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Underwater Ocean Kites To Harvest Tidal Energy
eldavojohn writes "A Swedish startup has acquired funding for beginning scale model trials of underwater kites, which would be secured to a turbine to harness tidal energy for power. The company reports that the kite device allows the attached turbine to harvest energy at 10 times the speed of the actual tidal current. With a 12-meter wingspan on the kite, the company says they could harvest 500 kilowatts while it's operational. This novel new design is one of many in which a startup or university hope to turn the ocean into a renewable energy source."
Seems this would be relatively high maintenance. Anyone who owns a boat knows that stuff can and will grow on it, which will have to be cleaned off eventually, no? Setting aside the initial cost, which isn't mentioned, wouldn't the maintenance be costly?
well based on what i have read - as the moon/tidal effeects work the earth is slowing down and the moon is gaining potential energy related to earths gravity well by moving farther away - assume this is a colosed energy system..
assume we pull energy out of it.. the moon will come closer to earth (or reduce it's movement away) - so the total energy supply would be the potential energy of the moon in relation to earths gravity well.
PE = m x g x h
m = 7.3477 × 10^22 kg
g = 9.8 m/s2
h = 363,104,000 m (using it's Periapsis)
PE = 2.61461968 × 10^32 Joules
474 × 10^18 = AEC = whole planet annual energy consumption
PE/AEC = 551,607,527,000 years....
so the answer is .. keep current rates.. and assume we could get it all from here.. 550 billion years..
according to this #19
http://helios.gsfc.nasa.gov/qa_sun.html
"In about 5 billion more years, the useable hydrogen (not all the hydrogen) will have been converted to helium, and the Sun will start burning helium, and become a red giant."
if i remember right.. if it goes red giant it will grow larger than 1 AU so it will engulf earth..
basically.. we could increase energy consumption by a factor of 100 and only then would we be toying with maybe crashing the moon into us before the sun burns us away.
'...if only "Jumping to a Conclusion" was an event in the Olympics.'
A follow-up question- would it be possible to build so many solar panels that all the energy from the sun gets sucked up and the planet freezes over?
Like windmills, PV solar (and arguably, thermal solar), this will use a ton of capital (in multiple dimensions -- energetic, costs, and materials) to harvest very diffuse energy.
Kites use two orders of magnitude less material than a turbine of equivalent swept area. Water is two orders of magnitude denser than air.
This is starting to add up to something that doesn't sound so diffuse any more.
Stop worrying about the risks of nuclear power and start worrying about the risks of not using nuclear power.