Systems Informatics and Analysis - Engineering and Science of Biomass Feedstock Production and Provision - page 214

baseline [ 109 ]. The goal of the model is to study the policy decisions in agriculture by
accounting for the environmental and social impacts in addition to farming practices
and crop production. The model is an integration of a variety of self-contained mod-
ules, representing different sectors such as regional crop supply, national livestock,
national crop demand, national income (IMPAL model), and regional environmental
impact (EPIC model). The model considers three different energy crops, switchgrass,
hybrid willows, and hybrid poplars, in addition to conventional crops and livestock
farming. The lower 48 states of the USA are divided into 305 geographical regions
based on similarity of the production characteristics. The core of the model focuses
on making agricultural decisions such as crop selection, crop rotation, and acreage
allocation. Simulation horizon ranges from 5 to 25 years. Walsh et al. [ 110 ] imple-
mented the POLYSYS modeling framework to conduct an economic analysis of the
development of the bioenergy market and its implications on the traditional crop
prices and farm income. Kszos et al. [ 111 ] used the POLYSYS model in combination
with another model (BIOCOST) that allowed one to study the effect of changes in
yield, management practices, and rate of plant maturation of the bioenergy crops on
the production cost and consequent effects on the agricultural sector.
Khanna et al. [ 15 ] determined the break-even price for Miscanthus and switch-
grass in Illinois by using yield data from MISCANMOD and farm operations and
transport cost from the literature. They reported a break-even farm-gate price for
Miscanthus between $41 and 58 ton −1 and the price at the gate of the power plant to
be between $44 and 80 ton −1 . Although these prices were better than those for
switchgrass, they were considerably higher than the price of coal, indicating that
strong policy incentives were needed to make biomass attractive. Jain et al. [ 53 ]
extended that work to a larger Midwestern US region by using MISCANMOD that
was parameterized based on observed yield data. The break-even price ranged from
$88 to 188 ton −1 for switchgrass and $53 to 243 ton −1 for Miscanthus. It must be
noted that these analyses take an economics-based approach by considering the
land opportunity cost due to conventional crops such as corn. The operational
aspects of feedstock production and provision were not considered in much detail,
and values reported in the literature were used. Both these articles report a number
of sensitivity studies that provide additional insights. Recently, Khanna et al. [ 112 ]
have extended this work to develop a model called Biofuel and Environmental
Policy Analysis Model (BEPAM). It is a dynamic, nonlinear mathematical pro-
gramming model considering multimarket equilibrium. The scope of this model is
therefore similar to that of POLYSYS. It determines land allocation, crop produc-
tion, and crop prices in the market for fuel, biofuel, food and feed crops, and live-
stock. The model performs yearly simulations from 2007 to 2030 for the USA. The
model has been used to simulate scenarios for different crop prices and study their
impact on land allocation. For each scenario, the distribution of land allocated to
different crops among the 295 crop rotation districts was identifi ed. Such data
become extremely valuable to identify likely biorefi nery locations and provide
incentives. Additionally, more detailed engineering models such as BioFeed
and IBSAL can be applied to regions identifi ed here to generate more accurate
estimates of production costs.