Marshall Brain's Blog

OTEC has been in the news since dinosaurs roamed the earth, or so it seems sometimes.  I recall seeing it on the cover of Popular Science no later than the 80's, more likely in the 70's.

Experiments have been running for the last two decades or so.  None has yielded the breakthrough which would lead to widespread adoption, and I doubt anything can.

-  The capital costs of large cold-water pipes aren't easily brought down.
-  Sites with cold, deep water available close to shore don't seem to be where power is wanted very often.
-  OTEC power doesn't pay for itself; it needs other products (fresh water, cooling) to make the venture pay.  Getting all of those things together compounds the difficulty.
-  The rarity of sites which can profitably exploit OTEC means little investment money, so the economies of scale have never been available.

It seems that OTEC pops into the news every time energy issues make it into the popular consciousness.  Unfortunately, it may be the perpetual also-ran to technologies with wider geographic possibilities, more rapid cost reductions and better prospects for improvement.  Solar PV is going to go a lot further than OTEC.