The deployment of hydrogen-fuelled buses has witnessed a modest start in the US, with hydrogen buses constituting only 3.1 per cent of the total zero-emission buses (deployed or planned to be deployed) across the country. The deployment is expected to receive a considerable boost in the coming decade, with the ‘scalability’ factor outweighing the high cost of procurement. While the cost of purchasing hydrogen buses is one of its biggest deterrents to its widespread adoption, the ability to scale operations is its biggest selling point. The provision of adequate hydrogen fuelling stations is one of the most crucial aspects while considering the scalability of hydrogen buses. The US government has introduced several programmes to ensure the implementation of adequate refuelling infrastructure, thereby encouraging transit agencies and operators across the US to invest in hydrogen buses.

Box 1 provides details of the programmes promoting the deployment of hydrogen buses and fuelling stations in the US.

Box 1: Programmes promoting the deployment of hydrogen buses

The Clean Transit for America Plan

On May 4, 2021, Senate Majority Leader Chuck Schumer and Chairman of the Senate Committee on Banking, Housing and Urban Affairs Sherrod Brown unveiled the new Clean Transit for America Plan, which provides USD73 billion to aid the transition of the country’s public transit systems to zero-emission fleets. The funds will be used to replace 70,000 mass transit buses and 85,000 cutaway vehicles and transit vans with clean energy vehicles. The plan will prioritise funding for areas with the worst air quality and help combat climate change, improve air quality, and establish a transit workforce training programme that will create good-paying union jobs. 

The funds will be made available by increasing the funding for the Federal Transit Administration’s (FTA’s) Low or No Emission Vehicle Program, the main aim of which is to support the transition of the transit fleet in the country to the lowest polluting and most energy-efficient transit vehicles. The FTA has distributed over USD485 million for hybrids, battery-electric, and hydrogen fuel cell buses via the Low or No Emission Vehicle Program. 

The plan was announced shortly after the launch of President Biden’s American Jobs Plan, which calls for USD621 billion in transportation investment and which is expected to double the federal investment in public transit. 

California Zero-Emission Vehicle (ZEV) Action Plan (2018)

The ZEV Market Development Strategy is meant to help California deliver zero-emission benefits to all Californians. In January 2018, the action plan was set into motion with the aim of boosting the supply of ZEVs and increasing the provision of charging and refuelling stations in California. The plan has set targets of creating 200 hydrogen fuelling stations and 250,000 electric vehicle chargers to support 1.5 million ZEVs on California roads by 2025, on the path to 5 million ZEVs by 2030. The initiative is designed to focus multi-stakeholder efforts on deploying charging and fuelling infrastructure as well as making ZEVs increasingly affordable to own and operate. The actions outlined in the plan are grouped under six broad goals that the state government is currently implementing or plans to implement to help expand the ZEV market. These goals are: 

– Achieving mainstream consumer awareness of ZEV options and benefits
– Making ZEVs an affordable and attractive option for drivers
– Ensuring convenient charging and fuelling infrastructure for the greatly expanded use of ZEVs
– Maximising economic and job opportunities arising from the use of ZEV technologies
– Bolstering the growth of the ZEV market outside California
– Leading by example by ensuring the integration of ZEVs into the state government’s plans and strategies  

National Fuel Cell Bus Program 

The National Fuel Cell Bus Program is a cooperative initiative between the US government and the private sector to advance the commercialisation of fuel cell technology in US transit buses. Over USD60 million has been awarded to date for competitively selected projects while industry has provided over USD60 million in additional private commitments. The main goals of the National Fuel Cell Bus Program are: 

– Facilitating the development of commercially viable fuel cell bus technologies
– Improving transit bus efficiency and reducing petroleum consumption
– Reducing transit bus emissions
– Establishing a globally competitive US industry for fuel cell bus technologies
– Increasing public awareness and acceptance of fuel cell vehicles 

Transitioning to ZEBs

A new report from the Center for Transportation and the Environment (CTE) indicates that the transit bus fleet in the US could transition to full ZEVs by 2035. The total cost of this transition is expected to range between USD56.22 billion and USD88.91 billion. The report assumes that a combination of battery-electric vehicles and hydrogen fuel cell vehicles will be deployed to meet the transition target. In both the low-cost and high-costs scenarios, the vehicles themselves account for between 51 per cent and 59 per cent of the costs, followed by infrastructure, technical assistance, and FTA innovation and bus-testing costs.

