Challenges

Home

Maritime operations are demanding. Items staying at or near the ocean surface for a long time have to withstand storms. They must endure persistent nagging and wear from waves and currents, through months and years. Seawater corrode many materials, especially metals. And marine life will adhere to most materials.

Fouling

Mussels, bryozoans, barnacles and different kinds of seaweed will soon attach themselves to almost any surface. With time it can be so bulky that it inhibits the movement of buoys and cables.

 

Corrosion

Metals staying in seawater for a long time will be exposed to corrosion. Particularly significant is the effect if there is some kind of electrical voltage involved. It can be the result of contact between different metals, or the generation of electrical power.

Storms

All parts of a wave power plant must withstand the stresses they are exposed to in a storm. Not only in one storm, but in many. And not only in common storms, but also in extreme hurricanes. At the same time the wave power plant must be "sensitive" enough to convert the energy in usual waves which is most frequent. And, if the plant can still produce power when the storms are at its worst, it increases the yield dramatically wich will strenghten the economy of the project.

Costs

Maritime operations tend to be very expencive. Especially when large devices and subsea operations are involved.

The challenges can be tackled

Storms

Storms is the hardest challenge. The main point of Waveco's Subwave technology is to place the vulnerable, sensitive part of the power plant, the turbine, below the wave zone. The waves are most forcefull on the surface. When the depth is greater than half the distance between two wave crests, the wave motion is negligible. In this calm water the Subwave turbine can operate safely, regardless of the conditions on the surface. The buoy, however, must be strong enough to withstand the beatings there.


Under the wave zone, the water mass is at rest.

Fouling

Not only the waves, but also the light, decreases rapidly with the depth. Plants need light to do photosynthesis. Plankton, both plants and animals, therefore lives in the upper water layers. The turbine down in the darkness will therefore be lesser exposed to growth than objects near the surface.

The light decreases rapidly with the depth.

Corrosion

The plastic polyethene (PE-plastic) contains no harmful substances, only hydrogen and carbon. It is a rigid plastic material and is used for wastewater, water and gas pipes, food boxes, toys and more. The density is close to ice, that is, a little lighter than water. Wet PE-plastic surfaces have low friction against each other. The material is therefore very suitable for the body parts of the Subwave turbine. The flexible wings will be made of extremely durable polyurethane plastics. Also this plastic is unaffected by seawater.

Polyethene (C2H4) is completely unaffected by sea water

Costs

A number of turbines can be linked together in a chain or field, anchored at the edges. Horizontal cables keep the units together and in position. The cables will be placed deep enough for service vessels to operate above. The turbine can be hooked on or off the connecting point between the units as illustrated in this sketch. This means that both deployment, maintenance and cleanup can be carried out without the need for expensive underwater operations.

Home