Renewable Energy Technology Assessments - Kauai Island Utility ...

Kaua’i Island Utility Cooperative
Renewable Energy Technology Assessments 3.0 Renewable Energy Technology Options
Applications
Most fuel cell installations are less than 1 MW. Commercial stationary fuel cell
plants are typically fueled by natural gas, which is converted to hydrogen gas in a
reformer. However, if available, hydrogen gas can be used directly. Other sources of
fuel for the reformer under investigation include methanol, biogas, ethanol, and other
hydrocarbons.
In addition to the potential for high efficiency, the environmental benefits of fuel
cells remain one of the primary reasons for their development. High capital cost, fuel cell
stack life, and reliability are the primary disadvantages of fuel cell systems and are the
focus of intense research and development. The cost is expected to drop significantly in
the future as development efforts continue, partially spurred by interest by the
transportation sector.
Performance and Cost Characteristics
The performance and costs of a typical fuel cell plant are shown in Table 3-38. A
significant cost is the need to replace the fuel cell stack every 3 to 5 years due to
degradation. The stack alone can represent up to 40 percent of the initial capital cost.
Most fuel cell technologies are still developmental and power produced by commercial
models is not competitive with other resources. For reference, the price of fuel is
assumed to be $12/MBtu, which is equivalent to diesel at $1.66/gallon. A price of
$0/MBtu is also modeled, should a source of waste hydrogen be available.
Table 3-38. Fuel Cell Technology Characteristics
Commercial Status Development / Early Commercial
Performance
Net Capacity per Unit, kW 100-250
Net Plant Heat Rate, Btu/kWh 7,000-9,500
Capacity Factor, percent 30-70
Economics
Capital Cost, $/kW 6,000-8,400
Fixed O&M, $/kW-yr * 650-910
Variable O&M, $/MWh 7-13
Levelized Cost, $12/MBtu Fuel, $/MWh 421-589
Levelized Cost, $0/MBtu Fuel, $/MWh 308-435
* Notes: Includes costs for cell stack replacement every four years.
21 March 2005 3-85 Black & Veatch