Currently, hydrogen fuel cell buses are the second most common type of zero-emission buses in the US, after electric buses. Out of the total 2,790 buses (deployed or planned to be deployed), only 3.1 per cent (87 buses) are hydrogen fuel cell buses. The modest deployment of hydrogen buses can be attributed to the higher cost of procurement, lack of supporting infrastructure, and individual agency preference. However, many transit agencies have announced plans to extend various bus routes, which is expected to increase the demand for hydrogen fuel cell buses in the future. While this is expected to reduce the difference between the number of battery-electric buses and hydrogen fuel cell buses that are deployed, electric buses are expected to continue to be the dominant type of zero-emission buses in the country.

Table 1 gives details of the state-wise distribution of hydrogen fuel cell buses and total number of zero-emission buses deployed across various states in the US.

StateFuel Cell BusesTotal Zero-emission Buses
Table 1: ZEB distribution by state
Source: Calstart

Figure 1 gives a state-wise breakdown of hydrogen buses as a percentage of the total number of zero-emission buses across eight states in the US.

Figure 1: Hydrogen fuel cell buses as a percentage of total zero-emission buses
Source: Global Mass Transit Research

In terms of absolute numbers, California leads among all US states in the deployment of hydrogen buses (deployed or planned to be deployed). However, in terms of percentage of the total number of zero-emission buses deployed, hydrogen buses comprise a mere 4.48 per cent (52 out of 1,160 zero-emission buses).

In comparison, Ohio has the maximum percentage of hydrogen buses (deployed or planned to be deployed) in the US, with 24 hydrogen buses out of a total 61 zero-emission buses. In September 2017, the Stark Area Regional Transit Authority and the Renewable Hydrogen Fuel Cell Collaborative released a road map that outlined a 15-year plan to deploy 135,000 fuel cell vehicles – trucks, buses, and cars. In addition to vehicle deployment, the roadmap described a process of moving towards renewable hydrogen production and estimated the potential for setting up 250 hydrogen stations, thereby strengthening Ohio’s fuelling and manufacturing infrastructure. Ohio has a robust network of fuel cell component and material suppliers, thereby making it the third largest state for fuel cell electric buses in the nation. The high percentage of hydrogen buses in Ohio can be attributed to the availability of supporting infrastructure and state-level plans promoting the deployment of fuel cell vehicles.

Advantages of transitioning to hydrogen buses

Fuel cell buses use hydrogen to generate electricity as opposed to battery-electric buses that store electric energy on board, thereby making it possible to refuel hydrogen fuel cell buses rather than recharging them. Hydrogen buses have three main advantages over battery-electric buses. Figure 2 outlines these benefits.

Figure 2: Benefits of hydrogen fuel cell buses
Source: wardsauto

The main impediment to the deployment of hydrogen fuel cell buses is the cost of procurement of the buses. The cost of procurement of one hydrogen bus is significantly more than that of a battery-electric bus (USD1.2 million for the former compared to USD750,000 for the latter). However, with adequate supporting infrastructure in place, the cost of operating a hydrogen fuel cell bus is the same or less than that of operating a compressed natural gas (CNG) or diesel bus.

Having established that the cost of procuring hydrogen buses is significantly high, it is also important to consider the cost of operating hydrogen buses. For example, the SunLine Transit Agency based in Thousand Palms, California, provides public transit services to Coachella Valley in Southern California. SunLine operates 15 fixed routes (three trunk lines and 12 local routes), one commuter route (between Palm Desert and Riverside), and one express route (between Desert Hot Springs and Palm Desert). The current bus fleet consists of 86 fixed-route buses, 62 CNG buses, 20 hydrogen fuel cell buses, and four battery-electric buses. The SunLine Transit Agency spends USD0.42 per mile to operate fuel cell buses and USD0.48 per mile to operate CNG buses. Hence, while the cost of procuring a hydrogen bus may be significantly higher, the return on investment on a hydrogen bus, offered by cheaper operating cost, may outweigh the higher cost of procurement in the long run. Nevertheless, it is important to note that the availability of supporting infrastructure is crucial in determining the extent to which operating costs can outweigh procurement costs. The SunLine Transit Agency has invested in hydrogen refuelling infrastructure and makes its own hydrogen fuel, thus significantly reducing its fuel costs.

