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Tapping Thermal-Gradient Cold: Free Power or Planetary Suicide?
Advocates of tapping ocean
depths for “stored cold” promise a clean future of indoor comfort at low
cost. But is this practice really environmentally friendly, or is it a slippery
slope into unrecoverable catastrophe?
Opinion
by Mary-Sue
Haliburton
Pure Energy Systems News
Copyright © 2005
TORONTO, ONTARIO, CANADA -- The
Enwave Company, noted for its steam heating services, is now getting into air
conditioning by tapping Lake Ontario, which is deep enough to have a substantial
supply of water in its densest and coldest state. They promote their new
air-conditioning service by claiming that it has reduced electricity usage by 59
megawatts in Toronto. (ref)
Source: http://www.enwave.com/enwave/dlwc/
Deep Lake Water Cooling System
The company says that they are not pumping water out of the lake into
buildings, but merely sending it through heat exchangers. The idea is to replace
the many small electrically-powered units that use refrigeration technology by
pre-cooling in a central plant, then feeding the coolant to the surrounding
buildings. The company also says that deep-lake air-conditioning uses no CFCs,
and that it will continue to work during blackouts. This technology and similar
concepts are endorsed by Robert F. Kennedy and by various “Green”
organizations and individuals.
So, what’s the problem?
Transferring heat into the depths of the lake is the problem, though it’s
being touted as a solution to urban heat buildup. Eventually the added heat
circulated back into the lake from the heat exchangers will push the deep water
above four degree Celsius, the "anomaly point" that allows cold water
to sink but ice to rise.
Others are on this bandwagon, including John Piña Craven,
who is planning large-scale developments in coastal areas that so that he can
easily and cheaply tap the ocean’s cold depths. He says that what the world
needs is more cold, not more heat. While that is true in one sense, it is stated
in a backwards manner, and therein lies a misconception and a deeper issue.
John Piña Craven's concept:
Clockwise from top left: Power generation,
desalination, irrigation, refrigeration.
Source: Wired.com
June '05 |
An article in Wired Magazine refers to this cold water as
an “inexhaustible supply” for direct cooling, and for pulling fresh water
out of the atmosphere as condensation. “Running the frigid pipes through heat
exchangers produces unlimited air-conditioning that costs almost nothing,” the
magazine gushes.
In the minds of “boomers” and older readers, such blanket statements may
rouse uncomfortable echoes of 1950s promotional films, when we were being taught
as children that fish in the ocean were an inexhaustible supply of food that
could be harvested indefinitely. Now we are grown up, and aware of the
Newfoundland fishery that had to be closed due to depletion of the northern cod,
and that other fish species are under threat. Anyone remember the “tiny turbot”
incident? An illegally-modified net captured from a deep-sea turbot-fishing
vessel showed that this species was being taken while too immature to have
reproduced even once! No species can withstand that type of pressure.
By now we are – or should be – suspicious of that word “inexhaustible”
when it is being applied to any natural resource.
At its “anomaly point” of four degrees Celsius, fresh non-saline water is
highly resistant to temperature change. It is also at its greatest density. At
four degrees Celsius, it sinks below lighter layers of water that are warmer by
even fractions of degrees. At the anomaly point, super-cooled but liquid water
remains below ice due to the rapid expansion of H2O during freezing. And salt
water may be even colder than that.
Such cold but not frozen water has other unusual properties, as discovered and
elucidated by Viktor Schauberger. In his landmark book Living Energies, Callum Coats
explains those theories, original inventions and patents, emphasizing
particularly the critical nature of positive and negative temperature gradients
to the biosphere. When the temperature rises on land due to deforestation and
solar heating of manmade surfaces, rivers and other bodies of water become too
warm due to this ambient heat and removal of shade from the shoreline. In this
way, human landscape engineering based on ignorance of nature’s temperature
gradients disrupts the climate and leads to desertification.
There is, therefore, a serious risk to unrestrained tapping of deep lakes or
oceans to obtain and use this cold water. In moderation, and especially as an
interim measure to reduce reliance on combustion and nuclear methods of
electricity generation, it is tempting to feel that so-called deep-ocean cold
extraction may give us more time to move toward a sustainable-energy future in
which all life can flourish. However, to talk about transferring cold is a
backward expression that should set off warning bells.
