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By Robert Rapier on Nov 25, 2009 with 1 response

Potential Markets and Benefits from Ocean Thermal Energy

Happy Thanksgiving to those who will celebrate it tomorrow. I plan to spend the long weekend with my family, and probably won’t be on here much.

In the interim, two things. First is that it is about time to start thinking about the top energy stories of the year. As in year’s past, I would like reader’s opinions on the top energy-related stories of 2009. I will put up a post late in December with the ones that I think are most significant.

Second, I present a guest post by Dr. Robert Cohen on ocean thermal energy conversion (OTEC). Dr. Cohen has been an advocate of OTEC for many years, and has posted a guest essay here previously:

Ocean Thermal Energy Conversion

There were some useful comments following that essay that I think explain the challenges for OTEC. Dr. Cohen has a website where he addresses OTEC in more detail, and his contact information is also available there.



Robert Cohen, November 24, 2009

Once the Obama Administration and the Congress put ocean thermal R&D back on a fast track, one that leads to the maturation of this technology within a few years, ocean thermal energy can foreseeably provide baseload electricity to energize at least three major geographic markets (see the ocean thermal resource map on the next page) in the following time-frames:

1) An early market to displace the use of oil, oil that is presently being burned to generate electricity in places like Hawaii, Puerto Rico, and in many developing countries. Places that are relatively accessible to the ocean thermal resource. Years ago we estimated that that early market could utilize about 50,000 MWe, which amount would achieve an oil savings of 2 million BBL/day [calculated @ 40 BBL/day per 1 MWe of ocean thermal].

2) A near-term market for electricity generated (for example) in the Gulf of Mexico and delivered via submarine cable to the U.S. electrical grid at points on the U.S. Gulf Coast, such as Key West, Tampa, New Orleans, and Brownsville. This source of baseload electricity could substantially implement the priority strategies advocated by Al Gore and T. Boone Pickens, which are aimed at providing renewable energy for propelling vehicles.

3) A potentially vast longer-term market for products derived from electricity generated aboard a fleet of ocean thermal plantships grazing on the high seas. Those plantships would convert the baseload electricity (plus air and water) to energy-intensive products such as hydrogen or ammonia, which could be shipped as energy carriers or as final products. For example, ammonia could be used as a hydrogen-carrier, combustion fuel, or for fertilizer.

Note that achieving the third option would mean that energy and energy-products could be shipped to the USA from domestically-owned ocean thermal plantships at locations that are in many cases closer to our shores than are many of our (often hostile) foreign sources of imported oil.

A global map of the OTEC Thermal Resource to supply energy to the above markets

This map shows contours of annual average temperature differences, in degrees Celsius, available in the world’s major oceans between surface waters and the cold water at 1000 meters depth that serves as a heat sink. The most desirable regions (bounded by the areas in yellow) are where that parameter equals or exceeds 20 degrees Celsius.

Energy FROM the oceans, to replace energy from ACROSS the oceans!

  1. By Anonymous on March 8, 2010 at 1:17 pm

    A new Cost Effective OTEC based on Oil and Gas Deepwater Technology by DSI, Houston, Texas, USA. Dr. Nagan Srinivasan, PhD, PE, Please contact Naganus at yahoocom. DSI has made the OTEC cost effective with the modern deep water technology developments. Several innovations are introduced and the feasibility is successfully achieved. OTEC is 100% reliable and very stable plant. It occupies no land space and is designed to withstand 100 years hurricane with our innovative floating vessel. The thermodynamics, flow, pipeline, system design, vessel design had been achieved.
    1. 100 MW power plant will be supported by 50 people manned platform with helicopter access and quarters. It costs 450 million USD.
    2. 13 MW unit will have unmanned platform with boat landing options. It costs 70 million USD.
    3. Desalination could be much cheaper than the conventional.
    4. Desalination could be a by product along with power too.
    5. Hydrogen fuel can be produced

    We study of the ocean environment for suitability. We design the OTEC engine for that location. We design the supporting structure. We fabricate the vessel and install the OTEC plant. In the case of the desalination, we use water storage tank inbuilt with the supporting platform. In the case of the, ocean close tot he land, near shore with deep sea within the vicinity, we install land based OTEC power plant and desalination plant also.

    We own the proprietary of the technology and the drawings. We shall not give the detail drawings to the client. We subcontract detail engineering company and the fabricators. We purchase the equipments our self. We hire the installation company and we do the project management, procurements, vendor selection, pre commissioning. We take 5% for our licensing fee. Licensing is issued for each project and for each unit separately. We also maintain and repairs for the operation with additional charges. The maintenance and operational cost is very minimum. OTEC has tremendous future. The capital investment could be recovered within 10 years depend on the type of loan and interest. The government tax benefit and other In particular, DSI cost of building 100 mega watt unit power plants is almost equal to 10 mega watt unit of Lockheed Martin's, USA, OTEC power plant. DSI has considerably reduced the cost such that OTEC could be one of the prime sources of energy for the need of the world near equator.

    Corrosion, bio-fouling, platform mooring, survivability in severe storms, environmental concerns, working fluid leakages, safety issues, coupling of electrical cable to platform, power transmission through cable are all considered and resolved in our design. In general, Government of USA would consider tax credits to serve as an incentive/subsidy the 100% green energy, free of CO2. Thus the investor also could tax credit and government could fund partially to support this effort. This would make this OTEC power plant very attractive and the unit power price cost could reduce. The power plant could be highly profitable in compared to hydro, coal, nuclear, solar and wind based power plant. Considering no operational cost this is very attractive.

    The future of OTEC would turn into Hydrogen production platform. Excess electricity produced would be used to separate hydrogen from water with conventional method. Hydrogen fuel, hydrogen cells, hydrogen fuel cars etc are modern applications where the usage of petroleum fuel is reduced. There is a huge application behind in this line of industry that would develop after the power plant and potable water plant. In that case, the platform can be installed near equator where the OTEC could be more efficient round the year operation in common water and electricity can be produced. The Hydrogen can be produced and transported as compressed stage to land and then used for the car fuels and for hydrogen fuel cells. Please see the following website in glggroup for DSI on OTEC.

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