Underwater Kites Could Harvest 64 Times More Power Than Undersea Turbines
How can we generate more power from renewable sources without using massive plots of land for solar and wind farms? Go fly a kite. According to David Olinger, an associate professor of mechanical engineering at Worcester Polytechnic Institute (WPI), tethered underwater kites could be used to generate large amounts of electricity by harnessing the power of ocean waves and currents. Olinger recently received a three-year, $300,000 grant from the National Science Foundation (NSF) to develop this technology, and work is scheduled to begin in January.
According to Olinger, deep see currents are rife with unharvested kinetic energy. Even though we can’t see them, these currents are latent energy sources that could be tapped by the kites Olinger wants to develop.
“Unseen under the waves, winding along coastlines and streaming through underwater channels, there are countless ocean currents and tidal flows that bristle with kinetic energy,” Olinger said in a WPI press release. “And just as wind turbines can convert moving air into electricity, there is the potential to transform these virtually untapped liquid ‘breezes’ into vast amounts of power. For example, it has been estimated that the potential power from the Florida Current, which flows from the Gulf of Mexico into the Atlantic Ocean, is 20 gigawatts—equivalent to about 10 nuclear power plants.”
Which would your rather have stationed around the coastline – a bunch of unseen, virtually harmless underwater kits, or a cluster of nuclear power plants? Yeah, that’s what I thought.
Here's a thought. Maybe the world's industrialized nations should pass legislation decreeing that for every new power plant constructed in a country, an existing plant of the same output must be decommissioned. No decommissioning, no new plant. It caps the nation's power output and over time cleans up its emissions.
Of course it would limit economic growth to whatever can be achieved through efficiency gains. But since we have been assured that GDP is now decoupled from energy use, that should present no problem at all.
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[font color="navy" face="Verdana"]Looks absolutely fascinating.
or late. This appeared in 2010. And the device is definitely a turbine with wings, if the artist's rendering is accurate.
Minesto-kites
Minesto, a spin-off from Swedish automaker Saab, (in 2007) is developing what it calls it's "Deep Green" technology, underwater kites tethered to the ocean floor that could produce continuous energy from tidal flows. A single Deep Green turbine could produce up to 500 kilowatts of electricity. And tides are much more regular than winds, so that the energy produced would be less erratic and variable.
The kites have a 12m (almost 40 ft) wingspan. The kites would remain at least 20m (66 feet) below the surface, to prevent conflicts with ocean navigation and minimize visual impact. Tidal flow as low as 1.6 meters/second can be used to create the lift necessary to move the kite.
Since the underwater kite is anchored to the ocean floor, it is able to move at much faster speeds, which makes the turbine more effective, as it traverses back and forth in order to generate electricity. Although wind-based deepwater offshore power systems are difficult to install and operate, Deep Green tidal kites would be well suited for instalation in deeper waters. Furthermore, the underwater kites are much lighter and easier to install than the equipment needed for other deepwater generation systems. Deepwater generating systems have the additional expense and technical hurdles of transmitting the power over a greater distance. But the higher efficiency and more consistent generation offered by Deep Green could offset those drawbacks.
The company indicates the Deep Green system offers an operating cost of 0.06-0.14 Euros/kWh, as compared to 0.15-0.30 Euros/kWh for other tidal systems, and 0.10-0.12 Euros/kWh for offshore wind systems.
A scale model of Deep Green will be tested in Northern Ireland next year as the next stage of development for this system.
http://www.ecogeek.org/component/content/article/3159-using-underwater-kites-to-generate-power