOE.

MOORING LINES AND DYNAMIC CABLES ARRAY SYSTEMS These system components are critical for a WEC system’s performance and functionality. The group works in


cooperation with among others Waves4Power AB and CorPower Ocean AB on the assessment of mooring solutions and materials and with NKT Cables AB on the development of the next generation of dynamic cables designed for the maritime environment. A new novel cable simulation model is under development which should be used for detailed design and analysis of a cable’s mechanical life and ensure no loss of electrical conductivity. Mechanical testing is carried out in cooperation with RISE Research Institutes of Sweden.

Large scale harvesting of wave energy requires array systems of wave buoys. Different types of array system solutions are studied, assessed and optimised using the holistic simulation model. Each array system is evaluated with regard to LCOE, LCA and risk analysis.

MODEL AND FULL SCALE EXPERIMENTS, ELASTIC MOORINGS AND ARRAY SYSTEMS The simulation model has been validated against model scale experiments (1:20 and 1:36) in an ocean basin. In an ongoing project funded by the Swedish Energy Agency, it is used to assess and improve the performance of Waves4Power’s WaveEL wave buoy which is installed outside Runde in Norway.

The group is one of the partners in the OCEANERA-NET project

ELASTMOOR led by Instituto Superior Técnico in Lisbon, Portugal. The project emphasis is on comparing elastic mooring systems for WEC systems and developing simulation models for their assessment. The WaveEL wave buoy is one of the demonstration cases.

Chalmers University of Technology Division of Marine Technology 27


The Wave Energy Group on the Division of Marine Technology on the Department of Mechanics and Maritime Sciences, Chalmers University of Technology, develops simulation models for structural integrity analysis of mooring lines and umbilical cables used in wave energy converter (WEC) systems.

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