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Friday, October 12, 2012



It was a little more than five months ago that I posted an article bringing the field of OTEC, which is the acronym for ocean thermal energy conversion, up to date.  The activity level has since then picked up.

OTEC works like a reverse refrigerator:  that is, it takes electricity to produce cool and heat (feel the back of your fridge), but in OTEC, the deep cold water and warmer surface water combine in a heat exchange process using an air-conditioner-like fluid to turn a turbine to produce electricity.  This water from depth also is very high in nutrients to re-start biological growth to support marine biomass plantations and next generation fisheries.  

Luis Vega of the University of Hawaii provides the details.  About that map above, the redder the better for electricity production.  You will note that Hawaii, while not optimally located, is sufficiently in the fringe to take advantage of this resource.  You will also recognize that typhoons are generated in the warmer region of our seas, so one possible by-product of the technology is the minimization or prevention of hurricanes.  Another environmental enhancement potential is remediation of global warming, for those extra nutrients mentioned in the previous paragraph could well induce growth so that in combination with additional nutrients, such as iron, carbon dioxide can be sucked up from the atmosphere.

My initial contact with OTEC was in the mid-70's when I served as director of the University of Hawaii Environmental Center, and had a responsibility to assess the environmental implications, as for example, the effect on the natural environment when those nutrient-rich waters were returned to the ocean.  During this period I also taught "Technology and Society" and was the campus ecologist.

But I shifted my purpose in 1979 when I joined the staff of U.S. Senator Spark Matsunaga in the U.S. Senate.  As soon as I started, Lockheed succeeded in producing net positive energy of 18 kW (closed cycle) off Keahole Point south of the Big Island with Mini-OTEC.  I was asked to work with the Senate Energy and Natural Resources Committee to prepare the first OTEC R&D legislation.  Rick Woldin did most of the drafting, so I blame him for inserting the expectation in 1999:  10,000 MW of OTEC.  For the record, a third of a century later, there is exactly ZERO MW of OTEC electricity today being generated.

Since Mini-OTEC, a Japanese consortium in 1981 produced 30 kW (net) of closed cycle OTEC on Nauru in the South Pacific.  Unfortunately, a typhoon largely wiped out the facility.  Then in 1993 the team I recruited for the Pacific International Center for High Technology Research (PICHTR) produced 60 net kW from an open-cycle OTEC powerplant at the Natural Energy Laboratory of Hawaii Authority (left).  The team included Andy Trenka, Luis Vega, Steve Masutani and Gerard Nihous.  Trenka now lives in Denver, while the other three work for the University of Hawaii.  While India made a run a decade ago without success, it has been nearly two decades since that last PICHTR achievement.


For the past half century, every ten years some company announces that they are close to building an OTEC powerplant.  In 1962 J. Hilbert Anderson of Sea Solar Power  (SSP )from Baltimore suggested so.  Bob Nicholson, originally from SSP, which has morphed into OTEC International, has regularly appeared every decade with confidence about their intentions.  Well, it is 2012 and OTEC International appears to be on the verge of signing a 100 MW OTEC deal with Hawaiian Electric Company for Honolulu, plus building and testing a 1 MW experimental facility (right) at the Natural Energy Laboratory of Hawaii Authority on the Big Island.  They are largely funded by the Abell Foundation.

Also in the running with, first, a 5-10 MW OTEC plantship, is Lockheed Martin.  Their sponsor has been the Department of Defense, and local firm Makai Ocean Engineering, has linked with both OTEC International and Lockheed Martin (LM).  The problem is that the U.S. Navy is not about to sink in hundreds of millions of dollars to bring this technology to commercialization.

That international partnership of LM with Taiwan, though, appears not to be happening.  India has also apparently abandoned their efforts.

During the OTEC Summit held at NELHA a year ago, Xenysys indicated their interest in building a prototype and hopes to have running a 50 kW demonstration plant in March of next year on Kumejima Island, Okinawa:

The last time I talked to them, Ocean Thermal Energy Corporation had signed a Memorandum of Understanding with The Bahamas Electricity Corporation to build two OTEC plants to provide electricity, potable water, aquacultural products and air conditioning.  Jeremy Feakins (left) is CEO and Ted Johnson, who long directed the Lockheed Martin OTEC efforts, is now with OTE Corp.  They have an interesting funding plan.  In particular, they are linked with China to participate in the $3.4 billion Baha Mar Bahamas resort featuring a Jack Nicklaus golf course and a 100,000 square foot casino.  Opening is expected late in 2014.

I've met several times with Al Yee (left person on the right) and Hans Krock about their Energy Harvest Systems.  They seem now to be focusing on smaller OTEC projects in the South Pacific.  Haven't heard much from Steve Oney and Krock's former company, Ocean Thermal Energy Corporation (also known as Ocean Engineering and Energy Systems), which has been seeking financing for a 6 MW OTEC plant with fresh water production for the Navy at Diego Garcia.

The French invented OTEC, and in the past entertained thoughts of this option for Tahiti.  There is some movement about a 10 MW system there, but more recently, Reunion Island appears now to have the edge for the first facility.  In 2005 I made an unforgettable journey to this island, and have since then kept in touch with their efforts.  They (left) visited Hawaii two years ago.

Finally, all the above projects will use the closed-cycle OTEC process.  There is virtue in open cycle for smaller applications requiring potable water.  At the summer World Renewable Energy Forum, Desikan Bharathan and I discussed how to facilitate this option.

Finally, Blue Revolution Hawaii has proposed the Pacific International Ocean Station for nations to cooperate on the development of OTEC for the Blue Revolution.  This would be the Planet Earth counterpart to the declining International Space Station.  There too is Shimizu's Green Float Project.

If you want more, go to:

  -   OTEC News
  -  NOAA (for licensing)
  -  History (Offshore Infrastructure Associates)
  -  National Renewable Energy Laboratory
  -  State of Hawaii
  -  Blue Revolution Hawaii

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