Many energy experts will tell you about the almost unlimited potential that hydrogen has, some of them will even call hydrogen as the key fuel to clean energy future. Hydrogen is definitely one of the most acceptable fuels from environmental point of view. When hydrogen burns in air, it produces nothing but water vapor, meaning it is totally ecologically acceptable. There have been already some ideas from prominent energy experts on how hydrogen will soon replace gasoline, oil, natural gas, coal, and nuclear power, ensuring clean energy worldwide.
Hydrogen is by far the most abundant element in universe therefore it can't be depleted like fossil fuels can, and unlike the fossil fuels it is totally environmentally acceptable. And we have been already using hydrogen for couple of decades as the fuel to provide electricity for the space shuttles. So why then, with so many obvious advantages we don't use hydrogen as fuel much more than we currently do?
This is mostly because hydrogen production requires great deal of energy. The most common method of producing hydrogen is done via the catalytic steam reforming of methane, process that at the end results in hydrogen and carbon monoxide, and the carbon monoxide can be further reformed to produce more hydrogen if required. This does not only require great deal of energy but also contributes to the worldwide increase in global emissions of carbon dioxide, so the most common production of hydrogen definitely has some serious disadvantages that need to be solved in order to make hydrogen production more efficient.
One of the solutions to hydrogen production problem could be harnessing hydrogen by utilizing renewable energy sources like wind power and solar power. Some companies, like U.S. company Avālence LLC have used the process of electrolysis to convert water and electricity into high purity pressurized hydrogen gas that doesn't require a separate compressor, meaning it consumes significantly less energy for production. Avālence LLC announced how this process cuts capital costs by up to 50%, and operating costs by 20%.
The lower energy consumption in this case means that these hydrogen generating systems could be even powered by wind turbines or solar panels, and with this the disadvantage of emitting carbon emissions would also be canceled. Also, the hydrogen produced during inexpensive or excess power production periods can be easily stored and later distributed to stationary fuel cell generators to supply electricity during peak demand periods.
However, this technology has been so far completed only on small-scale units for residential use, and lot more researches is needed to make hydrogen production totally efficient from economic, as well as from ecological point of view. Based on the current researches it certainly looks like the main disadvantage of hydrogen as the clean fuel, namely the hydrogen production, is one obstacle that science should overcome in years to come.