## 7 Discussion
### Limitations and Challenges in the Storage and Transport of Green Hydrogen  
Hydrogen is emerging as a key solution for the decarbonization of energy-intensive sectors such as heavy industry, long-distance transportation, and seasonal storage. The International Renewable Energy Agency (IRENA) estimates that global hydrogen production will need to increase five-fold by 2050, reaching 12% of final energy demand and contributing 10% to CO\({}_{2}\) emissions reductions by that same year. Green hydrogen, produced from renewable sources, is the main contributor to this growth [50].  
However, green hydrogen production faces significant challenges. Reliance on renewable energy sources such as wind and photovoltaics, while sustainable, can be expensive and difficult to access for countries with limited geographical access to renewable resources. Additionally, the intermittent nature of these large-scale energy sources can lead to fluctuations and instability in the electricity supply, posing a challenge to the efficient operation and lifespan of electrolyzers, as well as to the purity of the hydrogen produced. The transportation of green hydrogen constitutes another crucial hurdle in its value chain. While some authors suggest leveraging existing pipelines for the transport of hydrogen and natural gas blends as an efficient and cost-effective strategy for long distances, hydrogen can also be transported in high-pressure gaseous form, low-temperature liquid form, or via liquid organic carriers [59]. However, the transportation of high-pressure gaseous and low-temperature liquid hydrogen is costly and inefficient for large-scale regional coverage. In this regard, some authors propose that the transportation of blended hydrogen through gas pipelines will become an inevitable trend, with the potential to significantly reduce infrastructure costs. Some authors [59], meanwhile, emphasize the importance of bulk maritime transport for establishing a global green hydrogen supply chain, although they note that the considerable investment required and limited experience in this type of transport may require long-term supply contracts to secure financing for these projects. From an economic perspective, some authors have analyzed the potential of green hydrogen for transportation, but identified challenges in its widespread development, primarily its current lack of competitiveness compared to fossil fuels and blue hydrogen due to its expensive infrastructure and long lead times for the acquisition of electrolyzers. The authors in [12] corroborate these findings, noting that the current efficiency and costs of green hydrogen production, transportation, storage, and re-electrification technologies still represent significant obstacles to its widespread implementation.  
Finally, the safety of hydrogen transportation and handling is a key concern. Its potential to generate explosions in confined spaces due to leaks and ignition sources, coupled with its colorless and odorless nature, which makes it difficult to detect, and its ability to displace oxygen, represent significant risks. Despite the growing number of green hydrogen projects worldwide, knowledge about the behavior of hydrogen leaks and deflagrations in complex environments is still limited. Overcoming these technical, economic, and security challenges will be crucial to consolidating green hydrogen as a viable energy vehicle in the transition to a low-carbon economy.