Justin Heavey

The refereed literature contains few studies that analyze life cycle assessment (LCA) and techno-economic analysis (TEA) methodologies together for lignocellulosic bioenergy systems, using a stochastic modeling approach. This study seeks to address this gap by developing an integrated framework to quantify the environmental and financial impacts of producing and delivering shrub willow in the Northeastern United States. This study analyses four different scenarios from a combination of two different initial land cover types (grassland, cropland) prior to willow establishment, and two harvesting conditions (leaf-on, leaf-off). Monte Carlo simulations were performed to quantify the uncertainty of the results based on a range of financial, logistical, and biophysical variable input parameters (e.g., land rental rates, transportation distance, biomass yield, etc.). Growing willow biomass on croplands resulted in net negative GHG emissions for both leaf on and leaf off scenarios for the baseline. The GHG emissions were lowest for the leaf-off harvest on cropland (−172.50 kg CO2eq Mg−1); this scenario also had the lowest MSP ($76.41 Mg−1). The baseline grassland scenario with leaf-on harvest, results in the highest net GHG emissions (44.83 kg CO2eq Mg−1) and greatest MSP ($92.97 Mg−1). The results of this analysis provide the bioenergy field and other interested stakeholders with both environmental and financial trade-offs of willow biomass to permit informed decisions about the future expansion of willow fields in the landscape, which have the potential to contribute to GHG reduction targets and conversion into fuels, energy, or bioproducts for carbon sequestration and financial benefits.

Willow and poplar short rotation woody crops (SRWC) have shown promise with regards to environmental benefits and rural development but wide adoption lags due to underdeveloped markets and supply systems. High costs associated with harvesting, handling and transportation (40-60% of delivered cost) have impeded expansion. A better understanding of these systems will create opportunities to improve efficiency, reduce costs, and realize environmental benefits and impacts. The project’s goal was to lower the delivered cost of hybrid poplar in the Northwest and willow in the Northeast by optimizing harvesting and logistics supply systems while maintaining or improving biomass quality along the supply chain. Over 3,400 Mg of biomass and 300 ha of willow and poplar were monitored over a range of crop and field conditions. Feedstock quality as affected by storage and preprocessing were shown to improve or maintain feedstock quality. Modeled harvesting costs ranged from $38–61 Mg-1 dry; when including delivery and preprocessing feedstock costs ranged between $79-83 Mg-1 dry for willow and $106-116 Mg-1 dry for poplar. Costs for willow minimized when hot water extraction and high-moisture densification preprocessing were used. Models also suggest that social and regional factors could further reduce costs. Results will give guidance to feedstock growers, harvesting and logistic operations, biorefinery project developers, and policy makers developing SRWC to support a growing bioeconomy.

To increase the understanding of poplar and willow perennial woody crops and facilitate their deployment for the production of biofuels, bioproducts, and bioenergy, there is a need for broadscale yield maps. For national analysis of woody and herbaceous crops production potential, biomass feedstock yield maps should be developed using a common framework. This study developed willow and poplar potential yield maps by combining data from a network of willow and poplar field trials and the modeling power of PRISM-ELM. Yields of the top three willow cultivars across 17 sites ranged from 3.60 to 14.6Mgha(-1)yr(-1) dry weight, while the yields from 17 poplar trials ranged from 7.5 to 15.2Mgha(-1)yr(-1). Relationships between the environmental suitability estimates from the PRISM-ELM model and results from field trials had an R-2 of 0.60 for poplar and 0.81 for willow. The resulting potential yield maps reflected the range of poplar and willow yields that have been reported in the literature. Poplar covered a larger geographic range than willow, which likely reflects the poplar breeding efforts that have occurred for many more decades using genotypes from a broader range of environments than willow. While the field trial data sets used to develop these models represent the most complete information at the time, there is a need to expand and improve the model by monitoring trials over multiple cutting cycles and across a broader range of environmental gradients. Despite some limitations, the results of these models represent a dramatic improvement in projections of potential yield of poplar and willow crops across the United States.

EcoWillow 3.0S is a techno-economic analysis (TEA) tool that calculates realistic willow biomass production costs using data from field trials of willow production in New York State. The model represents the input parameters for diesel fuel price, wood price, and willow yield as data-derived probability distributions rather than as single values. This study uses EcoWillow 3.0S with Oracle Crystal Ball to perform a stochastic TEA of shrub willow production in the northeastern USA. Two outputs obtained from this model are a 24-year net present value (NPV) and minimum selling price (MSP) of shrub willow production under price and yield uncertainty. The MSP for dry willow ranges within a 95% confidence interval from $59-$102/Mg. The NPV, also within a 95% confidence interval, ranges from -$153 819 to $207 129 for 40 ha of willow harvested seven times over 24 years. The relevance of this study is to use the TEA methodology to assess the financial feasibility of shrub willow production as a bioenergy feedstock. The results of this analysis provide the bioenergy field with NPV and MSP probability distributions on shrub willow production that have previously been absent from the refereed literature. Using data collected from field operations over a number of years, EcoWillow 3.0S captures some of the key inputs that influence the variation in the delivered cost of willow biomass crops. (c) 2018 Society of Chemical Industry and John Wiley & Sons, Ltd

