Compressed Natural Gas and Liquefied Petroleum Gas Conversions: The National Renewable Energy Laboratory's Experience

https://doi.org/10.21949/14044241996PDFResearch PaperAlternate fuelsCompressed natural gasLiquefied natural gasVehicle fleetsFederal government agenciesProcurement"Closed-loop feedback" conversion kitsCNGEmission monitoringEnergy Policy Act of 1992LPGRenewAlternative fuel vehiclesVehicle conversionMotta, Robert C.Kelly, Kenneth J.Warnock, William W.National Renewable Energy Laboratory (U.S.)NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATIONNTL-ENERGY AND ENVIRONMENT-ENERGY AND ENVIRONMENTNTL-ENERGY AND ENVIRONMENT-Alternative FuelsNTL-ENERGY AND ENVIRONMENT-Environment ImpactsUS Transportation CollectionThe National Renewable Energy Laboratory (NREL) contracted with conversioncompanies in six states to convert approximately 900 light-duty Federal fleetvehicles to operate on compressed natural gas (CNG) or liquefied petroleum gas(LPG). Aftermarket conversions can play an important role in the transition tothe more widespread use of alternative fuel vehicles. In this program, they havebeen successful in helping the Federal government meet the vehicle acquisitionrequirements of EPACT, establishing infrastructure, and increasing thedisplacement of imported oil. The disappointing emissions performance to dateof these closed-loop feedback kits, however, raises the question of theiroverall emissions contribution to the environment. This is especially importantwhen considering converting the latest model year vehicles, which have beencertified to the lower (Tier 1) emissions standards. 19p.establishing infrastructure, and increasing the displacement of imported oil. The disappointing emissions performance to date of these closed-loop feedback kits, however, raises the question of their overall emissions contribution to the environment. This is especially important when considering converting the latest model year vehicles, which have been certified to the lower (Tier 1) emissions standards. 19p.84