There are already a wide variety of renewable energy systems that harness the power of the wind, along with some that generate power via the flow of ocean currents. According to Japanese engineering firm MODEC (Mitsui Ocean Development & Engineering Co.), however, its soon-to-be-tested SKWID system will be the first one to do both.
SKWID stands for Savonius Keel and Wind Turbine Darrieus. This is appropriate, as it’s an anchored floating platform that contains both a Savonius tidal turbine below the waterline, and a Darrieus vertical-axis wind turbine up in the air. The two are connected by a central gearbox/generator, allowing the SKWID to generate power from the currents, the wind, or both. Additionally, the rotation of the tidal turbine can be used to help get the wind turbine spinning, when breezes are light and it needs a bit of extra inertia.
The design of the Darrieus turbine is such that it can spin to the left or to the right, so it works regardless of the wind direction. The tidal turbine spins in just one direction, but it does so irrespective of the direction of the current. It is reportedly able to harness even the weakest of currents, and is not affected by marine growth on its half-cyclinder-shaped buckets/blades. Additionally, because it spins no faster than the current, it is claimed to be safe for marine life.
The SKWID shouldn’t be too likely to tip over in rough seas, as the deck-level-mounted generator and below-deck-mounted tidal turbine help keep its center of gravity low. Additionally, the ring-shaped deck (which is the source of flotation) is joined to the central structure via flexible rubber mounts, allowing it to rock back and forth with the waves while the turbines and associated machinery remain stable and upright.
According to a report on Japan’s NHK News (relayed by America’s CBS News), one of the SKWIDs is due to be installed and tested off the coast of Japan, sometime this fall (Northern Hemisphere). The wind turbine should sit 47 meters (154 feet) above sea level, with the tidal turbine having a diameter of 15 meters (49 feet). Together, they may be able to generate enough power to provide for approximately 300 households.
I would like to state my view here. Let the big things be installed on a larger scale but at micro or local level efficiencies and micro generation be the buzzword. Every country has an economy to run, industries to grow and life to be enjoyed by its citizens.
Here is my calculation. I have a 29" CRT TV which consumes 130W of power. In our home we have four FTL tubes which consume on an average 40W of power. I have a PC which consumes 110W of power. A refrigerator wattage of which I have not seen. Three cell phones. If I can reduce my usage with new LED Panel TV, LED light with addition of solar pv power to the mix, I will reduce the load on the grid. If most of families in my community first then in the city later would take us of the grid.
Municipal corporation in my city, has street lights with Sodium or Mercury vapour. Slowly they are replacing them with LED. They in turn are becoming efficient, their efficiency over time will reduce our taxes. If they install solar panels, then after the initial investment recurring costs are nil. Excess power generated can be channelled through F-I-T. Power generated by big units can be directly sent to big consumers i.e. industries, commercial complexes, railways. etc
I think you misunderstand. Vertical axis wind turbines are designed to rotate in one direction only. But the fact that the axis is vertical means that the wind direction is irrelevant. Seen from above, the turbine looks exactly the same in all directions.
It's unclear whether there's a gearbox for the Darrieus rotor since it's likely to rotate faster than the Savonius. At the very least, there should be some kind of clutch for both turbines. It's unwise to couple together two mismatched sources of power. You could end up wasting tidal power turning the wind turbine during times of still winds, or conversely, the tidal turbine could be a drag on the wind turbine during times of strong winds. Of course, the latter could be an advantage if it can act as an effective brake to slow down the wind turbine during high winds that would otherwise damage it.
So rationally considering the strengths and weaknesses of an alternative energy supply makes one addicted to addicted to cheap fuel. Interesting.