A powerbuoy is what its name implies – buoy which is used to generate power or electrical energy. The basic principle is same as that of a tidal power plant although the scale and size are no match to each other, with a buoy just being a tiny speck as compared to a full fledged tidal power plant.
Offshore Power Generation Systems
Powerbuoys and similar equipment such as underwater turbines and wave generators fall under the category of offshore power generation equipment as compared to their onshore counterparts which include hydroelectric dams etc. Such offshore systems are a recent appearance on the stage of alternative power generation but they do offer some pretty solid advantages although their generation capacity is limited currently. It is hoped that with the passage of time these devices would play an increasingly important role in fulfilling the power requirements of the world.
The figure below shows a typical powerbuoy array used in electricity generation from the water currents. These particular powerbuoys have been patented by Ocean Power Technologies of New Jersey but any other buoy would operate along similar lines and same principles of power generation.
The basic difference of a powerbuoy from an underwater turbine is the lack of blades to convert the motion of water into rotary motion of the turbine. Instead these have a piston and cylinder type of arrangement which moves up and down as waves pass through it. This to and fro motion is transmitted to a hydraulic fluid which drives a hydraulic motor and finally generates electricity. The power output cables of each of these buoys are combined together into a single output and finally fed to the shore where they can be used to deliver electrical energy to the required consumer.
The typical area of ocean surface covered by a set of such buoys which generate electricity of the order of 10MW is just around 0.13 square kilometers. This is quite less and added to the fact that the visual impact of these buoys is nearly nil i.e. they are not visible from the shore.
Features of a PowerBuoy
Powerbuoys are used near the surface of water and hence their use is only limited by such areas available near sea shores. There are plenty of regions across the globe which have such suitable conditions including but not limited to Europe, South and North America, Asia and Africa.
It does not need much reflection to figure out that as compared to say the underwater turbines these structures present a much safer view for bigger marine life with not turning cutters (blades) which could inflict damage on the marine fauna.
In case the waves are of very high intensity due to a storm, these generators are so designed so as to cut off production during that time to ensure safety of the equipment and resume when things are back to normal.