New York State’s (NYS) Climate Leadership and Community Protection Act (CLCPA) requires that 100% of the state’s electricity supply be greenhouse gas emissions-free by 2040 and that 6000 megawatts (MW) of solar energy must be installed in NYS by 2025. This study aims to evaluate the environmental impact of electricity generation from New York State distributed solar photovoltaic systems. This cradle-to-grave life cycle assessment (LCA) follows the International Standardization Organization (ISO) framework for LCA, including the goal and scope definition, inventory analysis, impact assessment, and interpretation. The study is based on operational data from 120 existing solar installations. Global Warming Potential varies substantially by site, with the minimum and maximum impact values varying from 25.2 to 88.5 gCO2eq/kWh, and with a mean of 45.6 gCO2eq/kWh. Regression analysis shows this range is attributable to differences in site location, capacity factor, and system design (i.e., monocrystalline and polycrystalline panels, area power ratio). Based on absolute percentage, the inclusion of the end-of-life process reduces the total environmental impact from 2% in Ozone Depletion to 16% in Acidification, indicating a positive impact of engaging in end-of-life management across all categories. This analysis can help policymakers understand the implications of the solar PV installation mandate.
Shrub willow (Salixspp.) is capable of producing commercially attractive amounts of biomass in short rotations, but harvesting costs and logistics remain a concern. There is a particular need for information about harvesting operations on larger, commercial short‐rotation woody crop systems. Another recent issue on commercial fields in northern New York is commercial growers conducting harvests during the growing season rather than the recommended dormant season when fields may be too wet to harvest. This study evaluated and modeled the in‐field performance of a cut‐and‐chip harvester for almost 700 wagonloads of chips operating in commercial willow fields in a wider array of crop and field conditions than have been previously reported. Analysis indicated that the time of harvest (leaf‐on or leaf‐off) and whether site conditions were wet or dry affected the harvester's material capacity. Mean material capacity was greatest for leaf‐off, dry conditions (71.8 Mg/hr) and lowest for leaf‐on harvests, which were similar for wet (30.4 Mg/hr) and dry conditions (29.7 Mg/hr). Mean crop specific fuel consumption ranged between 1.3 and 3.3 L/Mg, but can get considerably higher for standing biomasses below 40 Mg/ha. Wet ground conditions and leaf‐on harvests tend to decrease material capacity and increase fuel consumption as the harvester has to divert power to forward movement and material processing. Relationships for material capacity and fuel consumption based on standing biomass, time of harvest and ground conditions will be essential for evaluating and modeling the economic and environmental impacts of commercial‐scale willow operations.
Short-rotation woody crops (SRWC) have the potential to make substantial contributions to the supply of biomass feedstock for the production of biofuels and bioproducts. This study evaluated changes in the fuel quality (moisture, ash, and heating value) of stored spring harvested shrub willow (Salix spp.) and hybrid poplar (Populus spp.) chips with respect to pile protection treatments, location within the storage piles, and length of storage. Leaf-on willow and poplar were harvested in the spring, and wood chips and foliage with moisture content in the range of 42.1% to 49.9% (w.b.) were stored in piles for five months, from May to October 2016. Three protection treatments were randomly assigned to the piles. The control treatment had no cover (NC), so piles were exposed to direct solar radiation and rainfall. The second treatment had a canopy (C) installed above the piles to limit direct rainfall. The final treatment had a canopy plus a dome aeration system (CD) installed over the piles. Covering piles reduced and maintained the low moisture content in wood chip piles. Within 30 days of establishment, the moisture content in the core of the C pile decreased to less than 30%, and was maintained between 24%–26% until the end of the storage period. Conversely, the moisture content in the NC piles decreased in the first two months, but then increased to the original moisture content in the core (>45 cm deep) and up to 70% of the original moisture content in the shell (<45 cm deep). For all the treatments in the tested conditions, the core material dried faster than the shell material. The higher heating value (HHV) across all the treatments increased slightly from 18.31 ± 0.06 MJ/kg at harvest to 18.76 ± 0.21 MJ/kg at the end of the storage period. The lower heating value (LHV) increased by about 50% in the C and CD piles by the end of the storage period. However, in the NC piles, the LHV decreased by 3% in the core and 52% in the shell. Leaf-on SRWC biomass stored in piles created in late spring under climatic conditions in central and northern New York showed differing moisture contents when stored for over 60–90 days. Overhead protection could be used to preserve or improve the fuel quality in terms of the moisture content and heating value if more than two months of storage are required. However, the implementation of such management practice will depend on whether the end users are willing to pay a higher price for dryer biomass and biomass with a higher LHV.