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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basin behind the dam is filled to capacity. After the ocean waters have receded, the tidal
basin is released through a turbo-generator in the dam. Power may be generated during
ebb tide, flood tide, or both.
Resource Availability
Tidal power is typically used as an intermediate generation source for utilities
because of the intermittent, although predictable, nature of the tidal resource. The
capacity factor of tidal energy facilities may be expected to be around 25 percent. A few
utility-scale facilities have been developed around the world. The largest facilities are a
240 MW plant in France and an 18 MW plant in Canada.
Times and amplitudes of high and low tide are predictable, although these
characteristics will vary considerably by region. Economic studies suggest that tidal
power will be most economical at sites where mean tidal range exceeds about 16 feet. In
the US, these conditions only exist is Maine and Alaska, which precludes the rest of the
country, including Hawaii, from the economic generation of power from this resource.
Cost and Performance Characteristics
Costs to develop a tidal energy facility are extremely site-specific, and can vary
considerably. Table 3-25 presents a range typical performance and cost characteristics
for tidal energy plants.
21 March 2005 3-56 Black & Veatch