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Generating Power From Ocean Buoys and Kites
cheezitmike writes "Researchers at Oregon State University are testing a new type of wave-energy converter to generate electricity from ocean waves: 'Even when the ocean seems calm, swells are moving water up and down sufficiently to generate electricity. ... For decades the challenge has been to build a device that can withstand monster waves and gale-force winds, not to mention corrosive saltwater, seaweed, floating debris and curious marine mammals. ... In the most recent prototypes, a thick coil of copper wire is inside the first component, which is anchored to the seafloor. The second component is a magnet attached to a float that moves up and down freely with the waves. As the magnet is heaved by the waves, its magnetic field moves along the stationary coil of copper wire. This motion induces a current in the wire — electricity.'"
Meanwhile, researchers at Stanford are working to design "turbine kites" that operate at 30,000 feet, where air currents flow much faster than they do close to the ground. Ken Caldeira, a Stanford associate professor, said, "If you tapped into 1% of the power in high-altitude winds, that would be enough to continuously power all civilization."
I strikes me that in both these solutions, they are using a lot of vulnerable wiring to either transmit the current somewhere it can be used or to actually generate the current. Why not stick to the same principle as hydro-electric ? If you build 2 tall chimneys, one shorter than the other, and join them at the base via a turbine, the pressure difference between the two will turn the turbine. The higher the taller chimney, the greater the pressure difference. This works with or without a jet stream type phenomenon.
Implement a similar scheme in the ocean, where either a deep underwater current or just the simple pressure difference will suck (or blow) water down from (or up to) a higher level, turning a turbine. The turbine can be onshore for easy maintenance and repair. Drop one end of a rigid pipe to the bottom of the Marianas trench and you will have a pressure difference of 1000 times sea level. I realise you wouldn't see the full 1000x pressure at sea level but by gradually reducing the diameter of the pipe as it ascends you can maintain a considerable pressure difference. With both ends under water it creates a circuit with a turbine in the loop. You could even take the top end through a desalinisation plant for an agricultural or potable water supply. The pipe won't be crushed because the pressure at depth will be equalised inside and outside the pipe. The only problem might be crap being sucked into the pipe, but I'm sure there are technical solutions for that. Ocean currents are basically giant hydraulic systems anyway.
Yes I know you still have to get the power to where it will be used, but the current situation isn't much different anyway. You already have power lines stretching hundreds of miles, you already have trans-continental oil and gas pipelines.