"Closed" Cycle Internal Reaction Engines

Presumably you mean the 300 ExaJoule figure to be annual "current world usage"? If so, it is out of date -- 2005 global commercial energy use was more like 440 ExaJoules. Further, we need to think about the 60% of the human race that is currently seriously underserved in energy. And we need to recognize the significant additional energy demand coming from using a very inefficient energy source such as the ocean temperature gradient. The real target energy production figure is more like 4,000 - 5,000 ExaJoule, using so-called renewable sources.

But your point is well taken -- lowering the average temperature of the oceans by only small amounts would potentially make very large amounts of energy available. However, your cooling estimate is wildly misleading because it assumes that we successfully cool the ENTIRE oceans of the globe evenly, all 70% of the planet's surface, coastline to coastline, surface to abyssal depths -- all 1.4 * 10^24 grams of it. Look at a globe: there are parts of the Pacific Ocean that are about

6,000 miles from the nearest continental coastline -- how would we cool the water there? how would we deliver energy extracted from that location to the point of use? Practically, use of ocean temperature gradients would mean much larger temperature drops over smaller parts of the ocean surface -- which would likely have anthropogenic global climate impacts analogous to the El Nino/La Nina phenomenon.

I don't follow your point about "shallow lagoon aquaculture". First, scale -- how does the area of those shallow lagoons compare to the 70% of the planet's surface covered by oceans? Second, what are they there for? Carry out a thought experiment -- you have two large insulated tanks in front of you. One holds warm water. The other holds cool water. Your job is to transform part of the energy in the warm water tank into mechanical work. How will you do it? (Hint -- you are going to need a working fluid). So what is in those shallow lagoons?

Gawd, I hate to do this, but...it's Dr. Lucas to you.

Sorry, paraphrasing...but not inaccurately, based on your gloom-and-doom assertions.

That's a truly amazing sentence. You set up an unsubstantiated strawman, and use tearing it down to support your other unsubstantiated claims. The vacuousness is mind-boggling.

Nor is there room for glib dismissals of well-supported science, or unsupported assertions of gloom-and-doom regarding potential new technologies. (For the record, my gut tells me that both of those new technologies--high-altitude wind energy and ocean thermal gradient harvest--are ridiculous ideas at best, and could very well be environmentally devastating if either were implemented successfully. However, notice that I don't say that as if it were fact, and I make it clear that it's only my gut feeling.)

Extraordinary claims require extraordinary evidence...and it is part of the duty of any competent scientist is to point out when somebody is trying to act the expert in an area when they have not met their burden. I'd say the vast preponderence of the evidence is in support of anthropogenic global warming, so I'd say that that camp has met their obligation (which you choose to glibly ignore). You, however, make the extraordinary claim of planetary doom from two potential new technologies. I'd say any prediction of planetary doom is prima facie extraordinary, and so requires extraordinary evidence.

You wanted "content in my post" (is that a direct enough quote to justify the quote marks?) Pointing out your failure to support extraordinary claims is valid content in any science discussion. I'm not saying you're wrong. I'm saying you haven't given enough information to be taken seriously.

Eric Lucas

DOCTOR Eric Lucas (DOCTOR of what? we all asked) wrote, inter alia:

Sounds reasonable! So where is the "extraordinary evidence" for anthropogenic global warming?

Remember that the ordinary evidence is that the climate of this planet has been continuously variable for as long as we can determine, for hundreds of millions of years before any possibility of anthropogenic involvement. Remember also that the current climate is (to the limited extent that we can measure such things) well within the bounds of past natural variability. As a DOCTOR (of something), you surely must have a well-founded basis for your apparent support of alleged anthropogenic global warming?

OTEC uses the warm surface water as the working fluid, a pressure gradient is established and used to lower the boiling point of the water below the surface tempature. The resultant steam is used to run a turbine. The deep water is then used in a heat exchanger to condense the surface water and maintain the pressure gradient. The result is a large amount of fresh water and salt water all at the weighted average tempature. The freshwater is used for irrigation and drinking, the salt water is pumped though shallow lagoons to deliver minerals for aquaculture. Between the aggitation in air and the solar area the energy that the OTEC extracted should of been returned to the water. That doesnt mean that the tempature isnt different but that the net heat is close. The water is then reinjected around 100meters underwater in the transitional area.

I was wrong in my math in my last post, the use of total water weight is incorrect since after about 500 meters the water tempature is very stable, but I also made another mistake I confused calories with joules, the actual tempature change would only be a 1/4 of my previous estimate, Taken together that actually they nearly cancel each other out since the vast majoity of the ocean's mass and heat are above

2000meters.

Since all the energy output of OTEC is electrial, nowhere near 440 Exajoules would be needed to mean current demand. Current energy use is only about 10-15% electrial and 85-90% thermal. Electrical energy is worth 3-4 times what thermal energy is since the ineffiencies of heat engines dont effect electrical systems. Carnot has been paid already.

Now that doesnt mean that you can hand wave away the massive expensive and work of changing the infrastructure but if you make electrical energy cheap enough the switch will occur naturally in order to take advantage of that cheap energy.

Ghostwriter

Accord> I was wrong in my math in my last post ...

Yes, I know. Your physics was not that great either. Nor have you addressed the question about the validity of your assumption that you could cool the entire oceans of the globe evenly.