Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments 7.0 Biomass and Municipal Solid Waste
7.0 Biomass and Municipal Solid Waste
Biomass and waste-to-energy (WTE) power plants use substantially similar
technologies. In the case of Kauai, it is possible that the best economies of scale for a
solid fuel combustion project will occur by combining the two fuels in a common project.
This is not typical in most locations, but constrained fuel resources make this a
reasonable option to consider. This section, therefore, will combine the two fuels and
technologies with alternately separate and combined discussion of plant configurations,
as appropriate.
7.1 Basis for Assessment
The Interim Report identified typical biomass and WTE generation technologies.
The understanding and basis for these characterizations come from Black & Veatch’s
extensive history of designing and constructing these plants.
This section presents multiple options for biomass or WTE plants. Determining
which best suits KIUC’s needs is a matter of understanding plant performance and cost,
economies of scale, fuel supply, and operation and maintenance requirements. These
issues can be resolved into the following questions:
• On a busbar cost basis, is it better to build a small plant burning low cost
residue; or a larger, more efficient plant burning more expensive fuel?
• What are the options for combining biomass and WTE fuels in terms of
common plant facilities?
These questions will be answered in the Project Options Screening, and the
preferred sizes and configurations will be characterized in the remainder of the section.
Based on our design experience, we have made several assumptions regarding
plant performance. These are the following:
Table 7-1. Biomass and WTE Plant Performance Assumptions.
Ambient Conditions
Pressure, psia 14.6
Average Temperature, F 85
Relative Humidity, percent 60.1
Boiler Efficiency, percent 70
21 March 2005 7-1 Black & Veatch