Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments 1.0 Executive Summary
1.5 Biomass and Municipal Solid Waste
Biomass project sizes from 5 to 30 MW were considered, and an optimum size of
20 MW was selected based on preliminary technical and economic analysis. The
biomass fuel mix and cost change based on the project size. Smaller projects can utilize
lower cost waste biomass resources (wood chips, bagasse, and cane trash), while larger
projects would need to rely on dedicated energy crops such as banagrass (elephant grass).
A stoker boiler was selected as the basis for the project conceptual design due to its good
mix of technical maturity, efficiency, and cost. The location for the biomass project has
not been specified yet.
After selecting 20 MW as the preferred size for the biomass project, capital and
O&M costs and plant performance were estimated to determine cost of energy for such a
plant for KIUC. The life-cycle costs were analyzed using the likely low, high and mid
range fuel costs to establish upper and lower bounds for the analysis. The results of these
estimates are shown in Table 1-1.
Table 1-1. Biomass Life-Cycle Economic Assumptions ($2005).
Unit
Low Fuel
Cost Mid Fuel Cost
High Fuel
Cost
Capacity MW 20.0 20.0 20.0
Capital Cost $/kW 4,556 4,556 4,556
First Year Fixed O&M $/kW-yr 150 150 150
First Year Variable O&M $/MWh 8.4 8.4 8.4
First Year Fuel Cost $/MBtu 3.50 4.15 4.57
Net Plant Heat Rate Btu/kWh 15,397 15,397 15,397
Capacity Factor percent 80% 80% 80%
KIUC Levelized Cost 2009$/MWh 179.5 194.8 204.6
KIUC Premium* 2009$/MWh 5.6 20.9 30.7
*Electricity cost premium (or savings) compared to KIUC’s forecasted avoided costs.
Based on the assumptions shown in Table 1-1, the levelized cost of electricity can
be calculated. The levelized electricity cost includes all costs to generate power (capital,
O&M, fuel, etc.) levelized over the life cycle of the project. In 2009, it is projected that
the levelized cost of supplying power from a biomass fueled power station would range
from $180/MWh to $205/MWh, depending on the fuel cost. This cost can be compared
to the cost of KIUC’s existing resources and projected new unit additions. These costs
would be “avoided” if the biomass plant were built. Based on avoided cost forecasts
from KIUC, biomass is able to avoid $174/MWh in energy and capacity costs on a
levelized basis (2009$). Taking these costs into account, the premium for biomass ranges
21 March 2005 1-9 Black & Veatch