Expert viewpoint - Hydrogen at scale: balancing innovation and safety
As the world accelerates its shift towards sustainable and renewable energy, hydrogen is increasingly recognized as a critical component of our future energy systems. Praised for its clean-burning properties and potential to decarbonize sectors that are difficult to electrify, hydrogen may help solve some of the energy transition’s most difficult challenges. However, hydrogen also brings unique safety concerns that need to be carefully managed.
Understanding hydrogen
Understanding hydrogen’s distinct characteristics is essential to ensuring its safe integration into our energy system. Unlike more conventional fuels, hydrogen’s properties pose specific safety challenges that require tailored management strategies.
- Broad flammability range: Hydrogen's wide flammability range - from 4% to 75% by volume - far exceeds that of natural gas, which ignites in a narrower range of 5.3% to 15%. This expansive flammability range means hydrogen can more easily form combustible mixtures with air, increasing the likelihood of ignition under a broader range of conditions.
- Low ignition energy: Hydrogen requires very little energy to ignite - just 0.020 millijoules (mJ), compared to natural gas's 0.290 mJ. This low threshold means even a minor static charge can ignite hydrogen, necessitating stringent controls to prevent accidental ignition, particularly in environments with electronic equipment or human activity.
- High burning velocity and explosion risk: Hydrogen burns at a speed of 3.2 meters per second, which is significantly faster than natural gas. This rapid flame spread can lead to a higher risk of explosive pressure build-up, requiring robust containment and emergency response measures to prevent potentially devastating explosions.
- Rapid leakage and dispersion: Due to its low density and high diffusivity, hydrogen leaks more rapidly than methane, dispersing quickly into the atmosphere. While this rapid dispersion can reduce the risk of large, ground-level gas clouds, it also means that any leak must be quickly detected and controlled to prevent ignition, especially in enclosed spaces.
- Dispersion dynamics: Although hydrogen disperses quickly into the air, reducing the chance of lingering hazardous gas clouds, it can still accumulate in confined spaces, posing a significant fire and detonation risk. Understanding these dynamics is key to developing effective safety measures for hydrogen use.
These characteristics highlight the importance of implementing comprehensive risk management strategies as hydrogen technology scales up. While hydrogen’s properties necessitate rigorous safety protocols, they also offer opportunities for risk mitigation, particularly in terms of rapid dispersion. A nuanced understanding of these traits is vital for safely incorporating hydrogen into the global energy framework, essential for meeting climate goals.
Navigating safety in hydrogen risk management
Ensuring the safe deployment of hydrogen requires a multi-layered approach to risk management. Each layer must serve as a barrier to prevent hazards from leading to incidents, with the understanding that each layer has potential vulnerabilities. The cumulative effect of these barriers significantly reduces the likelihood of catastrophic failure.
- Avoidance: While completely eliminating hydrogen hazards is impractical given its critical role in the energy transition, efforts can be made to minimize hydrogen’s presence in vulnerable areas. This might involve reducing storage quantities in high-risk zones or relocating infrastructure away from populated regions.
- Prevention: When avoidance is not possible, the next best strategy is to prevent hydrogen from escaping its containment. This involves rigorous engineering practices, the use of high-quality materials, and strict adherence to industry standards to minimize the risk of leaks.
- Control: If a leak does occur, control measures are vital to limiting the scale and duration of the incident. Gas detection systems, emergency shutdown procedures, and rapid isolation of the affected area are critical to preventing small leaks from escalating into major events.
- Mitigation: Protecting people and assets is the focus of mitigation efforts. This includes using fire-resistant materials, installing ventilation systems to disperse hydrogen, and implementing emergency response protocols to ensure swift action in the event of an incident.
- Emergency Response: The final line of defense is a comprehensive emergency response plan. This includes evacuation procedures, coordination with first responders, and other measures to contain and manage the situation effectively when all other controls have failed.When avoidance is not possible, the next best strategy is to prevent hydrogen from escaping its containment. This involves rigorous engineering practices, the use of high-quality materials, and strict adherence to industry standards to minimize the risk of leaks.
DNV plays a key role in helping the hydrogen industry develop and implement these safety strategies. Through our extensive range of services, we assist clients in navigating the complexities of hydrogen risk management, from design and procedural controls to emergency response planning.
Supporting hydrogen safety through innovation and standards
As hydrogen technologies evolve, the regulatory frameworks and standards that govern them need to evolve as well. These regulations must be robust yet adaptable to ensure that hydrogen can be safely integrated into energy systems worldwide.
Organizations like the International Organization for Standardization (ISO) and the European Committee for Standardization (CEN) are leading efforts to create technical guidelines for hydrogen’s safe use. However, gaps remain, and continuous updates are necessary to keep pace with technological advancements and emerging risks from new large-scale designs.
DNV contributes significantly to this area through the management of Joint Industry Projects (JIPs) and the development of best practices that often serve as the foundation for new standards. Recent publications by DNV, such as the service specification for Verification of power-to-X facilities DNV-SE-0656 and the standard Electrolyser systems DNV-ST-J301, highlight our commitment to supporting the hydrogen industry with cutting-edge solutions that prioritize safety.
Additionally, DNV is at the forefront of addressing challenges in hydrogen storage, for instance in salt caverns, which are critical for large-scale storage but present unique safety concerns. By spearheading initiatives to develop updated safety standards, DNV is helping to ensure that hydrogen storage facilities can operate safely and efficiently.
8/27/2024 6:00:00 AM