Ocean thermal energy conversion gets one step closer to commercial reality

otecUPDATE: An interesting announcement from Lockheed Martin this morning. The military contractor says it has signed a “memorandum agreement” with real-estate developer Reignwood Group, founded and run by Thai-Chinese businessman Yan Bin, the second-richest man in Beijing. What have they agreed to do? Lockheed says it will design a 10-megawatt ocean thermal energy conversion (OTEC) plant, which will supply 100 per cent of the power needs of a planned “net-zero” green resort being built by Reignwood. “The agreement could lay the foundation for the development of several additional OTEC power plants ranging in size from 10 to 100 megawatts, for a potential multi-billion dollar value,” according to Lockheed in a press release.

This is exciting for two reasons. One, it’s very cool technology, and being an energy geek I love hearing this kind of news. Two, there’s huge potential here for the ocean to supply emission-free electricity around the world. Lockheed has been working on this technology since the 1970s. An OTEC power plant basically uses heat exchangers to extract heat out of the warmer upper ocean layers and create steam from a working fluid with a low boiling temperature, such as ammonia. As I wrote in my book Mad Like Tesla, “The steam would drive a turbine that generates electricity. Cold water from deeper layers would then be used to condense the ammonia back into fluid, at which point the cycle would be repeated.” In my book, I quoted Ted Johnson, director of alternative energy development at Lockheed, who is clearly optimistic about what the technology could offer. “I dream of thousands of floating OTEC ships roaming the seas of the world, providing an inexhaustible supply of clean energy and fuel and water for all people of the world.”

While Lockheed has been working on this for four decades, one of the first in-depth discussions of the concept came from Nikola Tesla, who at the age of 75 outlined how such a plant might be built in the December 1931 issue of Everyday Science and Mechanics journal. Tesla spent considerable time trying devising a way to improve the efficiencies of such a power plant, but he determined that it was too great an engineering challenge at the time. “I have studied this plan of power production from all angles and have devised apparatus for bringing down all losses to what I might call the irreducible minimum and still I find the performance too small to enable successful competition with the present methods,” he wrote, though still expressing hope that new methods would eventually make it possible to economically tap the thermal energy in oceans.

Lockheed is trying to demonstrate that the day has come. “Constructing a sea-based, multi-megawatt pilot OTEC power plant for Reignwood Group is the final step in making it an economic option to meet growing needs for clean, reliable energy,” said Dan Heller, vice-president of new ventures for Lockheed’s mission systems and training group. Lockheed said the technology is “well-suited” to island and coastal communities where — because of transportation logistics — energy prices tend to be high and there is great dependency on oil for power generation. “Unlike other renewable energy technologies, this power is also base load, meaning it can be produced consistently 24 hours a day, 365 days a year,” said Lockheed. “A commercial-scale OTEC plant will have the capability to power a small city. The energy can also be used for the cultivation of other crucial resources such as clean drinking water and hydrogen for applications such as electric vehicles.”

Continues Lockheed: “Once the proposed plant is developed and operational, the two companies plan to use the knowledge gained to improve the design of the additional commercial-scale plants, to be built over the next 10 years. Each 100-megawatt OTEC facility could produce the same amount of energy in a year as 1.3 million barrels of oil, decrease carbon emissions by half a million tons and provide a domestic energy source that is sustainable, reliable and secure. With oil trading near $100 a barrel, the fuel-savings from one plant could top $130 million per year.”

There is one point of confusion, however. Lockheed says this planned OTEC project — at 10 megawatts — will be the largest ever built, but I was under the impression it had designed or was in the process of designing a 10MW plant off the coast of Hawaii. I’ve e-mailed Lockheed asking for clarification on this and will update my post when I get an answer. For more background on this concept check out this story from a few months back by the folks at Greentech Media.

(UPDATE: I received a response from Lockheed spokesman Scott Lusk on the company’s work in Hawaii. Here’s what he had to say: “While Hawaii is one of the main places where Lockheed Martin has conducted research and evaluation around the OTEC technology, to date there have been no contracts awarded for commercial-scale OTEC development in the state. Lockheed Martin has tested the heat exchanger technology, a critical component in the OTEC plant design, at the NELHA research facility in Hawaii. In addition, Hawaii is one of several locations where Lockheed Martin has conducted feasibility studies. Other locations include Guam and Japan.”)

3 thoughts on “Ocean thermal energy conversion gets one step closer to commercial reality”

  1. This is very cool tech- and building platforms to withstand ocean swells and huricanes has been well-developed from the oil and gas industry- but I am curious as to what happens during a storm- does electricity get cut off from the platform? Does the resort then need to have backup generators for those situations?

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