The neglected social dimensions to a vehicle-to-grid (V2G) transition: a critical and systematic review

Vehicle-to-grid (V2G) refers to efforts to bi-directionally link the electric power system and the transportation system in ways that can improve the sustainability and security of both. A transition to V2G could enable vehicles to simultaneously improve the efficiency (and profitability) of electricity grids, reduce greenhouse gas emissions for transport, accommodate low-carbon sources of energy, and reap cost savings for owners, drivers, and other users. To understand the recent state of this field of research, here we conduct a systematic review of 197 peer-reviewed articles published on V2G from 2015 to early 2017. We find that the majority of V2G studies in that time period focus on technical aspects of V2G, notably renewable energy storage, batteries, or load balancing to minimize electricity costs, in some cases including environmental goals as constraints. A much lower proportion of studies focus on the importance of assessing environmental and climate attributes of a V2G transition, or on the role of consumer acceptance and knowledge of V2G systems. Further, there is need for exploratory work on natural resource use and externalities, discourses and narratives as well as social justice, gender, and urban resilience considerations. These research gaps need to be addressed if V2G is to achieve the societal transition its advocates seek

Exploring impacts of process technology development and regional factors on life cycle greenhouse gas emissions of corn stover ethanol

This paper examines impacts of regional factors affecting biomass and process input supply chains and ongoing technology development on the life cycle greenhouse gas (GHG) emissions of ethanol production from corn stover in the U.S. Corn stover supply results in GHG emissions from -6 gCO2eq./MJ ethanol (Macon County, Missouri) to 13 gCO2eq./MJ ethanol (Hardin County, Iowa), reflecting location-specific soil carbon and N2O emissions responses to stover removal. Biorefinery emissions based on the 2011 National Renewable Energy Laboratory (NREL) process model are the single greatest emissions source (18 gCO2eq./MJ ethanol) and are approximately double those assessed for the 2002 NREL design model, due primarily to the inclusion of GHG-intensive inputs (caustic, ammonia, glucose). Energy demands of on-site enzyme production included in the 2011 design contribute to reducing the electricity co-product and associated emissions credit, which is also dependent on the GHG-intensity of regional electricity supply. Life cycle emissions vary between 1.5 and 22 gCO2eq./MJ ethanol (2011 design) depending on production location (98% to 77% reduction vs. gasoline). Using system expansion for co-product allocation, ethanol production in studied locations meet the Energy Independence and Security Act emissions requirements for cellulosic biofuels; however, regional factors and on-going technology developments significantly influence these results

Life cycle assessment (LCA) and life cycle costing (LCC) of road drainage systems for sustainability evaluation:Quantifying the contribution of different life cycle phases

Previous Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) studies on urban drainage systems only included construction materials in the system inventories. The present study aims to suggest an LCA and LCC method that for the first time, considers the inventories from four main phases in the life cycle impact assessment, including extraction of aggregates and production of construction blocks, transportation, construction, civil work and finally maintenance and end-of-life. LCA and LCC were carried out for 10 drainage systems including filter drains, infiltration trenches, soakaways, permeable pavement, infiltration basin, wetland, retention ponds, swales, filter strip, kerb and gully. Results showed that normalisation of environmental impacts and costs to drainage system size (length or area) was more appropriate for drainage systems with higher flow rate capacities (e.g., kerb and gully). However, drainage systems with low flow rate capacities that were designed to store runoff, required normalisation of environmental impacts and costs to storage capacity. The environmental impacts associated with urban drainage systems that needed considerable amounts of virgin aggregates (e.g., filter drains) were higher than those with limited construction material (e.g., swales). Transportation of materials and construction civil works had a larger contribution in life cycle inventories and associated environmental impacts in drainage systems with higher demand for materials. The lowest environmental impacts and life cycle costing were from swales, wetland and retention pond. Uncertainty assessment revealed that drainage systems with extensive application of materials and civil work had more negative impacts on human health, ecosystems and resources