A decade ago, hydrogen was heralded as an emerging clean energy source. But despite extensive promotion and governmental support from world leaders, including former US President Barack Obama, the use of hydrogen as an alternative energy source is not yet ubiquitous. This delay in adoption has largely been due to technology readiness and its associated high cost.

Technological progress

Hydrogen-based technology was not mature in 2008, and needed more time to undergo further efficiency improvements and cost reductions. During the past decade, significant financial resources have been spent on hydrogen energy research and development globally, allowing hydrogen to make a spectacular comeback. This time, it’s here to stay.

Global alliances

The growing environmental pollution and global governance initiatives, such as the 2015 Paris Agreement, support the case for adopting hydrogen as a clean and viable replacement for fossil fuels in transport, energy storage and power-to-gas applications. However, the transition to a hydrogen-based society will not be easy. It requires the development of a completely new infrastructure with consolidated action by various stakeholders, from equipment manufacturers and technology integrators to energy companies and government agencies.

On this front, the Hydrogen Council was formed at the World Economic Forum Annual Meeting 2017 in Davos to accelerate the scaling up of hydrogen technology and facilitate the societal adoption of hydrogen. Initial founders of the Hydrogen Council include many large multinational corporations, notably 3M, Air Liquide, Alstom, Audi, BMW, Hyundai, Toyota and Shell.

Dangerous or safe?

Despite consolidated efforts by several leading global companies, the adoption of hydrogen remains difficult. One major reason is the public perception of hydrogen safety. An anonymous social media survey that asked two related questions and garnered 483 responses showed mixed public views of hydrogen as a safe energy source.

Only 49.5% of respondents believed that hydrogen is generally safe, while 31.4% viewed hydrogen as generally dangerous. Among those who believed hydrogen is safe, about 9.1% regarded it as very safe, while of those who doubted its safety, 4.1% thought it was very dangerous. The survey drives home the message that more work is needed to change the public perspective of hydrogen.

Image: Bart Kolodziejczyk

Dangerous?

The view that “hydrogen is dangerous” is most likely influenced by certain historic accidents, including the infamous Hindenburg disaster. In 1937, a hydrogen-filled German passenger airship caught fire and was destroyed as it attempted to dock in New Jersey. Of the 97 people on board, 36 died.

The disaster was the subject of spectacular newsreel coverage, photographs and eyewitness accounts, and it effectively ended the era of the airship. The cause of the disaster remains a moot point. Several hypotheses have been put forward, including one claiming a static spark ignited hydrogen which caused the explosion.

A more contemporary catastrophe is the 1986 Space Shuttle Challenger launch. A NASA space shuttle disintegrated after take-off, killing all seven people on board. The launch was broadcast live with footage replayed worldwide in subsequent news reports. Although investigations revealed that failed O-ring seals were the main culprit and that the presence of liquid oxygen contributed to the explosion, the sight of the Challenger disintegrating mid-air cemented the danger of harnessing hydrogen in millions of minds around the globe.

Safe?

The public perceives hydrogen as highly flammable and explosive. Although this is true, hydrogen is safer than most commonly used fuels. For instance, hydrogen needs a higher minimum concentration than most common fuels to burn. Measured by percentage volume in air, hydrogen requires 4% in air to be flammable, compared to 0.6% for diesel fuel, 1.4% for gasoline, 1.2% for propane, 3.3% for ethanol and 5% for methane.

In terms of auto-igniting temperature, methane and hydrogen are again winners, as in the absence of a flame or spark, they only start burning at 580°C and 550°C respectively. These auto-igniting temperatures are higher than those of diesel, gasoline, propane, and ethanol, which are 210°C, 260°C, 480°C, and 365°C.

Surprisingly, 73.2% of participants in the social media survey gave a positive response to the second question about “willingness to using hydrogen-powered modes of transportation”. This result seems to contradict answers to the first question, which found that only 49.5% support hydrogen as a safe energy source.

The intriguing result comes from the initial “dangerous” group, with about half willing to cast away their fears to use hydrogen-powered transport. The exact reason for this discrepancy is unknown and should be further examined. Perhaps small-scale hydrogen-based implementations are not deemed as dangerous. Also, prior knowledge that government agencies will only allow safe modes of public transport could have mitigated this fear.