The energy requirements for construction and operation of an OTEC system are estimated. The conceptual system selected for analysis was one developed by Lockheed Missiles and Space Company. It uses a Rankine power cycle with ammonia as the working fluid, and is based on essentially available technology. The plant would be located about 20 miles offshore and would produce 160 MW(e) of net electricity that would be carried ashore by underwater cable for transmission and distribution by conventional means. Evaporators and condensors for the ammonia power cycle were assumed to be made of titanium (for resistance to corrosion) although it is recognized that aluminum alloys--preferable from a cost standpoint--may prove to have acceptable corrosion resistance. Net electrical output of the plant at an assumed 90% plant factor is 1.26 x 10 exp 9 kWh(e) per year. Annualized energy inputs for construction and operation (including periodic repair and replacement of major plant components) are estimated to be 15 x 10 exp 6 kWh of electricity and 37 x 10 exp 10 Btu of direct or indirect fuel consumption not associated with the electricity inputs. Thus the electrical energy "subsidy" represents about 1% of net station output, while non-electric energy subsidies add up to approximately 300 Btu per kWh(e). If the electrical energy inputs are assumed to come from fossil-fueled plants with an overall energy requirement of 13,850 Btu per net kWh(e), then the overall energy subsidy is about 58 x 10 exp 10 Btu per year. The delivered energy from the OTEC plant is thus nearly 7 to 10 times the direct and indirect primary energy inputs. Therefore, this OTEC system would return useful energy far in excess of the energy inputs required for its construction and operation. (ERA citation 02:051233)

  • Corporate Authors:

    Institute for Energy Analysis

    Oak Ridge, TN  United States 

    Energy Research and Development Administration

    20 Massachusetts Avenue, NW
    Washington, DC  United States  20590
  • Authors:
    • Perry, A M
    • Marland, G
    • Zelby, L W
  • Publication Date: 1977-2

Media Info

  • Pagination: 55 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00169598
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Contract Numbers: EY-76-C-05-0033
  • Files: TRIS
  • Created Date: May 18 1978 12:00AM