Public concerns over hydrogen safety represent a barrier to the large-scale market uptake of hydrogen technologies. What are the main safety issues involved with the use of hydrogen as an energy carrier?

With the required new solutions for hydrogen as an energy carrier and energy storage medium, new operational conditions are implied. Pressure of around 70 MPa is applied for on-board storage in hydrogen-powered vehicles and large-scale distribution of hydrogen seems to be most economical in the liquid state at -250°C. From this, we can easily derive that the safety of light pressure vessels, the behaviour of cryogenic hydrogen releases and mass storage of hydrogen in general, including material compatibilities at these conditions, are the main safety issues.

However, as long as the accidental scenarios are located in the free environment the intrinsic properties of hydrogen show considerable advantages with regard to safety compared to conventional fuels or energy carriers. Only in combination with enclosure, e.g. use of hydrogen indoors, such as in tunnels, garages etc., the above issues may result in more severe hazards.

For more details, I recommend taking a look at the document “STATE-OF-THE-ART AND RESEARCH PRIORITIES IN HYDROGEN SAFETY” edited and periodically reviewed by the International Association for Hydrogen Safety HySafe in close cooperation with the European Commission’s Joint Research Centre (JRC) and industry representatives. An updated version of this document will be presented at the International Conference for Hydrogen Safety in Yokohama, Japan, on 19-21 October this year.

What projects are being implemented in the European Union to address these issues and to increase public acceptance of hydrogen?

In the previous Framework Programmes there were several projects addressing safety, standards and regulation, and awareness (at least partially). Some examples are EIHP, NaturalHy, HYTHEC, HarmonHy, HySociety, HYPER, and HyApproval. However, in 2003 with the Network of Excellence (NoE) instrument, a unique effort to integrate the fragmented work on hydrogen safety was initiated by the EC through the NoE HySafe.

Now, within the framework of the Fuel Cells and Hydrogen Joint Undertaking (FCH JU) several projects again address safety and acceptance-related issues. The most relevant are H2TRUST, HyTransfer, HyFacts, HyIndoor, FireComp, HyPactor, HySEA, as well as the research infrastructure project H2FC, supported by the FP7 Capacities program.

In my personal view, the cross-cutting nature of the safety, awareness and acceptance topics is not fully met through such a project-based approach. What is required is a real cross-cutting, holistic approach to exchange and sustainably maintain experience and to continue to improve the state-of-the-art. In this regard, the JRC and IA HySafe are currently investigating measures to enable extracting relevant information from projects, feeding valuable experience back into new projects and disseminating knowledge and expertise in a consolidated way to the public via a Hydrogen Safety Expert Panel. Incidentally, the US Department of Energy (DoE) successfully established a similar group in the US several years ago.

What have been the main achievements in recent years towards creating a culture of safety in the hydrogen sector, and what are the main challenges remaining?

Besides the important results of the above mentioned EC-funded projects and national projects, including also US and Japanese work, the safety community has fostered its links via common efforts regarding new international standards in ISO TC 197. In particular, there will be a new standard for refuelling stations, which is based on broad international consent and will refer to new commonly developed tools for risk assessment (e.g. HyRAM).

The corresponding European research community, established by the NoE HySafe, is being further integrated by the joint research work of the H2FC project and its support of highly relevant user projects at the partners’ facilities.

Another important building brick for a safety culture is open communication within the recently formed safety task (Task 37) of the International Energy Agency Hydrogen Implementing Agreement (IEA HIA), which focuses international research cooperation on the most critical issues.

Lastly, but no less importantly, IA HySafe provides further critical elements with the:

• International Conference for Hydrogen Safety,
• Research Priorities Workshops,
• HIAD incident database (in cooperation with the JRC), and
• several educational activities.

One element that is missing in the European context is a service for the provision of consistently updated state-of-the-art information on safety issues to any projects dealing with hydrogen physically. This would mainly support new players and SMEs, which are the key drivers of innovation in the hydrogen and fuel cell field. Additionally, an obligation to report incidents and accidents in EC co-funded work would help to build-up a knowledge base and a statistical resource. I consider sharing critical safety information to be a key to improving overall learning and to ensuring public and private investments in these new technologies.

What is the current focus of hydrogen safety research?

Efforts are currently directed at multiphase effects, in particular with liquid hydrogen releases, hydrogen blended to other fuels, fire safety of pressure vessels and associated testing procedures, quantitative risk assessment procedures, and human effects. In addition, the more fundamental issues of flame acceleration and deflagration-to-detonation transition continue to be further investigated, particularly for more realistic settings. On a more applied level, the risk reducing effectiveness of mitigation measures, like ventilation, represents another important focus.

How does the safety culture in the hydrogen sector in Europe compare with that in the rest of the world? Are there any best practices that Europe can learn from international experience?

We are seeing quite strong and strategic activities in US, driven by the US DoE, and in Japan, driven mainly by a strong belief in the hydrogen economy there. The central funding agencies there simply call for the required cross-cutting actions and mandate qualified and independent organisations to ensure consistent application of harmonised safety-related procedures and reporting. Consequently, one might expect the safety culture to be more mature in these regions, which are more hierarchically driven.

However, in a considerable number of technology fields associated with hydrogen and fuel cells European industry was and still is in a leading position, which is also due to the very highly-developed safety culture among European companies. The spread of this culture beyond the companies in question through a cross-cutting effort will further improve the overall situation in Europe. However, this has to happen based on a top-down approach, going beyond typical project limitations, making best use of existing infrastructures and communities that are ready to deliver.