Emerging Issues Forum

 
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Name: Michael Coates

Comments: The Diesel Technology Forum, the nation’s leading resource and educator on the importance and unique value of diesel engines, fuels, equipment and emissions control technology, would like to add these comments to the PUC white paper, "The Case for Diesel Cars in California" Overall, we welcome the intent and content of the white paper, which supports modern clean diesel technology as a greenhouse-gas reduction tool. It's characterization of clean diesel as an "alternative path" to longer-term electrification is worthy of serious consideration. Most of all, we support the paper’s call for a multi-agency (PUC, CARB, CEC) workshop to understand how diesel and biodiesel vehicles can serve as a complementary avenue to reduce GHG emissions in the transport sector (page 12). In fact, the state's Energy Commission has previously recognized some of these tenants in the 2005 Integrated Energy Policy Report (http://www.energy.ca.gov/2005publications/CEC-100-2005-007/CEC-100-2005-007-CMF.PDF). The report notes that a shift from gasoline to diesel in the state's light-duty fleet could significantly reduce the state's petroleum use. We would like to submit the following corrections and comments on the white paper: Overall – The paper uses the terms "emissions" and "pollution" or "polluting" interchangeably, while referring at various points to criteria pollutants and greenhouse gas emissions. It would be clearer if the two terms were used consistently and correctly. For instance, on page 2 the statement that "Diesel cars are less polluting than gasoline-fueled vehicles" is not true if it refers to criteria pollutants (specifically for NOx as is noted later in the white paper), so it must be assumed that it refers to greenhouse gas emissions, though this is not specified in the text. It should also be noted on page 2 that under the pending LEV III regulations, all new vehicles sold in California, including diesel models, will have to meet SULEV tailpipe criteria emissions levels. California’s current LEV II requires that all new vehicles sold in the state meet ULEV. On page 3 the presentation of B20 GHG emissions numbers is misleading since no light-duty automakers recommend B20 in their clean diesel cars. Currently B5 is the highest blend recommended because of potentially negative effects on emissions equipment from FAME biodiesel. Some automakers allow B20 in diesel heavy light-duty pickups if it meets certain quality specifications. It should also be noted that California Air Resources Board (CARB) recent testing of biodiesel and renewable diesel has found NOx increases with higher blends of biodiesel, though not with renewable diesel. (http://www.arb.ca.gov/fuels/multimedia/BiodieselDurabilityPresentation2010_08_11.pdf). On page 3 it should be noted that PM emissions are not an issue with modern clean diesel vehicles because they all employ diesel particulate filters (DPFs). On page 5 the comparison between vehicles with gasoline and diesel engines is not clearly presented. The vehicles cited are European-spec vehicles not offered in those versions in the U.S. Some similar models might be offered, but the fuel economy numbers presented should be clarified as applicable to European models only and using Europe's fuel economy measurement program, not NHTSA's in the U.S. Since clean diesel vehicles are available for sale in California, a chart could be constructed showing diesel and gas versions of the VW Jetta, Golf or Touareg, or several Audi, BMW or Mercedes models that are on sale here with both powertrains. In addition, it should be noted that engine size is only one measure of comparative automotive features. Since the diesel engine produces more torque than a similar-size gasoline engine, true comparisons of performance would show a four-cylinder diesel engine compared to a six-cylinder gas engine, resulting in an even more significant fuel economy differential. On page 6 a pricing comparison for hybrids and clean diesels versus comparable gasoline versions of vehicles could have been made that showed higher price premiums for hybrids than clean diesel models offered in the U.S. Price premium information is sometimes difficult to delineate, though, as sometimes the models offered contain different equipment, which may skew the prices while not reflecting the cost of the different powertrain. A more significant addition might be cost of ownership data from a recent Carnegie Mellon University study that shows lower lifecycle costs of owning diesel vehicles compared to gasoline ones. (http://www.cmu.edu/news/archive/2011/January/jan27_dieselvehicles.shtml). On page 7, the assertion that because auto companies are producing low-emission diesel engines in Europe, they could "easily supply" these cars to the California and U.S. markets is a gross oversimplification of the complexity of differing automotive standards for not only emissions, but other vehicles standards relating to safety and equipment. It also ignores other competing cost and market considerations that auto companies face. The Biodiesel section on pages 8 and 9 needs to be updated with current information from CARB on bio-based diesel fuels. Use of FAME (fatty acid methyl ester) biodiesel in blends greater than 5 percent can have negative impacts (i.e. nozzle coking, cetane variations, etc.) on modern diesel vehicles’ ultra-sensitive emissions control equipment. There is no distinction in this section between Generation 1 FAME biodiesel and Generation 2 non-ester renewable diesel. Most OEMs would allow higher concentrations of renewable diesel if it were available due to the higher quality and better emissions performance. We would encourage the author and CPUC staff to become more familiar with bio-based diesel fuels and their life-cycle GHG emissions characteristics by reviewing CARB’s development of the Low Carbon Fuel Standard (see: http://www.arb.ca.gov/fuels/lcfs/lcfs.htm). [We will submit further comments]
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