Even beyond the big, well-publicized orders in New York, Toronto and Seattle, the growth of hybrid buses in the past year has been on a steep, upward slope on a graph. Indeed, several industry sources now estimate that between 1,000 and 2,000 hybrids are already operating in revenue service or will soon be deployed. In addition, another 1,000 or more hybrids will likely be procured during the next two years, and several other thousands are said to be considered in orders during the next five years.

If this interest materializes — and as all bus manufacturers know, “interest” hardly constitutes “orders” — hybrid propulsion could become the fastest growing alternative technology to diesel-mechanical drivetrains in the transit industry. In the United States more than 40 different cities are operating or planning to implement hybrid bus technology, according to a recent report released by the Northeast Advanced Vehicle Consortium (NAVC).

That interest could get an additional boost thanks to the recently enacted federal transit reauthorization legislation. In language in the conference report of the FY 2006 Transportation, Treasury and Independent Agencies Appropriations Act, Congress directed the FTA to implement a “hybrid bus initiative,” because “… hybrid buses offer reduced fuel consumption while utilizing existing infrastructure, a significant benefit particularly at a time when fuel conservation is paramount. Also, reduced maintenance for hybrid buses equates to significant life-cycle cost benefits.”

The FTA has proposed to fulfill this mandate by launching a program similar to the Alternative Fuels Initiative in the 1990s. The hybrid program would buy down 100 percent of the incremental cost of hybrids over the cost of conventional bus drivetrains, which would virtually eliminate the remaining economic argument against the technology, says Walt Kulyk, the director of the Office of Mobility Innovation in the FTA.

The “Case for Hybrids” Developed

Last year, WestStart-CALSTART launched another FTA-funded project, known as the Hybrid Truck Users Forum (HTUF) Bus Working Group. Building on the success of the HTUF in getting truck fleets to create enough common interest to incentivize manufacturers to offer hybrid technology in medium and heavy-duty truck markets, the Bus Working Group first met at last year’s APTA Bus Conference in Columbus, Ohio, for a similar purpose in the transit bus market. In launching the project, both the FTA and WestStart-CALSTART believe that if the much smaller transit bus market can find common linkages of components or other technologies with much larger truck markets, it can help lower the costs and thus accelerate adoption of hybrid systems in all heavy-duty vehicle markets.

While the gathering at this first meeting discovered that the transit market was much farther ahead than the truck markets in adopting hybrids and therefore the issues were different, representatives of 16 transit bus fleets did agree to several important activities that would help speed commercialization of hybrids in buses. The first of these was to develop a cohesive “case for hybrids” document that can help more fleets make decisions to purchase hybrids, thereby increasing market volumes for manufacturers of these systems and related components. In doing so, costs will come down and thereby catalyze a virtuous “demand-cost cycle” that will help deploy the technology throughout not only the transit bus market but also related markets that share components and systems.

Although a plethora of studies and reports have documented various benefits of hybrids, there has been no single place where all issues are included in a single document specifically tailored to transit buses. Released in December 2005 and titled “The Case for Hybrids In Transit Buses,” this document was intended to fill this gap by gathering and analyzing the available reports and data in a cohesive and compelling argument for hybrids as a propulsion technology choice. By doing so, this “case for” will help policy-makers, technical staff of transit agencies and other stakeholders make a decision to make the additional initial capital request required in a hybrid procurement.