In this study, an integrated system of harvesting, collecting, and transporting willow biomass crop to a storage site was modeled and evaluated using the IBSAL simulation model. A scenario analysis was used to quantify the impacts of five major input parameters on the performance of the integrated system. These parameters include parcel size, field shape, willow yield, distance to the storage site, and type of the collection equipment. Multiple performance indicators were identified to quantify the impacts on the system such as size of the equipment fleet, effective material and field capacity of the harvester, operating costs, and waiting times. The input data were collected from 36 commercial, short-rotation, shrub willow fields in northern New York State. The simulation results indicated that crop yield and type of collection equipment have the highest impact on operating costs and the equipment fleet size. As the size of equipment fleet increases in the system, variability in the system performance tends to increase. Field shape has the least impact on the overall system performance compared to the other four input parameters. The simulation results suggest that a combination of performance indicators need to be considered to evaluate the overall performance of the dynamic and complex system of harvesting, collection and transportation in commercial willow fields. The developed IBSAL model and scenario analysis approach can assist in planning this system based on the characteristics of field, crop, and logistical equipment to reach a high system performance.

Blowing and drifting snow on roadways is a challenge in many cold-weather regions, especially those adjacent to large open fields with little or no vegetation or other obstructions to disrupt wind patterns. These areas are often remote from transportation maintenance facilities, and problems from blowing and drifting snow can persist for days or weeks after a snow event--closing roads and causing traffic delays. Constructed snow fences are often used to help keep snow from blowing onto the roadway. While these constructed fences work well, they serve only one capacity. An alternative is a "living snow fence" (LSF) which is composed of rows of trees or shrubs. The biomass from these plantings has the potential to be used for bioenergy and other purposes. Species such as poplar or willow can be particularly useful as a LSF, planted at low cost, and providing useful biomass. This publication provides details of willow LSFs being implemented in upstate New York and includes recommendations for other locations Includes bibliographical references (page 5).

Throughout the world, open land adjacent to industrial operations has been used to store byproducts of manufacturing and production processes. To minimize impacts on human health and the environment, these sites have traditionally been capped with clay or geomembrane materials to create a barrier to prevent the percolation of precipitation through the material and into the environment. Over the past two decades, the US EPA and others have experimented with vegetative covers, also known as evapotranspiration (ET) covers, as an alternative approach to address concerns at these sites while simultaneously providing a range of additional benefits. The purpose of this environmental application is to highlight the steps that are required to develop a plant-based solution to protect human health and the environment at a former industrial site. The project example used is the development of a willow vegetative cover on a former industrial site in New York State that was used to store the byproducts of soda ash production. Leaching of calcium and chloride salts into groundwater and nearby surface waters is the main environmental concern that must be managed. Includes bibliographical references (pages 6-7).

Poplar (Populus spp.) and willow (Salix spp.) are fast-growing trees and shrubs that can be used for a wide variety of environmental remediation and management purposes as well as provide biomass for bioenergy and bioproducts. Recent research in the U.S. has focused on growing these trees as short-rotation woody crops to provide biomass for renewable fuels and bio-based chemicals and products; however, domestic bioenergy markets have been inconsistent and the industry is still emerging. Although both poplar and willow have a long history of use for a variety of environmental purposes and bioenergy in Canada, Ireland, and other European countries, many barriers exist to similar implementation in the U.S. In April 2016, a National Working Forum was held in Portland, OR, to discuss how to bring together the environmental uses of poplar and willow with the production of biomass for fuel. This paper provides a summary of information and recommendations derived from the Forum including: (1) benefits, both environmental and otherwise, of growing poplar and willow and opportunities for using the biomass from these plantings, (2) barriers to this new endeavor, and (3) solutions to link biomass from poplar and willow grown for environmental applications to bioenergy markets. While use of poplar and willow for environmental benefits and biomass utilization is limited in the U.S., there have been successful programs, which are discussed in the Roadmap's supplemental Environmental Applications Series. A poplar- or willow-based system has the potential to be advantageous for landowners and others throughout the supply chain. This paper provides guidance towards the development of poplar and willow for environmental applications as well as a source of biomass for bioenergy. Includes bibliographical references (pages 34-36).

Landscape design has been embraced as a promising approach to holistically balance multiple goals related to environmental and resource management processes to meet future provisioning and regulating ecosystem services needs. In the agricultural context, growing bioenergy crops in specific landscape positions instead of dedicated fields has the potential to improve their sustainability, provide ecosystem services, and minimize competition with other land uses. However, growing bioenergy crops in sub-productive or environmentally vulnerable parts of a field implies more complex logistics as small amounts of biomass are generated in a distributed way across the landscape. We present a novel assessment of the differences in production and logistic costs between business as usual (BAU, dedicated fields), and distributed landscape production of shrub, or short-rotation willow for bioenergy within a US Midwestern landscape. Our findings show that regardless of the mode of cropping, BAU or landscape design, growing shrub willows is unlikely to provide positive revenues (-$67 to -$303 ha(-1) yr(-1) at a biomass price of $46.30 Mg-wet(-1)) because of high land rental costs in this agricultural region. However, when translated into a practice cost per unit of N removed at the watershed scale (range: $1.8-37.0 kg N-1 yr(-1)), the net costs are comparable to other conservation practices. The projected opportunity cost of growing willows instead of corn on underproductive areas varied between -$14 and $49 Mg-wet(-1). This highlights the potential for willows to be a cost effective choice depending on the intra-field grain productivity, biomass price and desirable concurrent ecosystem services. (c) 2016 The Authors. Biofuels, Bioproducts and Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.