According to Future Cars, advantages of hydrogen fuel cells include non-corrosion, water vapor emissions and an indefinite fuel source. One disadvantage is the excessive carbon dioxide emissions when making hydrogen fuel cells; another is the fact that replacing fossil fuel infrastructure with fuel cells requires a massive investment in the billions or trillions of dollars.
In regards to advantages, Alternative Energy notes that hydrogen fuel is converted to electricity in a more efficient manner than other forms of technology. Furthermore, fuel cells are flexible and can be installed easily. It can also be a great asset in reducing reliance on foreign power sources. Pure hydrogen is pollution-free when generating heat, electricity or water. Also, fuel cells are compact and smaller in scale, while generating a larger degree of efficient energy than large power plants.
When it comes to disadvantages, fuel cells are generally expensive to manufacture. Alternative Energy mentions the cost of fuel cells is dropping, but expense is still the primary drawback. There is also little to no technological infrastructure to fuel hydrogen-based cars around the country properly. The most notable problem is the flammability factor. Many people think of the Hindenburg upon mention of hydrogen fuel cells. Another main problem is the rarity of hydrogen itself in Earth's atmosphere, although it is abundant throughout the universe. Hydrogen must be extracted by way of electrolysis, which is often unpredictable and costly.