Hydrogen has several advantages as a potential clean energy carrier, but it also faces several challenges and issues at the current stage of its development. Some of the main issues associated with using hydrogen as a fuel include:

1. Production: Most hydrogen is currently produced from fossil fuels, primarily natural gas, through a process called steam methane reforming (SMR). This process releases carbon dioxide (CO2) and methane emissions, which are potent greenhouse gases. To make hydrogen a truly clean fuel, it needs to be produced using low-carbon or renewable methods, such as electrolysis using green electricity.
2. Energy Efficiency: Hydrogen production, particularly from fossil fuels, can be energy-intensive, and this results in a lower overall energy efficiency compared to directly using electricity in electric vehicles or other applications. The energy losses in hydrogen production, storage, and conversion can be significant.
3. Storage and Transportation: Hydrogen is a low-density gas, which makes storage and transportation challenging. It either needs to be compressed at high pressures or liquefied at very low temperatures, both of which require energy and can lead to energy losses. Additionally, hydrogen can leak easily, making handling and transportation safety critical.
4. Infrastructure: There is currently limited infrastructure for hydrogen production, distribution, and refueling compared to conventional fossil fuels and even electric charging stations. Developing a comprehensive hydrogen infrastructure is costly and requires significant investment.
5. Cost: Hydrogen produced through conventional methods can be more expensive than fossil fuels or other alternative energy sources, making it less economically competitive. The cost of hydrogen production and the associated technology still needs to come down to become a more viable fuel option.
6. Green Hydrogen Availability: Green hydrogen, produced using renewable energy sources like wind or solar, is considered the most environmentally friendly option. However, it is still relatively expensive and not as widely available as grey or blue hydrogen (produced from fossil fuels with carbon capture and storage). Scaling up green hydrogen production is a major challenge.
7. Carbon Capture and Storage (CCS): Blue hydrogen, which is produced from natural gas with CCS, is often seen as a transitional solution to reduce emissions. However, the success of CCS technologies is uncertain, and the long-term environmental impact and cost-effectiveness of this approach are still being evaluated.
8. Safety Concerns: Hydrogen is highly flammable and can pose safety risks if not handled properly. Developing and implementing safe storage and transportation systems is crucial.
9. Material Compatibility: The use of hydrogen as a fuel can lead to issues related to material compatibility in various components, such as fuel cells, pipelines, and storage tanks, as hydrogen can cause embrittlement in some materials.
10. Regulatory and Standardization Challenges: Developing consistent regulations and standards for hydrogen production, storage, transportation, and utilization is a complex task that requires coordination among various stakeholders.

Despite these challenges, hydrogen remains a promising energy carrier for specific applications, especially in industries where electrification may not be as feasible, such as heavy transportation or industrial processes. Addressing these issues will be crucial for making hydrogen a more sustainable and widely adopted energy source in the future.