Figure 3 outlines the scalability of hydrogen fuel cell buses in terms of effort and cost in comparison to electric buses.

Figure 3: Scalability of hydrogen fuel cell buses (FCEB)
Source: Center for Transportation and Environment (CTE)

Challenges of deploying hydrogen buses

Cost: Though the average cost of a hydrogen bus is decreasing, the cost at present is not sufficiently competitive with the costs of other bus technologies. Electric buses and conventional-fuel buses continue to offer more cost-effective purchasing options to transit authorities across the US.

Fuel cell system issues: Most problems with the fuel cell system are related to components of the “balance of plant” like air blowers and compressors.

Availability of parts: Fleet operators have experienced difficulties in procuring parts. Agencies have attempted to address this issue by producing the parts internally or by ordering parts directly from a manufacturer rather than using a distributor. In the future hydrogen buses are planned to have parts that can be replaced with conventional bus parts, thereby improving availability and lowering costs.

Range issues: Hydrogen bus operators have reported difficulties in completely filling hydrogen tanks, thereby significantly compromising the bus range, which largely depends on the ability to fill the tank completely.

Access to and cost of hydrogen fuel: Hydrogen fuel is often costly and difficult to access. Prior to introducing hydrogen fuel cell buses, it is imperative for transit authorities to start working with hydrogen fuel suppliers. Additionally, transit authorities should also plan for future fleet expansion to reduce future costs.

Recent developments

Several initiatives have been planned to accelerate the deployment of hydrogen buses in the US since January 2021.

Table 2 provides details of the initiatives since January 2021.

May 3, 2021BAE Systems announced plans to collaborate with Plug Power to offer hydrogen-based electric propulsion systems for transit buses. BAE Systems will integrate Plug Power’s fuel cell engines into its electric drive systems to power buses. The technology is expected to increase efficient, reliable, and emission-free options for transit operators. 
April 8, 2021The Stark Area Regional Transit Authority (SARTA) partnered with NICE America Research, the US-based research and development arm of China Energy, to test a mobile submerged pump liquid hydrogen refuelling unit. The demonstration, spanning a period of three months, has been undertaken in real-world conditions for the first time. The submerged pump mobile refuelling station (provided by NICE America Research) has been installed at SARTA’s main offices and will be used to refuel the transit authority’s 10 buses and five hydrogen-fuelled Pro-Line vehicles. The system is less expensive to construct, and less expensive to operate once built, compared to conventional hydrogen refuelling systems. 
February 8, 2021Eleven companies in the US formed a coalition called Hydrogen Forward to focus on advancing hydrogen-related developments across the country. The founding members are Air Liquide, Anglo American, Bloom Energy, CF Industries, Chart Industries, Cummins Inc., Hyundai, Linde, McDermott, Shell, and Toyota. The coalition aims to support policies that accelerate the transition to new clean energy and to establish a strategy for the development of hydrogen technology and related infrastructure. The creation of this coalition is expected to boost the deployment of hydrogen buses in the US. 
Table 2: Recent developments promoting deployment of hydrogen buses (2021)


The deployment of hydrogen fuel cell buses in the US depends on three major factors—cost of procurement, government funding, and adequate supporting infrastructure. While the deployment has been relatively slow owing to the cost of procurement, the long-term use of hydrogen buses in states like Ohio has demonstrated a significant return on investment. Hydrogen buses have twice as much range as battery-electric buses and have a shorter refuelling time. Further, hydrogen buses are easier to scale up since one hydrogen refuelling station can handle larger volumes than a single charging post. The existing level of deployment of hybrid buses, albeit modest, has been accompanied with the implementation of adequate supporting infrastructure, especially in states like California and Ohio. The availability of supporting infrastructure coupled with the ability of hydrogen buses to be scaled is expected to pave the way for accelerated deployment in the future. Further, the cost of procuring hydrogen buses, which is one of its biggest drawbacks, has been consistently declining over the decade. The average cost of procuring a hydrogen bus is currently USD1.27 million, which is already 49 per cent lower than the cost of a hydrogen bus purchased in 2010. The price is expected to further decrease to USD850,000 in the next five years. Lastly, government plans and programmes, combined with individual state-level carbon-emission goals, are expected to give the deployment of hydrogen buses an additional boost, thereby ensuring that hydrogen buses constitute a larger proportion of zero-emission buses deployed in the US.

The article has been sourced from Global Mass Transit