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SEPTA Hydrogen Bus Project

Pilot/Test Project

The Southeastern Pennsylvania Transportation Authority’s (SEPTA) Hydrogen Bus Project is a pilot project that implements the use of 10 hydrogen fuel cell powered buses beginning in the fall of 2024. From April 2024 through to the fall of 2024, SEPTA states they will be “piloting” the hydrogen buses but it is unclear exactly what that means. SEPTA states that from the fall of 2024 on, the buses are expected to be put into operation in the city for a pilot or test period. During this same period, 10 New Flyer fully electric buses will also be tested. These buses will be operated on various routes around the city of Philadelphia for the next year. The testing period will culminate in approximately the fall of 2025, at which time it is expected that SEPTA will decide which technology to proceed with in the future to power its bus fleet (either hydrogen fuel cell or fully electric or both).

This is part of SEPTA’s larger strategic plan to have a zero-emissions bus fleet in place by 2045. The current bus fleet, powered by diesel fuel, will be phased out or converted to alternative power sources beginning in 2025. The 10 hydrogen fuel cell powered buses in the pilot program will operate out of the Midvale bus depot located at 2401 Roberts Ave. in Philadelphia. The hydrogen will be produced using electrolyzers and shipped approximately 800 miles via electric trucks from Tennessee in containers as a crypto-temp liquid. At the Midvale bus depot, the liquid hydrogen will be warmed to a compressed gas that feeds the fuel cells to power the bus. While in use, the hydrogen gas will be carried in canisters on the roofs of the buses.

Expanded Plans at Build Out

The pilot program is just the start of SEPTA’s hydrogen bus plans. A 2023 feasibility study outlined plans to convert SEPTA’s bus terminals into hydrogen storage and refueling stations to serve its hydrogen-powered bus fleet. The report claims that liquid hydrogen storage and fueling for their bus fleet is feasible at six of their eight bus depots. The hydrogen fueling scenario assumed for each site involves purchase by SEPTA of liquid hydrogen, to be delivered to each site by tanker truck. At each depot the liquid hydrogen would be transferred from the tanker truck to an on-site liquid storage tank(s) with capacity for 1 – 2 days of bus fueling.

Between four and ten tanker truck deliveries of liquid hydrogen would be required per week depending on the depot. The liquid hydrogen would be pumped from the storage tank(s), evaporated, and delivered to on-bus hydrogen tanks as a high-pressure gas via one or more hydrogen dispensers. SEPTA’s largest depot (Midvale) would require 45,000 gallons of liquid hydrogen storage (3 tanks). The estimated cost of installing the hydrogen storage and fueling infrastructure ranges from $6.5 million at the smallest depot to $16.1 million at the largest depot.

Why should I be concerned?

Hydrogen gas is highly flammable and burns with an almost invisible flame in addition to being colorless, odorless, and tasteless. The flammability and potentially explosive attributes of hydrogen makes it very dangerous to handle, transport, and store. The lack of  a visible flame, odor, or taste makes it very hazardous for workers and any residents in the vicinity because they would be unaware when a release has occurred.[1]

Hydrogen gas contains the smallest and lightest molecule, which increases the probability of leaks through small holes and materials. In other words, due to its low viscosity, hydrogen is much more prone to leak from infrastructure than other hydrocarbons. Hydrogen leaks approximately three times faster than natural gas and five times faster than propane on a volumetric basis.[2] Fires and explosions have occurred in various components of hydrogen systems as a result of leaks that can quickly meet a variety of ignition sources.

These inherent properties of hydrogen pose serious public safety risks, especially in densely populated areas such as Philadelphia. For instance, three of the bus depots proposed for hydrogen storage are directly next to public parks, one is adjacent to an elementary school, and one is next to Cobbs Creek. Many residences and businesses are also in the vicinity of these bus depots, along with other sensitive features like train routes and the PGW gas plant. An accidental hydrogen release or explosion has the potential to be catastrophic. There is an obvious need for a comprehensive safety analysis, for special hazardous materials emergency response training, and for public disclosure of the potential dangers of hydrogen in the city. People should know and understand the safeguards that are in place and the responses that would be activated to protect the public, infrastructure and the environment in the case of a release of hydrogen.

