Reports and Studies

Reports and Studies: Alternative Fuel Vehicle Applications

Industrial Truck Emission Data Compared by Fuel is available from the Propane Education Research Council. 9 pages, in Word format. Discusses key emissions studies from the 1990s to present. 

Case Study of CNG Buses in Washington DC   The Department of Energy's National Renewable Energy Laboratory has published a fact sheet titled "Evaluating the Emission Reduction Benefits of WMATA Natural Gas Buses". The fact sheet details emission testing of compressed natural gas (CNG) and diesel transit buses operated by the Washington Metropolitan Area Transit Authority (WMATA). Compared with their conventional diesel counterparts, the CNG buses produced 53% lower oxides of nitrogen, 85% lower total particulate matter, and 89% lower carbon monoxide emissions. 

Bus Futures: New Technologies for Cleaner Cities This evaluation from INFORM, Inc. looks at the latest innovations in fuels and engine technology in the US bus industry. It offers a side-by-side comparison of the commercial availability, performance, emissions, safety, and costs of conventional diesel versus conventional natural gas buses. The status and emissions performance of newer technologies, such as hybrid electric-diesel, hybrid electric-natural gas, and fuel cell buses, are also discussed. James S. Cannon and Chyi Sun (2000, 76 pp., $30) ISBN 918790-74-8   A printed copy of the report is available from INFORM or you can download the report from their website.

No Breathing in the Aisles: Diesel Exhaust Inside School Buses The much-talked-about report was issued by the Natural Resources Defense Council. See the full report, in both PDF and HTML format on the NRDC Website.

NGVC Publishes Second Clean Bus Report The Natural Gas Vehicle Coalition this week published the second quarterly issue of the Clean Bus Report. The newsletter is geared to elected officials and board members of transit agencies and is designed to provide transit officials and decision-makers with accurate information about alternative fuel technology. The April issue features news on the latest on the legislative front, updates on recent transit bus purchases and the next step on the path to hydrogen, among other things. You can access the Clean Bus Report on the NGVC website or if you would like to receive a copy of the Clean Bus Report directly, contact Colleen MacMillan at (202) 824-7365 or cmacmillan@ngvc.org.

Study Compares Alternative Fuel Forklift Emissions The Propane Education and Research Council (PERC) recently released a review of forklift emission studies, titled "Industrial Truck Emission Data Compared by Fuel", that compares emissions data from propane-powered forklifts to findings from forklifts powered by compressed natural gas (CNG) and standard gasoline. The review finds that propane forklifts fitted with approved closed loop controls and exhaust catalysts result in very low emissions that meet and exceed California Air Resource Board Large Spark Ignition standards. Additionally, the review finds that propane demonstrates the highest energy efficiencies when compared to other fuel production life cycles. The review examines research findings from seven forklift emissions studies performed between 1990 and 2002, including two studies that used life cycle analyses emissions models to assess the emissions impact of upstream production of a given fuel.

United Parcel Service Natural Gas Vehicles A study by the National Renewable Energy Laboratories (NREL) of delivery trucks operated by United Parcel Service (UPS) shows that the natural gas trucks produced 75 percent lower carbon monoxide emissions and half of the nitrogen oxide emissions of similar diesel vehicles. The report can be downloaded or for more information contact Kevin Walkowicz at (303) 275-4492 or kevin_walkowicz@nrel.gov.

New Study Confirms Viability of Natural Gas Garbage Trucks  In this new report, INFORM, Inc. explores the significant environmental and public health impacts of diesel-fueled garbage trucks and documents a successful shift from diesel fuel to natural gas in the garbage truck sector.

CARB Report Confirms Emissions Advantages of CNG Transit Buses  A recently released  California Air Resources Board (CARB) report finds natural gas transit buses equipped with oxidation catalysts are far cleaner than diesel buses equipped with emissions after-treatment devices and run on ultra-low sulfur fuel. The report, “Report of Partial Results: Emissions From Two Oxidation Catalyst-Equipped CNG Buses,” presents preliminary results of the second phase of a study initiated by CARB in June 2001. The first phase of the study, completed in April 2002, compared emissions of an in-service natural gas bus without an oxidation catalyst to those of a diesel bus that had been upgraded with a state-of-the-art catalyzed muffler and a continuously regenerating diesel particulate filter.  The methodology and the results of the first phase of the study caused much disagreement between diesel and natural gas industry advocates. Diesel industry advocates claimed the study confirmed environmental advantages of diesel over natural gas, while natural gas industry advocates claimed the study's methodology provided a false "apples-to-oranges" comparison.  The study's second phase appears to provide a more accurate comparison. The CARB study confirms that, when equipped with advanced emissions control technology, both the CNG and diesel buses produced far fewer toxic emissions than their conventional counterparts. However, CARB data also show that the diesel bus equipped with a particulate trap filter actually produced more nitrogen oxides (NOx) than its conventional counterpart while the advanced natural gas bus produced less NOx than a conventional natural gas bus and less than half that of a comparable diesel bus.  The report will be available on CARB’s web site in early September 2002.