Harnessing Vertical Sea Temperature Gradient

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."

How is this solar power exactly?

[Richard]

Solar power by proxy?

[debs]

I know its on a small scale and everything but is it good to be messing around with the temperature of the sea like this?

[bruce]

If the energy they'd be taking is a tiny fraction of the overall energy (as I suspect) then I doubt it'd make a blind bit of difference.

[reality]

Actually the article mentions that this form of energy can produce around 300 times the current global energy usage so is pretty impressive. It also sounds like it creates fresh water as a by product so could prove doubly impressive if the technology reaches the market.

[mgopilot]

I can't wait to see the results over time of the new ship/powerplant. It looks promising, but I wonder about the oxygen removal with local marine life. I wonder if this really will stop marine growth when there are species that don't use oxygen. I wonder about storm resistance and that cable to shore. Interesting to see the results, especially with the cold water intake pipe after 6 months.

[Centrillium]

Ocean Thermal Energy Conversion (OTEC) has been around as a concept for a very long time, as the article notes. I don't think many people think of it as 'solar power' in any sense, although it might have a little more claim to such a label than, say, wind power, depending on how you look at it. (Wind power uses the atmosphere as a working fluid heated by solar energy, while OTEC uses the sea as an energy storage medium for solar energy, with a self-contained working fluid.)

If these guys can produce OTEC power at rates competitive with conventional sources, then hats off to them, but the fact that the website is also pushing cold fusion and zero-point energy leaves me doubtful. OTEC is definitely a workable concept but its nowhere near competitive yet.

To discuss people's concerns: debs, wind power takes energy out of the atmosphere. Tidal power takes energy out of the sea. All renewable energy sources are in some way exploiting an energy flow that happens in nature, and diverting it for our purposes. OTEC is no different, the effect it has depends entirely on the scale at which it is done. If wind power were used to meet all our needs we'd be tapping a non-trivial portion of the atmosphere's kinetic energy, at least at low levels.

Mgopilot, I can't dismiss your concerns... I imagine the oxygen must go somewhere, and if its into the air - well, I guess there's an equilibrium between oxygen in the air and oxygen dissolved in the sea? Hmm. Not my subject. The other issues you mention are engineering problems... I guess the engineers will have anticipated them if this is a real project, and solutions will exist.

On another note, the real environmental issue that bears considering with OTEC is the working fluid in the powerplant. It has to have a very low boiling point, so all the prospective choices have toxicity issues - ammonia is the most often suggested, these guys are using propylene which should be a little better. In theory, the working fluid is isolated from the environment, but if a large OTEC plant leaked refrigerant into the ocean it could put nuclear scare stories into perspective (from an environmental point of view at any rate, fortunately nobody lives in the sea).