Biomass Feasibility Project Final Report - Xcel Energy

Processing Yard
Some biomass feedstocks may be shipped to a processing yard prior to shipment to a storage
facility or power plant. There are two general models for processing yards. The first would be a
local processing yard to which materials are hauled over a short distance and from which they
are hauled to a power plant or storage facility. An example of this would be a wood, or
“concentration.” yard that receives logging residues from nearby, chips them and loads them
for transport. The other model for a processing yard is one relatively close and accessible to the
power plant (and perhaps under its management), but not incorporated in to it. Sometimes
these processing yards serve plants that lack room on site for fuel processing or storage, as is the
case with two power plants in northern Minnesota that share a single processing yard located
midway between them. Such partnerships have the added advantage of capturing economies
of scale.
Storage Facility
Some biomass feedstocks will need to be stored at offsite storage facilities until they are needed
by the power plant. This is especially the case for biomass like switchgrass or corn stover ttthat
are harvested during a narrow window of time but are drawn down over the course of a year.
Fuel processing for storage may take place at the storage facility or somewhere else prior to
delivery. Storage facilities can take many forms, from open fields with stacks of uncovered bales
to large fully enclosed storage barns. To estimate storage costs one must estimate the capital
and handling costs associated with each storage method as well as the expected dry matter
loss associated with that method. Storing unprotected bales in the open requires no capital
expenditure and very little handling; but the loss of dry matter from such a storage method can
be quite significant.
Power Plant
Biomass fuel ultimately must be shipped to the power plant. Once on site, the fuel may go into
storage bins or proceed directly into the plant’s fuel feeding system. Final processing steps often
include screening and size reduction. Default costs for transport to the plant, processing and
unloading are provided, or the user can enter more specific costs if they are available.
The evaluation tool is designed to allow the user to develop different “scenarios” that can be
combined later to evaluate different options. There are three scenario types: Feedstock, Power
Plant, and Project. The Project Scenario is comprised of a combination of the first two.
Scenario Generation
Feedstock Scenario
The development of a feedstock scenario allows the user to build a feedstock development and
delivery system ending with a cost per MMBTU for a fully-processed fuel at the power plant. You
may make as many Feedstock Scenarios as you wish. All Feedstock Scenarios must be logged if
they are to be used for future analysis.
Power Plant Scenario
The development of a power plant scenario allows the user to define the characteristics of an
operating power plant. This includes such things as power plant size, capital costs, operating
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Identifying Effective Biomass Strategies:
Quantifying Minnesota’s Resources and Evaluating Future Opportunities