There does not appear to have been any public participation in the decisions regarding this proposal so far, and the public is seemingly unaware of these plans and the risks of transporting, storing, and using hydrogen in their communities. This is a serious flaw in SEPTA planning since public participation is an essential component of good planning and without it, people are left uninformed and without a way to give valuable input into the decisions that are made that have substantial impacts on their lives.

It must be noted that because hydrogen leaks throughout its life cycle, while in transit and in storage and is emitted when it is created, the indirect greenhouse gas effects of direct hydrogen gas releases will amplify and extend methane in the atmosphere.[1] Methane is 86 times more efficient than CO2 at trapping heat over a 20-year period, making it the most potent of the major greenhouse gases.[2] The extension of the life of methane substantially undermines the reduction of greenhouse gas emissions that is necessary to tackle the climate crisis.

Also noted is that the hydrogen that will be used by SEPTA during this testing and pilot period cannot be claimed to be “green”. SEPTA plans buy the hydrogen from Plug Power. The Plug Power website states “Plug uses electrolyzer and electricity made from renewable sources like wind, solar, hydro-electric, and nuclear power to split water molecules into hydrogen and oxygen.” This mix of energy sources contains hydroelectric power which emits substantial greenhouse gases to the atmosphere from reservoirs[3], primarily methane. The hydroelectric power used to make hydrogen by Plug Power is not green; it is a greenhouse gas emitter that will add to our burden of climate-destroying greenhouse gas emissions.

The 2021 Pennsylvania Climate Action Plan set a goal based on Governor Wolf’s Executive Order – a 26% reduction in net GHG emissions statewide by 2025 from 2005 levels.[4] President Biden has set a goal of reducing the nation’s greenhouse gas emissions by 50-52% below 2005 levels by 2030.[5] The deep reduction of greenhouse gas emissions is considered the linchpin to slow atmospheric warming and the climate impacts that result, according to the final report from the Intergovernmental Panel on Climate Change Report.[6] Hydrogen energy and its life cycle of greenhouse gas emissions used to power buses does not move us towards these global and local goals, it actually can be expected to dig us deep into the climate crisis hole. SEPTA’s use of the words “zero emissions” is misleading the public into thinking that these plans are benefiting the climate crisis when in fact they would be making it worse. The public must be made aware so they have an opportunity to speak up and protect their communities and the environment.

SEPTA is shown as a partner of the proposed MACH2 hydrogen hub; it is listed and mapped as a “transportation application” on the MACH2 website.[7] The hydrogen bus project may become an active end use of the hydrogen that MACH2 would produce if the price of the hydrogen is competitive with the sources that SEPTA uses to purchase hydrogen. As the SEPTA plan moves forward, the connection between the proposed MACH2 Hydrogen Hub and the current SEPTA hydrogen bus project will be made transparent, unlike the present where this connection is kept publicly unclear. For now, this is an example of how the MACH2 hydrogen hub is not only in the planning phase as MACH2 leadership claims but is actually materializing in Philadelphia as an end use hydrogen project without public engagement or discussion, even without public awareness, in violation of what MACH2 is required to do by the U.S. Department of Energy (DOE) and the Community Benefits Plan process supposedly being implemented by DOE’s Office of Clean Energy Demonstrations.

DRN has submitted a Right to Know Law Request with SEPTA to get more information and will be adding information to this web page as we gather it.


[1] https://www.rechargenews.com/energy-transition/-hydrogen-unlikely-to-play-major-role-in-road-transport-even-for-heavy-trucks-fraunhofer/2-1-1162055

[2] Myhre, G. et al. 2013. Anthropogenic and Natural Radiative Forcing. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Stocker, T.F., D. Quin, G.K. Plattner, M.Tignor, S.K. Allen, J. Boschung, A. Nauels, Y. Xia, V. Bex, and P.M. Midglet (eds). Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA. and https://en.wikipedia.org/wiki/Global_warming_potential 

[3] https://www.theguardian.com/sustainable-business/2016/nov/06/hydropower-hydroelectricity-methane-clean-climate-change-study

[4] PA Climate Action Plan, PADEP, et al, 2021. 7200-RE-DEP 548 9/2021 G2515

[5]  https://www.whitehouse.gov/climate/

[6] https://www.ipcc.ch/assessment-report/ar6/

[7] https://mach-2.com/about-mach2