CUTR Develops Alternative Fuels for Pinellas Suncoast Transit

Under a contract awarded by the Pinellas County (FL) Metropolitan Planning Organization and funded through the Congestion Mitigation and Air Quality (CMAQ) program, CUTR is completing an alternative fuels implementation plan for the Pinellas Suncoast Transit Authority (PSTA).

The resulting evaluation report examines data on Pinellas County's air quality and identifies the most pressing air quality problems that should be addressed by an alternative fuels implementation plan. The report also examines the state-of-the-art of alternative fuel vehicles in transit and provides an evaluation of the advantages and disadvantages of each fuel type. Recommendations for the alternative fuel (or combination of alternative fuels) most feasible for implementation by PSTA are presented as well.

Fuel types examined in the study were:

• reformulated gasoline (RFG) and reformulated diesel (RFD)
• propane, the main ingredient in liquefied petroleum gas (LPG)
• compressed natural gas (CNG)
• liquefied natural gas (LNG)
• ethanol
• methanol
• biodiese
• electricity (including electric vehicles with solar recharging stations)

A general assessment was performed for the use of these fuels in all types of vehicles in PSTAs fleet--transit buses, passenger vans, and other assorted non-revenue vehicles, with an emphasis on full-size transit buses. This general assessment was followed by a detailed analysis (by bus, by route) to select an alternative fuels implementation plan best suited to current operations at PSTA.

Of the eight different fuel options initially considered (reformulated gasoline and diesel, propane, compressed natural gas, liquefied natural gas, ethanol, methanol, biodiesel and electricity,) two liquid/gas fuels--compressed natural gas and liquefied natural gas--showed the greatest potential for successful conversion and were included in the detailed feasibility analysis. In addition, electricity was also included because of its low cost, availability, and applicability for short-range routes.

The recommended alternative fuels implementation plan uses CNG as the primary fuel, with electricity and diesel as the secondary fuels for routes that either have short ranges and low load factors or require a spare CNG bus from the garage to resume operations during refueling.

A fuel assessment matrix was prepared which evaluated each of the initial eight fuels according to the following criteria:

• air quality impacts
• safety and maintenance issues
• fuel availability
• vehicle availability
• performance
• refueling facilities
• vehicle costs
• fuel costs
• regulatory requirements

Comparative capital, fuel, and maintenance costs were also determined during the evaluation. Based on the detailed feasibility performed by bus and by route for the PSTA fleet, the following recommendations and conclusions were developed:

• The most favorable conversion to alternative fuels is a combination of CNG-electric and diesel (with 97 vehicles converting to CNG, 21 to electric, and five remaining as diesel).
• The greatest benefit in conversion to alternative fuels will be in reduced emissions compared to an all-diesel fleet. Nitrogen oxides will be reduced by approximately one-half, carbon monoxide by two-thirds, and particulate matter would be virtually eliminated.
• This conversion plan require 36 routes to operate exclusively on CNG, eight exclusively on electricity, five on CNG and electricity, one on CNG and diesel, and one on CNG, electricity, and diesel.
• For total PSTA fleet replacement (all in 1994), costs would include $32 million in capital and approximately $2.6 million in annual total operating costs (fuel and maintenance). By comparison, total all-diesel PSTA fleet replacement in 1994 would be approximately $28 million, with estimated annual diesel operating costs of $3.2 million. Refueling facility cost will vary depending on on-site or off-site refueling (at least $300,000 for on-site facility).

Upon completion of the report, PSTA was provided with a phased implementation plan, based on the current replacement schedule for specific diesel bus replacement, that addresses the air quality deficiencies of Pinellas County and maintains the current systemwide service plan.

For further information on this project, contact CUTR Senior Research Associate Michael C. Pietrzyk, P.E.

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