Last updated February 2026
Overview
SEPTA is striving to transition its diesel-electric hybrid buses to a fully zero-emissions fleet to ensure a clean, sustainable and resilient future. By transitioning to zero-emission buses (ZEBs), combined with reducing car dependency, we aim to significantly improve regional air quality and make a lasting environmental impact.
While we remain committed to this long-term vision, as of 2026 we have adjusted our ZEB transition timeline and shifted our near-term procurement strategy to ensure we provide uninterrupted service and remain fiscally resilient.
Due to capital funding constraints, we have paused purchases of new ZEB pilot technology like battery electric buses. We are currently focusing our resources on maintaining core service while gathering real-world data from our active hydrogen fuel cell electric bus pilot.
Although SEPTA’s ZEB transition plans have shifted, we maintain our commitment to greening our fleet by:
- Expanding our successful hybrid diesel-electric bus program
- Continuing our hydrogen fuel cell electric bus pilot
- Fully electrifying our trackless trolley fleet
- Upgrading our facilities and infrastructure to prepare for ZEB technologies
A National Leader in Green Transit
SEPTA currently operates the largest diesel-electric hybrid bus fleet in the United States.
As of April 2024, 100% of SEPTA’s revenue service buses are high-efficiency hybrids. These buses have integrated electric and diesel systems that conserve energy during starts and braking, using captured energy to recharge the battery and lower fuel use.
Compared to traditional diesel buses, SEPTA’s hybrids:
- Improve fuel efficiency and reduce greenhouse gas emissions by over 30%
- Cut local emissions like particulate matter, carbon monoxide and nitrogen oxides by an estimated 75%
- Reduce maintenance costs
- Reduce noise pollution
SEPTA will continue to replace buses at the end of their useful lives with the latest high-efficiency hybrid diesel-electric buses.
Hydrogen Fuel Cell Electric Bus Pilot
SEPTA is taking a pilot approach to evaluating ZEB technologies to ensure we are making data-informed decisions when it comes to our future bus fleet.
ZEB technologies are advancing rapidly, and different ZEB types vary in performance characteristics and levels of compatibility with SEPTA’s bus schedules. Pilots are an essential step in gathering data and understanding the performance, feasibility and tradeoffs of ZEB options in real-world operations.
SEPTA is currently piloting 10 hydrogen fuel cell electric buses to evaluate how they perform and whether they meet service requirements. These buses are powered by a small battery which is continually recharged by a hydrogen fuel cell (pressurized hydrogen gas).
Our first fuel cell electric buses entered revenue service in Summer 2025. Look for these vehicles to start on Route 16 and Route 23. SEPTA plans to continue to pilot these buses on diverse routes and operating conditions to collect and analyze data to inform decisions around future fleet makeup.
Fully Electric Trackless Trolleys
SEPTA’s trackless trolleys (trolleybuses) are rubber-tired electric vehicles with two poles on top that connect with overhead wires for the entire length of each route. However, they can travel off-wire for a limited time using backup power (currently diesel).
SEPTA is transitioning to a new generation of fully electric trackless trolleys, which will replace the backup diesel engines with batteries, making them completely zero emission.
Facility and Infrastructure Upgrades
SEPTA is continuing essential facility upgrades at our maintenance depots. These projects ensure our buildings are up to code and ready to accommodate the fueling, storage, and maintenance requirements of our modernized fleet.
Long Term Vision
SEPTA’s 2022 ZEB Playbook provides strategic direction for transitioning our fleet to all ZEBs. It includes where to prioritize initial investments and next steps for piloting concepts and beginning the implementation process.
While we have paused purchases of new ZEB technology at this time, we will continue to:
- Learn from peer agencies who are already piloting or transitioning their fleets
- Stay informed about the latest technological advancements and vehicle performance
- Prepare our facilities and infrastructure for a ZEB future
- Re-evaluate our funding situation and identify opportunities for strategic ZEB investments
- Strive towards net zero greenhouse gas emissions by 2050
Questions or Comments?
Email us at [email protected]
Building a Lifestyle Transit Network
As part of our 12-year capital investment program, we’re making stations accessible, acquiring new vehicles, investing in communications and upgrading services for our buses, Metro and rail to deliver on our vision of easy to use, frequent and integrated transit.