Cold is not “given off” – in any concept of physics.
Heat, which is our perception of a higher energy state, is transferred into the
area of lower energy, which feels “cooler” to our bodies. This
process only feels – to our bodily perceptions – as if cold is “radiating”
which is of course nonsense. Cold is not an energy that can be tapped. It is a
lower-energy-state area into which we want to dump heat.
We must not wear rose-colored glasses. Expecting the great lakes and oceans to
stay cold indefinitely while we pump heat into them flies into the teeth of
logic. Just because deep-ocean warming may take a couple of decades, that delay
doesn’t mean it’s not happening. It takes a while to boil water after you
put the pot on the stove too.
As long as we thoughtlessly continue to build cities full of heat-absorbing
pavement and black tarred flat roofs that heat up to fifty or sixty degrees
Celsius, we are passively raising the temperature of significant areas of the
planet. To transfer this passive heat buildup into large bodies of water would
be slow suicide for the human race and all other creatures.
The better solution is to prevent the passive heat buildup in the first place,
by redesigning our cities and by retrofitting as many black roofs, paved and
bricked areas as possible with living green roofs, shade trees, and arbors
which, in giving back the oxygen from the carbon dioxide, utilize the sun’s
energy for photosynthesis instead of merely absorbing it. Studies show that
living green surfaces of leaves do not build up heat. On the contrary, the slow
evaporation of moisture from billions of leaves is nature’s refrigerator. This
actually helps to cool both the plants and the surface of the ground below them.
But I digress.
In the short term, there are profits to be made by exploiting this allegedly “free”
resource. One might argue that regulating how much heat can be transferred into
the lake or ocean, perhaps according to some formula related to its size and
depth, would mean this practice is acceptable. As long as we continue to monitor
the temperature of the deeper ocean layers and are prepared to cease operations
when the deep-water temperature shows signs of beginning to rise in response to
this activity, we might think that we’re not on thin ice.
But who would do, and pay for, this monitoring? Once a business infrastructure
has been built and is bringing in profits, it is sustained by sheer
psychological and financial inertia, and by political manipulation. Free
enterprise hates regulation. Corporations resist paying taxes, especially to
support monitoring of their activities. Should we let the plans to transfer heat
into deep water go ahead and trust business to regulate itself?
We’ve all seen examples of “self-regulating” industries pushing the
financial envelope and covering up environmental abuses. Think “Enron”.
(ref: The recent film, ENRON: The Smartest Guys in the Room, shows the complete
disregard for any principle other than maximizing profit. The attitude driving
this energy company led to criminal fraud on a massive scale.)
And, evidence is already in that deeper ocean temperatures are not
permanently colder. But spokesmen for profitable combustion-energy businesses
(including their minions in the current U.S. Administration) dismiss the
implications of the U.S. National Oceanic and Atmospheric Administration report.
Based on worldwide data and adjusting for all possible regional variation, this
report shows there has already been an increase half of one degree Celsius
overall in average ocean temperature worldwide over the past forty years. (ref)
This report indicates that this temperature change affects
deeper levels in the Atlantic Ocean as opposed to the Pacific, probably due to
the smaller size. (It takes longer to boil a big pot of water than a small one
on a burner of the same size.)
This change has been tracked over past decades and has occurred due to factors
already present before the use of extracting deep cold. And we are about to turn
up the heat under our global water-pot.
We can confidently predict that ocean warming will speed up once mining of cold
– i.e. transferring of heat into the ocean depths – is in full swing. Even
before large-scale ocean-sourced air conditioning is implemented, this oceanic
temperature increase will result in faster melting of Arctic ice, which in turn
is likely to contribute to increased warming due to loss of the white
heat-reflective ice sheets. And the severity and frequency of hurricanes, which
are generated over warm ocean surfaces, is likely to increase as well.
This is why we should regard this glowing advocacy of tapping the ocean
temperature gradient with a great deal of caution and skepticism. Cold, deep
water is a resource which is vital to survival of life on earth. And it is not
infinite.
