[Due to the increasing size of the archives, each topic page now contains only the prior 365 days of content. Access to older stories is now solely through the Monthly Archive pages or the site search function.]
CMU county-level study shows plug-ins have larger or smaller lifecycle GHG than gasoline ICE depending on regional factors
April 09, 2016
A US-wide county-level study comparing lifecycle greenhouse gas (GHG) emissions from several light-duty passenger gasoline and plug-in electric vehicles (PEVs) has found that PEVs can have larger or smaller carbon footprints than gasoline vehicles depending on regional factors and the specific vehicle models being compared.
The team from Carnegie Mellon University led by Dr. Jeremy Michalek accounted for regional differences in emissions due to marginal grid mix; ambient temperature; patterns of vehicle miles traveled (VMT); and driving conditions (city versus highway). Their open-access paper is published in the journal Environmental Research Letters.
Argonne LCA study finds many alternative fuels consume more water than petroleum and natural gas fuels
March 09, 2016
Researchers at Argonne National Laboratory have analyzed the water consumption for transportation fuels in the United States using an extended lifecycle system boundary that includes the water embedded in intermediate processing steps.
In a paper published in the RSC journal Energy & Environmental Science, they compared the water consumed per unit energy and per km traveled in light-duty vehicles. They found that many alternative fuels consume larger quantities of water on a per km basis than traditional petroleum and natural gas pathways. The authors concluded that it will be important to consider the implications of transportation and energy policy changes on water resources in the future.
Rice study finds using natural gas for electricity and heating, not transportation, more effective in reducing GHGs
Rice University researchers have determined a more effective way to use natural gas to reduce climate-warming emissions would be in the replacement of existing coal-fired power plants and fuel-oil furnaces rather than burning it in cars and buses.
The Rice study by environmental engineer Daniel Cohan and alumnus Shayak Sengupta compared the net greenhouse gas-emission savings that could be realized by replacing other fuels in vehicles, furnaces and power plants. They found that gas-fired power plants achieved the greatest reduction—more than 50%—in net emissions when replacing old coal-fired power plants. The use of compressed natural gas in vehicles yielded the least benefit, essentially matching the emissions of modern gasoline or diesel engines.
Singapore considers Model S EV a high carbon emission vehicle based on fuel consumption and upstream power generation
Channel NewsAsia recently reported on the case of a Tesla Model S owner in Singapore who, rather than receiving the Carbon Emissions-based Vehicle Scheme (CEVS) rebate he expected of S$15,000 (US$10,841) was hit with a CEVS surcharge of S$15,000 for having high carbon emissions.
Under Singapore’s revised Carbon Emissions-Based Vehicle Scheme (CEVS), all new cars and imported used cars registered from 1 July 2015 with low carbon emissions of less than or equal to 135g CO2/km qualify for rebates of between S$5,000 (US$3,614) and S$30,000 (US$21,681), which are offset against the vehicle’s Additional Registration Fee (ARF). Cars with high carbon emissions equal to or more than 186g CO2/km incur a registration surcharge of between S$5,000 and S$30,000.
CMU study finds that coal retirement is needed for EVs to reduce air pollution
February 12, 2016
Electric vehicles charged in coal-heavy regions can create more human health and environmental damages from life cycle air emissions than gasoline vehicles, according to a new consequential life cycle analysis by researchers from Carnegie Mellon University. However, the anticipated—albeit now possibly delayed, per the recent Supreme Court decision—retirement of coal-fired power plants will make electric vehicles more competitive on an air emissions basis, the researchers found.
Among the findings of the study, published as an open-access paper in the journal Environmental Research Letters, was that battery electric vehicles with large battery capacity can produce two to three times as much air emissions damage as gasoline hybrid electric vehicles, depending on charge timing.
FuelCell Energy pathway for hydrogen from digester gas has negative carbon intensity for CA LCFS
December 23, 2015
Connecticut-based FuelCell Energy (FCE) has applied for a prospective pathway for California’s Low Carbon Fuel Standard (LCFS) for the production of hydrogen fuel produced from biogas derived from the mesophilic anaerobic digestion of wastewater sludge at a publicly owned treatment works (POTW).
The biogas is cleaned, then internally reformed in an integrated hydrogen energy system (Tri-Gen DFC) that produces hydrogen fuel for transportation; electric power for plant operations and export; as well as thermal energy for plant use. Once the internal energy demands of the pathway have been met, any energy not utilized for process is considered to be surplus to the system boundary and is credited to the FCE pathway.
