The Future of Public Transport is Fuelled by Hydrogen

Jamie Locke-Jones
Wednesday 4 May 2022

Our world, unfortunately, runs in a highly unsustainable manner: burning and emitting carbon dioxide at huge rates in our industries, our leisurely activities, and our transportation. In an era defined by the threat of climate change, the importance of discovering and utilising renewable energy sources cannot be understated. From the School of ChemistryProfessor John Irvine and Dr Martin Smith have been crucial to our national response to this challenge, providing valuable industry advice and policy suggestions to help implement hydrogen fuel into Scottish public transport.

The case for hydrogen

While electric cars are increasingly popular when it comes to private transport, hydrogen has a useful role to play in meeting the greater energy demands of public transport. This is due to hydrogen’s high energy value, which allows for a greater range of transport if tied with on-board storage of fuel. Electricity, on the other hand, requires for vehicles to be charged at outlets: an element incompatible with public transport, which ideally operates throughout most of the day with only short breaks. One solution is to introduce centralised hydrogen refuelling depots for public transport vehicles, utilising hydrogen generated via renewable sources. Thus, hydrogen fuel in public transport is both efficient and plausibly low carbon.

Prof. Irvine’s expertise on fuel cells and electrolysers – required for hydrogen fuel development – has been key to progressing the research of hydrogen fuel as a potential source for public transport. Irvine, leading the Engineering and Physical Sciences Research Council Supergen project Delivery of Sustainable Hydrogen, along with Smith, are pioneering new technologies for hydrogen fuel’s rollout. 

Implementing hydrogen in Scotland’s public transport

The discoveries Irvine and Smith made regarding hydrogen fuel production have implications far beyond the lab; both scientists are technical advisors on the use of hydrogen for public transport in Scotland. 

Scotland has already started to decarbonise. In 2015, Aberdeen City Council assembled the largest hydrogen-powered fleet of buses in Europe, alongside two fuelling stations. The buses have since carried over 1.5 million passengers more than a million miles around the city. This has caused a significant decrease in CO2 and NOxemissions, bringing cleaner air to Aberdeen. 

Since 2011, Smith has been working on the HySeas program, helping to deliver the world’s first hydrogen-powered zero-emission ferry service. With a ferry that is fully powered by renewable hydrogen now under construction in Glasgow, the project promises a literal sea-change in public transport that was recognised when the project won the 2019 Innovation of the Year award at The Green Awards.

Irvine’s work culminated in the Scottish Government publishing the Scottish “Hydrogen Policy Statement”, which commits Scotland to the Hydrogen Accelerator programme. This is a St Andrews based project focused on linking academic, public, and commercial interests regarding hydrogen deployment, providing expertise as required across Scotland. The programme is a key player in helping Scotland achieve its net-zero target by 2045, and contributes to the phasing out of petrol and diesel cars and vans by 2032.

In November 2021 the project unveiled one of its most impressive developments at COP26: a prototype hydrogen train, showcased to invited guests from around the world. The project converted and re-used a 40-year-old three car class 314 train, demonstrating the potential to clean up public transport emissions without commissioning an entirely new fleet of vehicles, saving materials and decreasing the cost of clean energy. The development is particularly important for train lines in Scotland which would prove very difficult or impossible to electrify, either geographically or financially. This development pushes hydrogen closer to the centre of Scottish efforts to decarbonise public rail transport by 2035.

Irvine and Smith’s work is instrumental in Scotland’s fight in mitigating the effects of climate change. A sustainable, green public transport system is a green foundation, propelling the rest of industry to follow suit. 


This work contributed to the University of St Andrews’ REF 2021 submission.

The Research Excellence Framework (REF) is a system which assesses research at UK Higher Education Institutions by discipline, based on three elements: outputs, impact and environment. This blogpost is based upon an impact case study that contributed to St Andrews’ outstanding results this REF cycle. Visit REF to view the submitted case study in the UKRI’s impact case study database.

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