In the light of this, then, I read with dismay the proposal of John Craven and
his investors to build developments based on tapping ocean cold. The ideal
location is an island with no continental shelf, so that it’s even cheaper and
easier to exploit that natural resource. “Sink a big pipe, crank a pump, and -
voilà! - you've entered a world powered by ocean water. Once primed, the pipe
acts like a giant siphon, requiring relatively little energy to keep an
inexhaustible supply of cold at hand.” Craven’s Natural Energy Lab is
already using a fifty-five-inch diameter pipe which puts 27,000 gallons a minute
at their disposal, twenty-four/seven.
There are those rose-colored glasses again. Inexhaustible supply feeds a giant
siphon and it doesn’t even need to be pumped up – that is, until the
temperature gradient becomes compromised and we end up in more serious trouble
than we are in now. Since the purpose of that plan is profit, not saving the
environment, we are free to critique both the concept and the outcome. The
planned development on Saipan will feature townhouses, a golf course, soccer
fields, and athletic complex, with the intention of attracting athletes who have
a healthy training budget.
The idea of making multiple uses of this same seawater is at least less wasteful
than merely mining for cold. For example, the Craven complex includes applying
cooler condensate water to plant roots to stimulate growth in greenhouses, at
least in species that like their roots to be cooler than their crowns.
And the contrasting temperature from surface and deep water is used to generate
electricity without combustion. The Wired article is rather vague about this
process, stating only that the warmer water enters a vacuum chamber and
evaporates into steam that drives a turbine to generate electricity. One is also
wondering where the energy comes from to drive the suction machine that creates
the vacuum. Is that how the solar energy is used?
Then the colder water condenses the steam back into drinking water, thus
efficiently combining desalination with power generation. However, that colder
water, now much less cold, is returned to the ocean, where it will not sink back
down to the deepest layers, but find its level according to the laws of
temperature gradient and laminar flow. Eventually the deepest cold layer will
become thinner as the warmer layers above it deepen and continue to get warmer.
Have climate-change researchers added this new variable to their predictions
yet? If not, it’s time to do so!
It may be a long time before the ocean’s reserve of anomaly-point cold water
is depleted, but it can happen given enough time and enough developments like
those of Mr. Craven. A rise of between eight and twelve degrees Celsius
worldwide is all that is required to make the planet uninhabitable. Therefore,
we should question this resource exploitation and challenge those who conduct it
for profit to prove their restraint.
To make environmentally-responsible use of this deep-water-cold, the power
company must not be permitted to regard it as a bottomless heat-dump. After
transferring heat into this water, the business exploiting the resource must
re-cool it back down to four degrees Celsius, before it goes back into to the
ocean or deep lake. This may perhaps be achieved cheaply by means of a
night-time cooling pond, and/or an additional expansion-coil in the outlet pipe.
(ref)
Otherwise we, or our descendants, may all come to a slow boil.
# # #
SOURCES:
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-
How
Air Conditioners Work - (HowStuffWorks.com)
[In the diagram at this site, both high- and low-pressure coils are shown
the same size, and the expansion valve is shown as a narrowing of the tube!
This could create confusion. Unfortunately search engines turn up many
diagrams purporting to explain refrigeration principles but which are
similarly oversimplified, failing to display pictorially the difference of
coil diameter between the high-pressure thin segment and the
larger-diameter, low-pressure, cooled segment. Would simple gravity pulling
water down through an expansion valve cool it sufficiently without further
application of pumping power?]
-
Ocean
temperature increase more proof of Global Warming! (18.02.2005)
(found at Profindpages.com)
Follow-up
From: Mary-Sue
Sent: Thursday, July 21, 2005 10:55 AM
Subject: [pes_news] Lake Ontario heating up, blackout threat - news
report
The Canadian Weather Channel reported today (July 21) that Lake Ontario is five
degrees warmer than it was last summer, and is therefore less effective at
cooling the nuclear plants. This increases the threat of rolling blackouts. Both
the direct heating from the sun, and using cold water from (i.e. transferring
heat into) the lake from industrial cooling are combining to produce this
heating up of a major body of water.
The above note should be appended to the article about cold-water air
conditioning, in which I questioned the assumption that this resource is
"free" and "unlimited".
MSH
See also
Page posted by Sterling
D. Allan June 3, 2005
Last updated July 21, 2005
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