Jenny Frank

Underutilized biomass resources offer significant potential to support low-emissions energy goals. Grape pomace, the primary waste from winemaking, is a promising feedstock for anaerobic digestion due to its favorable biochemical composition and potential to produce biogas and digestate. However, this specialty crop residue continues to be treated as homogeneous in makeup, despite evidence suggesting that grape pomace can vary greatly depending on variety and region of origin. In turn, these differences in grape pomace composition can directly influence the economic outcomes for farmers pursuing on-farm anaerobic digestion. However, researchers lack consensus on a consistent definition of grape pomace, limiting its connection to industry practice. This communication identifies three barriers to wider adoption: regional limitations of grape pomace anaerobic digestion, poor methodological standardization across studies, and a lack of economic feasibility analyses grounded in measured feedstock data. Key findings include evidence of biochemical methane potential results ranging from 52 to 280 NL CH₄/kg VS, with anaerobic biodegradability spanning 29.7% to 69.0% depending on variety, origin, and treatment conditions. Additionally, grape pomace does not typically adhere to the International Organisation of Vine and Wine’s own definition of grape pomace, and studies have included any form of grape pomace from just the skins and pulp to skins, seeds, pulp, and stems, yet this variation can lead to varying levels of biochemical methane potential. Furthermore, while on-farm anaerobic digestion of grape pomace has shown potential, studies tend to neglect how feedstock compositional variability across varieties and regions translates into conflicting economic viability.

The continued growth of global greenhouse gas emissions in the wake of the 2015 Paris Agreement has prompted policymakers to increasingly examine carbon dioxide removal strategies as a means of reducing the atmospheric CO₂ concentration and thereby avoiding the worst effects of climate change. Direct air capture technologies remain at a very early stage of deployment, however, prompting the policy community to turn to biochar production as a carbon dioxide removal strategy with near-term net sequestration potential. This chapter (1) reviews how biochar has been covered by energy and climate policy historically; (2) examines how biochar is contributing to recent deep decarbonization policies; and (3) considers how biochar may participate in policies implemented in the future.

New York State (NYS) has set strict greenhouse gas (GHG) emission reduction targets across all sectors of its economy, including the heating sector. This study examines the financial value and environmental impacts of the residential space heating sector in NYS under different GHG abatement options by comparing the existing natural gas heating pathway with three potential GHG abatement pathways: renewable natural gas (RNG), hydrogen blended into RNG, and air-source heat pumps (ASHPs). These pathways are analyzed via a comparative net present value (NPV) framework from 2022 to 2042 with the emission reduction represented as a revenue stream that serves as a function of the social cost of GHGs. The investment timing of each of these pathways is also accounted for to reflect the pathways’ varying deployment timelines. The ASHP pathway with a 10% financial discount rate and a 2% social cost of the GHG discount rate achieves the lowest NPV. The RNG pathway achieves the highest NPV. A sensitivity analysis determines the impact of key factors on the NPV results. This study aims to inform policymakers, homeowners, and stakeholders of the potential benefits and costs of each of the four pathways to aid them in their decision-making process.

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 CO_2eq 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 CO_2eq 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.

The Indian Point Energy Center (IPEC) supplied approximately 25% of New York City and the surrounding area’s electricity. As of April 2021, the nuclear power plant has been shut down, creating the need for other energy sources to meet the demand. This scoping analysis study examined the ability of different renewable pathways (solar photovoltaic (PV), willow biomass, onshore wind, and two combinations of these) to replicate the IPEC’s electricity generation profile. Five renewable electricity generation supply profiles were developed and analyzed from monthly and seasonal perspectives. The timing and alignment of the different generation supply profiles relative to that of IPEC were analyzed. Productivity in MWh hectare⁻¹ year⁻¹ and economic feasibility of the renewable electricity pathway scenarios were assessed. This study identified the solar PV pathway as the most efficient in terms of electricity land productivity at 731.9 MWh hectare⁻¹ year⁻¹, while the willow biomass pathway was the least efficient at 15.2 MWh hectare⁻¹ year⁻¹. However, in terms of net electricity output to the grid, the solar PV pathway was the least productive at 137,610 MWh/year, while the onshore wind with willow biomass pathway produced the highest net output at 894,801 MWh/year. These findings are important at a time when policymakers are considering or implementing plans to phase out nuclear power in favor of renewable electricity.

There is a lack of economic feasibility analyses on the harvesting of forest biomass to supply low‐carbon bioenergy feedstocks using actual data on the mixed product harvest in the hardwood region of the northeast USA. This study is a techno‐economic analysis of three different scenarios (clean chips, dirty chips, or pulpwood) based on data collected from whole‐tree harvesting systems over 6 years. Each scenario had two different cases: one with costs and revenues allocated by mass (allocated system), and the other without allocation (whole system). The six cases of three scenarios tested resulted in a wide range of positive net present values (NPVs) from $1 713 000 to $819 in US dollars. Clean chip production generated substantial NPVs and dirty chips generated marginal NPVs. The minimum selling prices (MSPs) of clean chips from two cases were similar, $45.92 and $45.55 per green metric ton (Mg), with maximum hauling distances (MHDs) of 247 and 250 km (km). The MSPs for dirty chips from four cases ranged from $34.38 to $37.47 per Mg with the range of MHDs from 184 to 351 km. MSP and sensitivity analyses suggest that the selling prices and harvesting production levels of clean chips and dirty chips, and purchase prices of forestry logging equipment are the key factors that most influence the profitability of the regional forest biomass feedstock supply chain. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd