[extropy-chat] energy from osmosis

Mike Lorrey mlorrey at yahoo.com
Mon Oct 3 00:13:30 UTC 2005

--- spike <spike66 at comcast.net> wrote:

> > -----Original Message-----
> > From: extropy-chat-bounces at lists.extropy.org [mailto:extropy-chat-
> > bounces at lists.extropy.org] On Behalf Of Mike Lorrey
> > Sent: Sunday, October 02, 2005 11:18 AM
> > To: ExI chat list
> > Subject: RE: [extropy-chat] energy from osmosis
> > 
> > One other thing: You still need to preserve the 240m pressure
> > differential at the filter, you know, even when the pipe is full of
> > fresh water, which creates its own pressure...
> Ja.  My calcs show that if you have a 9600 meter pipe
> hanging vertically in the sea with a filter on the 
> bottom end and the pipe filled with fresh water, the
> pressure across the filter will be about 240 meters
> of water and the fresh water will reach up to the
> surface of the sea.
> Then by that reasoning, if the pipe end is deeper
> than 9600 meters, then fresh water would be raised
> higher than sea level.  Free fresh water, or free
> energy.  

A great way to fill Death Valley, the Rift Valley, and the Caspian with
fresh water free of charge. One issue, though: the depth of the ocean.
The average depth is only 3,720 meters. The Marianas Trench, though, is
11,033 meters in depth, so this technology could be used to provide
fresh water and power to that region. Hawaii, for example, is only
about 6,000 meters above the sea floor. The deepest point in the
Atlantic, the Puerto Rico Trench, is only 8648 meters or so.

> Mike your earlier comment made me realize this
> doesn't violate any cosmic principles.  You
> are dropping less dense fresh water at the surface
> of the sea, whereas the depths become more saline
> and thus denser.  In doing so, you slightly lower
> the center of gravity of the ocean, thus extracting
> a bit of potential energy.  Of course the tides and
> currents mix the sea, so what you are actually doing
> is very indirectly harnessing solar energy.

There is more fun you can have than just that. You can extract energy
directly from the salinity and temperature differences, ionically. The
thermocline is generally about 50 meters deep, while the halocline is
typically about 100 meters, with salinity increasing slowly with depth
beyond that point. Solar heated thermocouples can not only generate
energy from the differential from the depths, but can heat the column
of fresh water, which will decrease its density even further, which
will increase the height that it can reach (you need to figure the
temperature changes to fresh water density to adjust your numbers).

Mike Lorrey
Vice-Chair, 2nd District, Libertarian Party of NH
Founder, Constitution Park Foundation:
Personal/political blog: http://intlib.blogspot.com

Yahoo! Mail - PC Magazine Editors' Choice 2005 

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