Slashdot Mirror
Harnessing Vertical Sea Temperature Gradient
Sterling D. Allan writes "Sea Solar Power Inc., run by three generations of James Hilbert Andersons, has developed a solar power technology that does not fluctuate with the weather, but is available constantly. Their solution is to harness the solar energy stored in the sea by tapping the thermal gradient that exists naturally between the surface and deep waters, using a reverse refrigeration cycle. The modeling and testing done by the Anderson family over three generations since 1962 predicts that the cost of energy generation through this method will be within a price range comparable to nuclear, coal, natural gas, and other contemporary grid power plants. Ocean Thermal Energy Conversion, or OTEC, was invented in 1881 by a French scientist, Jacques Arsene D'Arsonval. SSP should be ready to build their first full prototype 2-3 years from now."
Aquethermal, if you please! It's only solar in the sense that all power on Earth apart from geothermal is solar.
For the love of God, please learn to spell "ridiculous"!!!
"SSP should be ready to build their first full prototype 2-3 years from now.""
It will run Linux (everything else will by 2007-2008)
"...using a reverse refrigeration cycle."
We have a name for those. They're called engines.
Fitzghon
Deja vu!?!
There is a global circulation system called thermohaline. Basically in three relative small areas of the oceans the water sinks until the bottom, and then spread around the world. This water slowly go up again and the system is closed with surface warmer waters flowing in direction of the areas of generation.
I'm not even considering the energetic balance of the proposed structure, but if it works it might reduce the vertical thermal gradient and make the thermohaline circulation weaker. Maybe stop it. The movie "The Day After Tomorrow" is a fantasy about it, but be sure at least that the surface temperature on the North Atlantic would reduce since is one of those areas of generation of deep waters. You can imagine how would be the winter on Europe and North America? Would need a lot of energy to keep people warm there!
There are a few prototypes. Search for OTEC on google. The problem is, there isn't enough of a temperature difference to efficiently extract any useful energy. You basically have to pump HUGE quantities of water (like a 10m diameter pipe) to the surface and have enormous heat exchangers and stuff that extract the energy. You use a lot of energy to pump the water and it requires enormous capital investment for very small amounts of energy.
Wikipedia entry on the subject of Ocean thermal energy conversion: http://en.wikipedia.org/wiki/OTEC
I guess I am being punished by my mechanical engineering background.
It is possible that there is some good information on this site (somewhere), but quite frankly I do not know what you would want to waste time separating the real information from the quackery.
----- There are two kinds of people in this world, my friend; those with loaded guns, and those who dig.
Looks like we have covered this topic rather well.
The discussions were better on those, too.
Jack
Yeah, there is nothing new about this, I think this is some kind of a slashvertisement. The technology that OTEC has been developing in this field is interesting. Hopefully it will ultimately pan out.
t ml
:)
Here's where I have seen more about this technology before:
http://www.wired.com/wired/archive/13.06/craven.h
http://www.nrel.gov/otec/
Enjoy
Yup that would alter the environment too. In this case you're adding massive amounts of the energy to the Earth's natural systems from an outside source that wouldn't have been inserted into the system normally (ie you're taking energy that wouldn't have hit the earth and transferring it there). Although you may be thinking that this is pure electrical energy and has nothing to do with the environment, energy cannot be destroyed or created but only transferred. This electrical energy is disappated into the Earth's natural systems in the form of heat and even in (minute) changes to the Earth's orbital, rotational, and geothermal energy. To say nothing of the greater environmental energy systems at work beyond our earth.
Basic physics dictates that no matter what we do energy-wise, it will affect the Earth. It's a matter of what changes we consider appropriate.
This is the lyrics from the song "Under the Sea" from The Little Mermaid.
Gosh, I am disappointed in the quality of nerds these days. Ever heard of the back of an envelope? For god's sake, units of energy are defined by how much they heat water, so it's not hard to figure this one out.
Projection from http://www.eia.doe.gov/oiaf/ieo/world.html is that the world will use 645 quadrillion BTUs of energy per year in 2025. If we assume this all comes from the ocean at 100% efficiency, this would be enough to raise a patch of water, 100m deep by 1024km on a side, by 1 degree C. Insignificant next to the whole ocean? sure. But certainly significant compared to local or even regional climate variation! (not that hydrocarbons aren't worse, or that this can't be spread out but hey, now all the slashdot blather can be vaguely informed. sheesh).
"Research by raptor experts for the California Energy Commission (CEC) indicates that each year, Altamont Pass wind turbines kill an estimated 881 to 1,300 birds of prey"
/ bdes/altamont/altamont.html
That is not a large number at all, cars, buildings, pets, power lines, etc, etc kill WAY more than that. And the altamont pass is the single worst wind farm in north america for bird of prey deaths, because they were stupid and built it not only in the middle of a migratory path, but in the middle of the highest concentration of breeding golden eagles anywhere in the world, and with the blades positioned right at the typical altitude of those birds flight paths. This is exactly what caused the myth; old, improperly planned wind farms that haven't been fixed. Learn to find facts instead of just repeating nonsense you heard from whackjobs.
The fact that you think the tiny number of bird deaths produced by the worst wind farm on the continent is "substantial numbers" is just silly. And the fact that you pretend its indicative of modern, properly planned and constructed wind farms is just plain stupid. You can't say wind farms in general kill substantial numbers of birds just because a couple of bad wind farms were built.
The quote is from this page, there's more info there about what can be done to improve altamont specifically:
http://www.biologicaldiversity.org/swcbd/programs
It may, theoreticaly, result in the emission of some greenhouse gasses. Warming the lower depths of the ocean would reduce its ability to hold dissolved gasses such as methane and carbon dioxode.
On the other hand, it may not be a problem because tropical waters may never have been cold enough to hold much gas in the first place.
"Prefiero morir de pie que vivir siempre arrodillado!"
The hot core is due to radioactive decay of granite into a molten core of geo-goo. While friction is certainly a property of interest within the vicous materials below the mantle, it's not in line with your above classifications.
While current planet theory involves a rotating iron core, quite impressive local magnetic fields play havoc with the already poorly defined theory to a point I would not feel comfortable in believing it be a major contribution to geothermal heat. Of course, it would be equally correct for one to believe the complete opposite, mate - we don't know!
Cheers!
-Lewis
The energy needed to lift heavy things (like water) is greater than the energy in the temperature difference.
If you believe this then your entire post is suspect.
This process won't have to 'lift' any water. Since they are moving the water up in a tube which is surrounded by water, they are really just circulating water around, which requires very little energy. By your logic it would be impossible to coast on a bike, since you have to continually lift the part of the tire touching the ground all the way up to the height of the tire.