Constantine Samaras

Valuation of plug-in vehicle life-cycle air emissions and oil displacement benefits.

We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO2 emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent.

Life Cycle Assessment and Grid Electricity: What Do We Know and What Can We Know?

The generation and distribution of electricity comprises nearly 40% of U.S. CO(2), emissions, as well as large shares of SO(2), NO(x), small particulates, and other toxins. Thus, correctly accounting for these electricity-related environmental releases is of great importance in life cycle assessment of products and processes. Unfortunately, there is no agreed-upon protocol for accounting for the environmental emissions associated with electricity, as well as significant uncertainty in the estimates. Here, we explore the limits of current knowledge about grid electricity in LCA and carbon footprinting for the U.S. electrical grid, and show that differences in standards, protocols, and reporting organizations can lead to important differences in estimates of CO(2) SO(2), and NO(x) emissions factors. We find a considerable divergence in published values for grid emissions factor in the U.S. We discuss the implications of this divergence and list recommendations for a standardized approach to accounting for air pollution emissions in life cycle assessment and policy analyses in a world with incomplete and uncertain information.

Estimation of regional air-quality damages from Marcellus Shale natural gas extraction in Pennsylvania

This letter provides a first-order estimate of conventional air pollutant emissions, and the monetary value of the associated environmental and health damages, from the extraction of unconventional shale gas in Pennsylvania. Region-wide estimated damages ranged from

Long-term electric system investments to support Plug-in Hybrid Electric Vehicles

7.2 to

Estimating the Consumptive Use Costs of Shale Natural Gas Extraction on Pennsylvania Roadways

32 million dollars for 2011. The emissions from Pennsylvania shale gas extraction represented only a few per cent of total statewide emissions, and the resulting statewide damages were less than those estimated for each of the states largest coal-based power plants. On the other hand, in counties where activities are concentrated, NOx emissions from all shale gas activities were 20–40 times higher than allowable for a single minor source, despite the fact that individual new gas industry facilities generally fall below the major source threshold for NOx. Most emissions are related to ongoing activities, i.e., gas production and compression, which can be expected to persist beyond initial development and which are largely unrelated to the unconventional nature of the resource. Regulatory agencies and the shale gas industry, in developing regulations and best practices, should consider air emissions from these long-term activities, especially if development occurs in more populated areas of the state where per-ton emissions damages are significantly higher.

Life cycle greenhouse gas emissions from U.S. liquefied natural gas exports: implications for end uses.

Plug-in hybrid electric vehicles (PHEV) represent a promising pathway to reduce greenhouse gas emissions associated with the U.S. transportation sector. A large-scale shift from gasoline-powered automobiles to PHEVs would inextricably link the U.S. transportation system with its electric system. We build on [4] to perform a regional emissions analysis of a PHEV use pattern where PHEVs are charged at night and discharged during the day. We find that in some coal-intensive regions like the Midwest, charging PHEVs by burning coal may produce more emissions than burning gasoline. Overnight charging of PHEVs will deteriorate the system load factor by increasing off-peak demand. This may have deleterious effects on system infrastructure. We perform some simple simulations looking at the effect of off-peak PHEV charging on the performance of oil-cooled substation transformers.

Uncertainty and variability in accounting for grid electricity in life cycle assessment

AbstractThe development of natural gas resources in the Marcellus Shale formation has progressed rapidly in the last several years, particularly in the Commonwealth of Pennsylvania. These activities require many heavy truck trips for equipment and materials, which can damage state and local roads that were not designed for high volumes of heavy truck traffic. For state transportation agencies, one measure of costs of shale gas development is the potential degradation of roadways resulting from shale gas development. This technical note, provides a first-order an estimate of roadway consumptive use costs of additional heavy truck traffic on Pennsylvania state-maintained roadways from Marcellus Shale natural gas development in 201, estimated at 1 about

Cost and benefit estimates of partially-automated vehicle collision avoidance technologies

13,000–

Beyond Global Warming Potential: A Comparative Application of Climate Impact Metrics for the Life Cycle Assessment of Coal and Natural Gas Based Electricity

23,000 per well for all state roadway types, or

Transitions in energy systems

5,000–