Mercedes-Benz publishes lifecycle analysis of its first PHEV SUV: GLE 500 e
December 22, 2015
The GLE 500 e 4MATIC burns 3.7–3.3 liters of fuel for every 100 km (63.5 to 71.2 mpge), equating to CO2 emissions of 84–78 g/km; electric power consumption is 16.7 kWh per 100 km. All-electric range is up to 30 km (18.6 miles), and all-electric top speed is 130 km/h (81 mph)—corresponding to the recommended speed on German autobahns.
EPA: jatropha-based biofuels could qualify as biomass-based diesel or advanced biodiesel under RFS
October 19, 2015
Based on its analysis of the production and transport components of the lifecycle greenhouse gas emissions of biofuel made from jatropha oil, the US EPA anticipates that biofuels produced from jatropha oil could qualify as biomass-based diesel or advanced biofuel under the Renewable Fuel Standard program if typical fuel production process technologies or process technologies with the same or lower GHG emissions are used. EPA has published its analysis in the Federal Register and is inviting comment.
Background. The RFS regulations lists three critical components of an approved fuel pathway: (1) Fuel type; (2) feedstock; and (3) production process. EPA uses lifecycle analysis to assess the overall greenhouse gas (GHG) impacts of a fuel throughout each stage of its production and use.
Argonne analysis shows greenhouse gas emissions similar for shale, conventional oil
October 16, 2015
Shale oil production generates greenhouse gas emissions at levels similar to conventional crude oil production, according to a pair of new studies released by the US Department of Energy’s Argonne National Laboratory.
The research, conducted by Argonne researchers in collaboration with Stanford University and the University of California, Davis, analyzed the Eagle Ford shale formation in Texas and the Bakken play mainly in North Dakota. Eagle Ford and Bakken are the second and third largest oil-producing shale formation regions in the United States, during the last three years. In 2014, Bakken and Eagle Ford together accounted for 54% of oil production and 19% of gas production among the top seven production regions. These are shale formations with low permeability and must be hydraulically fractured to produce oil and gas.
Argonne study finds lightweight material substitution increases vehicle-cycle GHGs, but results in total life-cycle benefit
October 12, 2015
A team at Argonne National Laboratory has taken a closer look at vehicle-cycle (all processes related to vehicle manufacturing) and vehicle total life-cycle (vehicle-cycle plus fuel cycle—i.e., the use phase) impacts of substituting lightweight materials into vehicles.
In a study published in the ACS journal Environmental Science & Technology, they reported that while material substitution can reduce vehicle weight, it often increases vehicle-cycle greenhouse gas emissions GHGs—for example, replacing steel with wrought aluminum, carbon fiber reinforced plastic (CRFP), or magnesium increases the vehicle-cycle GHGs. However, lifetime fuel economy benefits often outweigh the vehicle-cycle, resulting in a net total life-cycle GHG benefit, they found. This is the case for steel replaced by wrought aluminum in all assumed cases, and for CFRP and magnesium except for high substitution ratio and low fuel reduction value.
Honda launches new “Green Path” initiatives for manufacturing and operations; new $210M paint line at Marysville with new 4C2B process
September 25, 2015
Honda has announced several initiatives under its new “Green Path” approach to reducing the total life-cycle environmental impact of its products and operations in North America. Among these is a $210-million investment in a new, more environmentally responsible auto-body painting facility and innovative paint process at its Marysville, Ohio auto plant (MAP), the largest of Honda’s eight auto plants in North America. MAP produces the Honda Accord Sedan and Coupe along with the Acura TLX and ILX for customers in more than 100 countries.
Honda has established a voluntary goal to reduce its total GHG emissions—including customer use-phase—by 50% by the year 2050, compared to 2000 levels; this works out to a reduction of 90% per unit sales—a difficult task, noted Ryan Harty, a former Honda R&D engineer who now manages Honda’s new Environmental Business Development Office.
EPRI-NRDC report finds widespread vehicle electrification and a cleaner grid could lead to substantial cuts in GHG by 2050
September 21, 2015
Widespread adoption of electric transportation, including electrification in the off-road sector, could lead to substantial reductions in greenhouse gas (GHG) emissions and could modestly improve air quality, according to a new analysis released by the Electric Power Research Institute (EPRI) and the Natural Resources Defense Council (NRDC).
