P.I.: Assoc. Prof. Gerard Nihous, Department of Ocean and Resources Engineering
Objective: (i) Document the ocean thermal resource; and (ii) Analyze OTEC potential for degradation of the thermal resource.
Presently: It has been recognized that closely spaced commercial OTEC systems can interfere and alter the ocean temperature profile with a resulting drop in performance and possible negative environmental consequences. In addition, our analysis shows that global OTEC resources are limited by the rate of deep cold seawater formation in Polar Regions.
One might ask: is OTEC renewable energy? The simple answer is that as long as the sun shines and, if and only if, deep-ocean cold water is provided by the thermohaline circulation the ocean thermal resource is renewable. A pertinent question, however, is: what is the worldwide power resource that could be extracted with OTEC plants without affecting the thermohaline ocean circulation? Our estimate is that the maximum steady-state OTEC electrical power is about 5 TW (e.g., 50,000x 100 MW OTEC plants!) This is about twice the amount projected for worldwide consumption by 2025. This estimate is documented on a paper published in 2007 {Updated Extractable Ocean Thermal Resources (2007)} updating a simpler model published in 2005 {Extractable Ocean Thermal Resources (2005)}.
Project: The effects of OTEC will be investigated through numerical modeling to address the issue of degradation and global sustainability of the OTEC resource.
Averages of temperature differential (° C) between surface waters (heat source) and waters from 1,000 m depths (heat sink) for February and August are depicted in the following Figures. Values are color coded as indicated in the right-hand-side of the Figures (double left hand click). Prof. Nihous used information from the National Ocean Data Center’s World Ocean Atlas (2005 version) to generate the world wide representation of historical monthly averages. The daily averages off Hawaii were mapped combining ocean data assimilation models (HYCOM/NCODA).
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- World Wide Monthly Averages February 2005
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- World Wide Monthly Averages August 2005
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- Feb 1, 2009 Daily Average off Hawai'i
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- August 3, 2008 Daily Averages off Hawai'i
Great Site !
Just a small point.
It would be useful, later, to know the colour coding of the World Wide Monthly Average Temperatures.
Aloha Energy Island, if you click on the Figure (photo) to enlarge display you will see temperature color scale
Great presentation. Interesting how the thermocline shifts Northward in Summer months so that the Northern Kauai has a higher temperature potential than does Hawaii! Thanks Luis.
Straight to the point and well written, thanks for the information