WHAT ARE SOME OF THE CHALLENGES OF HYDROGEN AS AN ENERGY SOURCE?
The overarching challenge to hydrogen production is monetary cost reductions – to make it competitive with conventional transportation fuels. 
The initial challenge of using hydrogen as a fuel lies in the efficient extraction of H2 from the various sources. Although abundant, hydrogen is almost always found as part of another compound and must be separated from the compounds that contain it before it can be used in vehicles. Once separated, hydrogen can be used along with oxygen from the air in a fuel cell to create electricity through an electrochemical process. 
While hydrogen allows for zero-emission electric vehicles, the hydrogen source and production process must also be considered, in terms of environmental and health costs.  While the least expensive source of hydrogen is from natural gas, natural gas is a non-renewable hydrocarbon. Solar, wind, and nuclear energy are examples of carbon-free renewable sources of hydrogen. 
Also, the cost of fuel cells will have to decrease substantially, without compromising vehicle performance. 
Distribution infrastructure is a challenge. There is no standardized distribution system for hydrogen. Building a new hydrogen pipeline network involves high initial capital costs.  Currently, most hydrogen utilized by industry is produced close to where it is used. Producing hydrogen transportation fuel at the point of end-use—at fueling stations, for example—cuts distribution costs but increases production costs, due to the cost to construct on-site production capabilities. Producing hydrogen fuel centrally in large plants cuts production costs but boosts distribution costs. 
In the U.S., production of hydrogen-fueled cars is limited because people won't buy those cars if refueling stations are not easily accessible, and companies won't build refueling stations if they don't have customers with hydrogen-fueled vehicles. So, states can’t just rely on market forces to drive hydrogen as a transportation fuel. The State of California has a program to help fund the development of publicly accessible hydrogen refueling stations throughout the state to promote a consumer market for zero-emission fuel cell vehicles.
Storage is also a challenge. There is no standardized method of storage for hydrogen. Hydrogen’s energy content by volume is low, which makes storage a challenge because it requires high pressures, low temperatures, or chemical processes to be stored compactly.  Additional challenges associated with energy storage are captured below:
- "Weight and Volume. The weight and volume of hydrogen storage systems are presently too high, resulting in inadequate vehicle range compared to conventional petroleum fueled vehicles. Materials and components are needed that allow compact, lightweight, hydrogen storage systems while enabling mile range greater than 300 miles in all light-duty vehicle platforms.
- Efficiency. Energy efficiency is a challenge for all hydrogen storage approaches. The energy required to get hydrogen in and out is an issue for reversible solid-state materials. Life-cycle energy efficiency is a challenge for chemical hydride storage in which the byproduct is regenerated off-board. In addition, the energy associated with compression and liquefaction must be considered for compressed and liquid hydrogen technologies.
- Durability. Durability of hydrogen storage systems is inadequate. Materials and components are needed that allow hydrogen storage systems with a lifetime of 1500 cycles.
- Refueling Time. Refueling times are too long. There is a need to develop hydrogen storage systems with refueling times of less than three minutes over the lifetime of the system.
- Cost. The cost of on-board hydrogen storage systems is too high, particularly in comparison with conventional storage systems for petroleum fuels. Low-cost materials and components for hydrogen storage systems are needed, as well as low-cost, high-volume manufacturing methods.
- Codes and Standards. Applicable codes and standards for hydrogen storage systems and interface technologies, which will facilitate implementation/commercialization and ensure safety and public acceptance, have not been established. Standardized hardware and operating procedures, and applicable codes and standards, are required.
- Life-Cycle and Efficiency Analyses. There is a lack of analyses of the full life-cycle cost and efficiency for hydrogen storage systems."
Updated June 2022 by Erin Bennett