The clean fuel technological advances in public transit vehicles have led the way in helping to introduce clean fuel technological advances in personal automobiles, according to the study, “Transit on the Cutting Edge of Clean Technology,” released by the American Public Transportation Association (APTA). These advances have been implemented through a wide array of federal, state and local policies and are aimed at reducing the nation’s carbon footprint and increase vehicle energy efficiency.

In fact, today’s public transit vehicles are significantly more advanced than automobiles in their ability to run on clean fuels. For instance, buses on the road powered by alternative fuels rose from 2% in 1992 to 36% in 2011. That compares to the percentage of cars capable of being powered by alternative fuels was only 3.2% in 2011.

“Today’s bus is not your father’s bus,” said APTA President/CEO Michael Melaniphy. “Today’s environmentally friendly buses are up to 40 percent more fuel efficient than conventional diesel buses. These energy efficient buses and trains reduce our dependency on foreign oil and give individuals affordable energy efficient choices.”

The industry has accomplished these strong gains by employing key technologies such as electric vehicles, new advances in battery technologies, diesel-electric hybrids, regenerative braking and energy storage, biofuels, natural gas vehicles and hydrogen fuel-cell vehicles.

Electric and hybrid vehicles

These are vehicles that rely, in whole or in part on, electric motors to provide propulsion. Although electric and hybrid automobiles have received a lot of media attention, public transit agencies have been on the forefront of adopting hybrid buses. These are usually diesel-electric hybrids and sometimes gasoline electric hybrids as well as a large number of pure electric vehicles.

According to the Transit Cooperative Research Program, diesel-electric hybrid buses can have 14% to 48% better fuel efficiency than conventional diesel buses while significantly reducing tailpipe emissions. According to APTA’s 2011 Public Transportation Vehicle Database, hybrids accounted for about 17% of the new buses on order by public transit agencies.

“With U.S. greenhouse gases from transportation sources of all modes representing 28 percent of total U.S. emissions, it is important public transportation lead the way with innovative investments,” said Melaniphy. “But it is not just good for the environment, public transit systems operate more efficiently and in turn can reduce operating costs.”

Regenerative braking and energy storage

Public transit agencies have been using regenerative breaking technologies, which capture the energy generated by the trains’ braking systems, for many decades to reduce the energy needs of their rail vehicles. These are systems that capture and store the energy generated by the trains’ braking systems.

Public transit agencies have focused on coupling the regenerative braking with energy storage devices, such as batteries, so that the energy can be stored whenever needed.

In addition, public transit agencies have taken a leading role in employing vehicles that run on energy efficient biofuels, natural gas and hydrogen fuel cells.

Federal Policy Impact

Public transit agency leadership on clean fuels technology has been driven by a wide range of key federal, state and local policies, programs and incentives. These are both new and long existing policy initiatives.

An example of a recent federal policy initiative includes the American Recovery and Reinvestment Act of 2009 which provided significant funding for clean transit purchases and projects around the country particularly under the Transit Investments for Greenhouse Gas and Energy Reduction (TIGGER) program. This program distributed more than $360 million in grants and was renewed in the fiscal 2012 budget deal, but the funding is currently being debated in the 2013 appropriations bills discussions in Congress.

A long standing federal policy which has had great impact is the Clean Air Act Amendments of 1990. This created a Clean Fuel Program that set emission standards for urban buses beginning with model year 1994.

The Fuel Cell Bus program has grants that promote hydrogen fuel-cell buses, and the Department of Energy’s Clean Cities Program where many public transit agencies are members and are eligible for technical assistance and funding opportunities.

Going forward, the new transportation bill (MAP 21) includes a “deployment” program focused on low-and zero emission public transit vehicles, providing grants for acquiring such vehicles and rehabilitating existing facilities to accommodate the use of such vehicles.

State and Local Policy Initiatives

Philadelphia’s SEPTA is piloting a wayside energy storage system funded by a grant for the Pennsylvania Energy Development Authority. New York State Energy Research and Development Authority (NYSERDA) have a Clean Fueled Bus Program that provides funds to state and local public transit agencies for additional cost of a clean-fueled bus and for associated infrastructure project. These awards have amounted to $24.5 million for 520 buses including CNG, electric and diesel-electric hybrid. California and Ohio have both implemented rules aimed at limiting air pollution which led to the purchase of clean diesel, alternative fuels, CNG, hybrids, fuel cells and biodiesels.

“These policies on the federal, state and local level should be maintained and expanded to enable public transit agencies to continue their leadership in transforming their fleets to clean fuel technologies, which leads the way for the rest of the nation,” said Melaniphy.