Decarbonisation Technology - May 2023 Issue

Safety, risks, and hazards of hydrogen

The safe use and distribution of natural gas are fully understood, but a similar level of technical understanding is now required for the key properties of hydrogen

Sarah Kimpton DNV

T here is an emerging consensus that low-carbon and renewable hydrogen will play an important role in a future decarbonised energy system. How prominent a role remains uncertain, but various estimates point to hydrogen being anything from 10-20% of global energy use in a future low-carbon energy system. DNV’s Pathway to Net Zero has hydrogen at 13% of a net-zero energy mix by 2050 (DNV, 2021). Scaling global hydrogen use is beset by a range of challenges: availability, costs, acceptability, safety, efficiency, and purity. While it is widely understood that urgent upscaling of global hydrogen use is needed to reach the Paris Agreement, the present pace of development is far too slow and nowhere near the acceleration we see in renewables, power grid, and battery storage installations. Nevertheless, there is a great deal of interest among a range of stakeholders and the media in the promise of hydrogen. Yet some commentators are taking a careful, dispassionate look at the details behind hydrogen’s likely global growth pathway, including safety. Hydrogen properties Hydrogen is the most abundant element in the universe. However, on Earth it is found only as part of a compound, most commonly together with oxygen in the form of water but also in hydrocarbons. Hydrogen is the simplest of all the elements, but processes to produce it in pure form are not so simple; they are energy intensive and involve large energy losses, have significant costs, and can produce their own carbon emissions.

Safety, risks, and hazards Hydrogen is not new to society; it has been produced and used in large quantities for more than a century. However, this has mostly been in industrial environments where there is a good degree of control, and where facilities are managed by people who have a clear understanding of the potential hazards. The forecasted significant market growth of hydrogen as an energy carrier will introduce many new hydrogen facilities that are very different from those we have had in the past. Moreover, some of the facilities will be in much closer proximity to the public. They will be built and operated by new entrants who may not have relevant experience in hydrogen safety. Scaling global hydrogen use is beset by a range of challenges: availability, costs, acceptability, safety, efficiency, and purity Risk perception will be an important factor in acceptance of hydrogen use. Accidents involving hydrogen are likely to receive more media attention than comparable events with conventional fuels (at least initially). This could induce public resistance and prompt a more restrictive regulatory environment. The sensitivities to risk and risk perception will likely vary among sectors. However, they will be highest where the public is near the actual use of hydrogen, such as in aviation and domestic heating, and less so in more industrial-type applications, such as hydrogen storage.