Biomass Feasibility Project Final Report - Xcel Energy

$0.140
$0.120
No Benefits
$0.100
$/kWh
$0.080
$0.060
$0.040
Benefits Included
$0.020
$0.000
Figure X-1: Comparison of Anaerobic Digesters
OPPORTUNITY 8: ELECTRIC-ONLY POWER PLANTS
Electric-only power plants fueled by biodiesel are likely to be the least cost-effective type of
biomass power plants. This is largely due to the fact that such facilities would be expensive
baseload facilities burning expensive fuels. There are two options for electric-only biomass
plants: direct combustion and gasification.
Direct combustion electricity-only. Of all available options, direct combustion plants would
generate the most expensive biomass power. Capital and fuel costs would be high, and
combustion boilers inefficient. Size constraints imposed by costs of collecting and transporting
biomass would prevent them from taking advantage of economies of scale important in
baseload facilities.
Gasification electricity-only. Gasification technologies are more promising than direct
combustion technologies for generating electricity because they offer a wider range of
applications. They can be used in conjunction with combined-cycle facilities, combustion
turbines, gensets or simple syngas-fired boilers. If gasifiers become less costly, their compatibility
with downstream technologies like these will make them the obvious choice for many biomass
power plants in the years to come.
OTHER CHP OPPORTUNITIES
A number of studies have examined prospects for developing combined heat and power plants
in general, and some have considered their development in Minnesota in particular. Typical
candidates exhibit large, relatively constant thermal and electrical demands and a low power
to heat ratio.
One study (Minnesota Planning, 2001) which has proven prophetic, found that, at the time of its
writing, the four most attractive prospects among Minnesota’s industrial and commercial
facilities were Rahr Malting, Chippewa Valley Ethanol, the Duluth Steam Cooperative and St.
Mary’s Duluth Clinic Health Systems. Rahr now is building a biomass-fired CHP system and
Chippewa is developing a biomass gasification project.
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Identifying Effective Biomass Strategies:
Quantifying Minnesota’s Resources and Evaluating Future Opportunities