The wave power challenge

Why has no one succeeded?

Technical challenges inherently associated with ocean waves can be seen as the root cause explaining the relatively slow progress of wave power compared to wind:

  • Slow wave motion requiring high machinery force to absorb substantial amounts of power
  • Reciprocating motion requiring a mechanism able to absorb energy in multiple directions
  • Harsh ocean environment requiring structures to withstand extreme loads in storms
  • Highly fluctuating instantaneous power levels of a given sea state.

As a result Wave Energy Converters have so far been large and costly compared to their energy output, which has prevented industrial adoption.

How do we address these challenges:

  • Providing pre-tensioning between the buoy and mooring system using a pneumatic module, enabling 60-80% weightL2_Detailed_sunny reduction compared to conventional gravity-balanced devices. Increasing the natural frequency of oscillation and reducing inertia driven loading in storms.
  • Providing phase control by WaveSpring technology, giving inherently resonant response over a wide bandwidth. Amplifying the slow (0,5m/s) wave motion to 3-4m/s buoy motion.
  • Converting the amplified linear motion into high speed rotation using a durable and compact cascade gear unit with high conversion efficiency.
  • Temporarily storing the absorbed wave energy as mechanical energy in flywheels, gradually converting it to electricity using small generators. Providing power smoothing for effective grid integration. Allowing electrical components dimensioned for average loading instead of peak loading, reducing the size of generators, converters and cables.
  • In storm waves, de-tuning the phase control mechanism, making WEC devices more transparent to incoming wave energy. Significantly reducing loads in high energy sea states, giving improved survivability without the need for huge dimensions. Reducing the cost of moorings, connectors, PTO and hull. The detuning has a similar function as the pitching down of the blades of a wind turbine in storms.
  • CorPower is one of few wave developers to dry-test all functions and performance of the WEC before ocean deployment.

These innovations enable CorPower’s Wave Energy Converters to have an energy-to-weight ratio higher than 10 MWh / ton, bringing wave power to the same level as modern wind turbines.