Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments
3.0 Renewable Energy Technology
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Table 3-21. Ocean Thermal Energy Technology Characteristics.
On-Shore Off-Shore
Performance
Typical Duty Cycle Baseload Baseload
Net Plant Capacity, MW 10 100
Capacity Factor, percent
Economics
90 90
Capital Cost, $/kW 13,000-19,500 3,300-6,500
Variable O&M, $/MWh 17-33 17-33
Levelized Cost, $/MWh
Technology Status
140-220 53-103
Commercial Status Initial Demonstration Development
Installed US Capacity, MW 0 0
Kauai Potential Good Good
Environmental Impacts
There remain some important questions about the environmental impacts of
OTEC plants. The most frequently raised points are: changes to thermal, salinity, and
nutrient gradients within the vicinity; leakage of working fluid from CC-OTEC plants or
of the chlorine used for controlling bio-fouling; fatalities of small organisms such as
plankton; and the effects on fishing grounds.
Kauai Outlook
Several demonstration plants are currently under development, and these should
result in significantly more detailed and reliable cost and performance information within
the next five years. Commercial application of OTEC by utilities is unlikely until after
this time, but Hawaii is then a prime candidate for OTEC. Hawaii has some of the best
OTEC resources in the world. Current OTEC technology is not cost completive with
conventional power generation technologies; however, with continuing research and
demonstration, as well as added value services such as desalination and air conditioning,
this technology could become competitive in the long-term.
There have been no numerical estimates of the ocean thermal energy potential in
Hawaii; however, the potential is known to be very large and could easily support all of
the energy needs of the state. 35 Based on bathymetric data, on-shore plants could be
located on the southwest and southeast coasts of Hawaii, on the south coast of
35 State of Hawaii DBEDT, http://www.hawaii.gov/dbedt/ert/otec_hi.html, accessed July 2004.
21 March 2005 3-50 Black & Veatch