Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments
3.0 Renewable Energy Technology
Options
typically contain only trace amounts of toxic metals, such as mercury, cadmium, and
lead.
On the other hand, biomass combustion still must cope with some of the same
emissions issues as larger coal plants. Primary pollutants are nitrogen oxides, particulate
matter, and carbon monoxide. Standard air quality control technologies are used to
manage these pollutants.
Kauai Outlook
There is very good potential for power production from biomass combustion in
Kauai. Until recently, the island has generated a significant portion of its power from
bagasse, the fibrous residue from sugarcane. Gay & Robinson, the only remaining sugar
plantation, supplies a small amount of power to KIUC. Unlike most other renewable
energy options, the past experience with bagasse indicates that the island has not only the
potential biomass, but also the human resources and technical know-how to staff and
successfully operate a biomass plant. Further, the recent closure of the Lihue bagasse
fired power plant may represent a unique opportunity to salvage equipment for reuse in a
new or refurbished biomass plant.
Kauai’s biomass resources are diverse. A survey of existing biomass resources
was recently competed for the DBEDT. 4 The survey results for Kauai are summarized in
Table 3-2.
As shown in the table, residues from sugar production (bagasse and cane trash)
currently comprise the largest biomass resource on the island. However, Gay & Robinson
is exploring alternative uses for their bagasse, including ethanol production. In addition,
the future of sugar production on the island is quite uncertain, making exclusive reliance
on sugar residues unwise. The other major existing resource identified in the study is
municipal solid waste, which is discussed more thoroughly in Section 3.4. The existing
biomass and waste resources identified in the study represent a moderate potential source
of energy. If used in a single baseload plant of about 17 MW, they could generate about
200 GWh/yr of energy. Black & Veatch also surveyed the island for other sources of
biomass waste not identified in the study. These include residues from corn, coffee, and
guava production. Available quantities appear somewhat limited, but further
investigation is warranted if biomass passes the screening phases.
4 University of Hawaii, Hawaii Natural Energy Institute, “Biomass and Bioenergy Resource Assessment
State of Hawaii”, available at: http://www.hawaii.gov/dbedt/ert/biomass-assessment.pdf, December 2002.
21 March 2005 3-7 Black & Veatch