The costs given in this section are presented without supporting detail. They were calculated using the procedures given in the ASABE Machinery Management Standard [3]. They are “best estimates” given current cost parameters. It is unlikely significant $/h cost reductions can be achieved for the various machines. All costs are given on a $/dry ton basis for operation of a bioenergy plant consuming 23 dry ton/h. The real challenge is to find a way that machine productivity (tons/operating hour) can be increased.

Some additional detail on the functionality of the various unit operations in the rack system logistics chain is given in Appendix 13.B. This detail will benefit those who

want a better understanding of the opportunities for improved productivity in individual operations.

13.9.1 Truck Cost Excluding Fuel

The assumed truck cost (tractor and trailer for hauling the two racks) is $630/d for a 24-h workday, which includes ownership plus operating cost, plus labor, but excluding fuel. Truck cost, excluding fuel, is:

$630/d

11.5 loads/d x 12.2 dry ton/load

13.9.2 Truck Fuel Cost

Fuel cost for the 25.4 mi average haul distance is

(25.4 mile x 2)/(4 mile/gal) = 12.7 gal x $3.50/gal

$44.45/load

12.2 dry ton/load

13.9.3 Total Truck Cost

Total truck cost is:

Ownership and operating + Fuel = Total

4.49 + 3.64 = $8.13/dry ton

13.9.4 Load, Unload Operations

1. Handling racks at plant — 1.93 (workhorse forklift) + 1.02 (backup forklift) = $2.95/ dry ton

2. SSL operation — 3.66 (telehandler) + 0.98 (extra trailers) = $4.64/dry ton

3. Rack cost — cost of 230 racks = $1.80/dry ton

4. Storage yard at processing plant — $0.13/dry ton

5. Conveyor entering plant — $0.28/dry ton.

13.9.5 Size Reduction

Unroller-chopper — $5.76/dry ton

The costs given in Table 13.1 are grouped as follows:

Rack cost — All costs associated with the ownership and maintenance of the racks. Loading cost — All costs associated with the loading of bales into racks. These costs are referred to as “SSL operation costs”.

Truck cost — All costs associated with the ownership and operation of the trucks. Receiving Facility cost — All costs associated with the unloading of racks from trucks, placement of racks onto conveyor (or placement in at-plant storage), conveyor operation, operation of at-plant storage, and removal of racks from at-plant storage and placement on trucks for return to SSL.

Size reduction — All costs associated with the unloading of bales from the rack, operation of conveyor for single file delivery of bales to a size reduction machine, and operation of machine for initial size reduction.

Costs are as follows: truck (34%), SSL operations (20%), receiving facility operations (14%), size reduction (24%), and racks (8%). It is clear why the Rack System Concept was organized to maximize truck productivity — truck cost is the largest cost component. Truck cost plus SSL operations are $12.77/dry ton, or 54% of total cost. The receiving facility cost is $3.37/dry ton, only 14% of total cost. As with all other multibale handling system concepts, the Rack System Concept provides an opportunity for minimizing cost between the plant gate and the size reduction unit operation.

The total cost shown in Table 13.1 does not include the farmgate contract cost (production, harvesting, in-fleld transport, storage in SSL, profit to producer). The farmgate contract cost can be estimated from local data for production, harvest, and ambient storage of round bales of hay. In the Southeast United States, the key issue relative to the hay cost comparison is the difference in yield — switchgrass will yield about 4 ton/acre as compared to traditional hay species that yield about 2 ton/acre.