The report, “Environmental Assessment of a Full Electric Transportation Portfolio”, is based on a projection that by 2050 electricity replaces traditional fuels for approximately half of light- and medium-duty transportation and a significant portion of non-road equipment. This study builds on the 2007 Environmental Assessment of Plug-in Hybrid Electric Vehicles by EPRI and NRDC (earlier post), which showed that plug-in hybrid electric vehicles could contribute to reductions in national greenhouse gas emissions, while also leading to improved air quality. As with the earlier assessment, this study consists of two separate, but related, analyses: greenhouse gas emissions from 2015-2050, and air quality impacts in 2030.
CMU analysis finds BEVs powered with natural gas-based electricity have about 40% of the lifecycle GHGs of a conventional gasoline vehicle
August 21, 2015
According to a new lifecycle analysis by a team at Carnegie Mellon University, a battery electric vehicle (BEV) powered with natural gas-based electricity achieves around an average 40% lifecycle greenhouse gas (GHG) emissions reduction when compared to a conventional gasoline vehicle. Plug-in hybrids (PHEVs), either with a 30- or 60-km range, when powered by natural gas electricity, have the second lowest average emissions. Both BEVs and PHEVs provide large (more than 20%) emissions reductions compared to conventional gasoline, but none of them is a dominant strategy when compared to gasoline hybrid electric vehicles (HEVs), the team found.
Gaseous hydrogen fuel cell electric vehicles (FCEVs) and compressed natural gas (CNG) vehicles have comparable life cycle emissions with conventional gasoline, offering limited reductions with 100-year global warming potential (GWP) yet leading to increases with 20-year GWP. Other liquid fuel pathways using natural gas—methanol, ethanol, and Fischer–Tropsch liquids—have larger GHG emissions than conventional gasoline even when carbon capture and storage technologies are available. The study is published in the ACS journal Energy & Fuels.
Study finds EV use-phase fuel savings exceed marginal increase in energy demand for WBG semiconductor manufacturing by 2 orders of magnitude
August 14, 2015
Power electronics semiconductors, which manage voltage and current, are a key technology for enabling improvements in “fuel economy” in electric vehicles. While conventional silicon-based semiconductor technology currently owns the plug-in vehicle power electronics market, emerging wide band gap (WBG) semiconductors offer significantly greater energy efficiency potential than silicon.
A team from Oak Ridge National Laboratory, Argonne National Laboratory, Northwestern University and the US Department of Energy (DOE) has now estimated the potential energy benefits in electric vehicles for two leading WBG semiconductor architectures—silicon carbide (SiC) and gallium nitride (GaN)—and compared those with conventional silicon. Their paper is published in the ACS journal Environmental Science & Technology.
EPA honors winners of the 20th Annual Presidential Green Chemistry Challenge; advanced biofuels
July 14, 2015
The US Environmental Protection Agency (EPA) honored the six 2015 Presidential Green Chemistry Challenge Award winners at a ceremony in Washington, DC. EPA’s Office of Chemical Safety and Pollution Prevention sponsors the Presidential Green Chemistry Challenge Awards in partnership with the American Chemical Society Green Chemistry Institute and other members of the chemical community including industry, trade associations, academic institutions, and other government agencies.
For 2015, EPA announced a new award category for a green chemistry technology that has a “Specific Environmental Benefit: Climate Change.” The 2015 winners are Algenol; Lanzatech; Renmatix; Professor Eugene Y.-X. Chen of Colorado State University; Soltex; and Hybrid Coating Technologies.
U Calgary study finds oil shale most energy intensive upgraded fuel followed by in-situ-produced bitumen from oil sands
July 10, 2015
A team at the University of Calgary (Canada) has compared the energy intensities and lifecycle GHG emissions of unconventional oils (oil sands and oil shale) alongside shale gas, coal, lignite, wood and conventional oil and gas. In a paper published in the ACS journal Environmental Science & Technology, they report that lignite is the most GHG intensive primary fuel followed by oil shale. Oil shale is the most energy intensive fuel among upgraded primary fossil fuel options followed by in-situ-produced bitumen from oil sands.
Based on future world energy demand projections, they estimate that if growth of unconventional heavy oil production continues unabated, the incremental GHG emissions that results from replacing conventional oil with heavy oil would amount to 4–21 Gt-CO2eq over four decades (2010 by 2050). Taking this further, they estimated that the warming associated with the use of heavy oil amounts to this level of emissions could lead to about 0.002−0.009 °C increase in earth surface temperature, based on mid-21st century carbon-climate response model estimates.
