Having already explored Ocean Thermal Energy Conversion and the reservoir approach to mechanical ocean energy harvest, it’s time to look at the wave action harvest technologies and companies.

This is pretty simple, the energy in the ocean (generated by wind, convection, and lunar gravitational pull) is expressed in waves and currents. One can clearly see the power of waves over time by looking at any coastline or by looking at the aftermath of a tsunami.

The methods for harvest of this energy are also pretty simple. In the case of a current, it’s the same as wind, a turbine is used mounted vertically or horizontally which is connected to a generator. A vertical axis ocean turbine from Blue Energy is illustrated below:



An artist’s rendering of a vertical axis turbine is depicted below:



These are accessible technologies and familiar to anyone who has ever seen a windmill in operation. There are some other, more exotic harvest technologies though as well. For instance, the oscillating water column, depicted below:



As the wave action occurs, a column of air is compressed in a tight space creating pressure. This air is driven through an efficient turbine as the wave comes in, and sucked back through the same turbine as the wave goes out when a vacuum is created as the wave retreats. This application could be applied on shore or in a floating device.

Another interesting class of harvest device are the pendulors. As the name suggests, there is a pendulum type device that is moved back and forth by wave action. The pendulum (I tend to think of it more as a paddle) is connected to a hydraulic pump which forces a working fluid through a turbine. This application may also be shore-based or floating. An illustration of a shore-based system is available below:



Since the ocean comprises the vast majority of the Earth’s surface area and has nearly unlimited energy, both mechanical and thermal, it makes sense to explore utility scale harvest of the resource. There are some efforts underway, but they pail in comparison to the amount of money being poured into wind and solar projects. This is an interesting opportunity for the right kind of investor….

This entry was posted on Friday, April 13th, 2007 at 9:18 am and is filed under Hydro.