Researchers find Nissan LEAF creates less CO2 than Toyota Prius hybrid in west US and Texas, but more in N. Midwest
July 01, 2015
Regionally specific lifecycle CO2 emissions per mile traveled for plug-in hybrid electric vehicles (PHEVs) and battery electric vehicles (BEVs) in the US can vary widely based on grid emission factors (i.e., the “carbon footprint” of electricity production and use), according to a new study by researchers at Carnegie Mellon University. Under some conditions, the battery electric Nissan LEAF can produce higher emissions than a Toyota Prius hybrid. The paper is published in the ACS journal Environmental Science & Technology.
The team characterized the vehicle emissions across the United States under alternative assumptions for regional electricity emission factors, regional boundaries, and charging schemes. Among the findings were that:
New lifecycle analysis of WTW GHG emissions of diesel and gasoline refined in US from Canadian oil sands crude
June 26, 2015
In a new, comprehensive study, a team from Argonne National Laboratory, Stanford University and UC Davis ITS has estimated the well-to-wheels (WTW) GHG emissions of US production of gasoline and diesel sourced from Canadian oil sands. The analysis uses an expanded system boundary including land disturbance-induced GHG emissions and also incorporates operating data that represent the average practices and technological advances of the oil sands industry since 2008. The study is published in the ACS journal Environmental Science & Technology.
The researchers examined 27 oil sands projects, representing four major oil sands production pathways, including bitumen and synthetic crude oil (SCO) from both surface mining and in situ projects. Overall, they found that pathway-average GHG emissions from oil sands extraction, separation, and upgrading ranged from ∼6.1 to ∼27.3 g CO2 equivalents per megajoule (in lower heating value, CO2e/MJ). This range can be compared to ∼4.4 g CO2e/MJ for US conventional crude oil recovery.
Up close and personal with Volkswagen’s e-Golf carbon offset project: Garcia River Forest
June 08, 2015
|TCF, the manager of the Garcia River Forest Project, would like to enable its increasing number of redwood trees to reach the 1,000-year-old status of some of their neighbors, like this one. Click to enlarge.|
In 2014, Volkswagen of America announced that starting with the launch of the zero-tailpipe emissions battery-electric 2015 e-Golf (earlier post), it would invest in projects to offset the carbon emissions created from the e-Golf on a full lifecycle basis: production, distribution and up to approximately 36,000 miles (57,936 km) of driving.
Last week, Volkswagen provided a close-up look at one of the projects in which it is investing: the Garcia River Conservation-Based Forest Management Project, located in Mendocino County, California. This project, to which Volkswagen contributes along with companies such as UPS, repairs and preserves a ~24,000-acre native redwood forest, increasing carbon sequestration and storage, while also helping to restore the natural wildlife habitat. Emission reductions produced by the project are verified by an approved third party and registered with the Climate Action Reserve (Project ID CAR102).
CMU study compares lifecycle GHGs of natural gas pathways for MHDVs; MD BEVs can deliver large reductions, but diesel hard to beat for Class 8
May 27, 2015
A study by Carnegie Mellon University researchers comparing life cycle greenhouse gas (GHG) emissions from different natural gas pathways for medium and heavy-duty vehicles (MHDVs) found that the GHG reduction potentials of the pathways vary sharply between non-Class 8 MHDVs (e.g., pick-up trucks, parcel delivery trucks, and box trucks), Class 8 transit buses, and Class 8 MHDVs (e.g., refuse trucks and tractor-trailers).
Battery-electric (BEVs), LPG, and CNG pathways could reduce life cycle GHG emissions for non-Class 8 MHDVs compared to the baseline petroleum fuels. Similarly, BEVs achieve emission reductions for transit buses. On the other hand, none of natural gas pathways, CNG, LNG, and F-T liquids, achieve any emission reductions per unit of freight-distance moved for Class 8 trucks compared to conventional diesel. The study is published in the ACS journal Environmental Science & Technology.
Lifecycle study finds fuel switching from diesel to natural gas could produce net climate damage absent reductions in CH4 emissions and improved vehicle efficiency
May 20, 2015
A study by a team from the Environmental Defense Fund, in collaboration with a colleague from the Lenfest Center for Sustainable Energy at Columbia University has found that while switching a heavy-duty truck fleet from diesel to natural gas has the potential to produce climate benefits, realizing that potential would require a combination of significant reductions well-to-wheels methane emissions (i.e., addressing leakage) and efficiency improvements in the natural gas vehicles themselves. Otherwise, fuel switching can produce net climate damages (more radiative forcing) for decades.
The results, published in an open access paper in the ACS journal Environmental Science & Technology, suggest that policymakers wishing to address climate change should use caution before promoting fuel switching to natural gas, the authors concluded.