why is hydrogen not used as fuel though it has highest calorific value?

because of its less availability and high price.

Hydrogen is not used as a domestic fuel even though it has the highest calorific value due to the following points -

• It is'nt cheap and easily available
• It is not easy to store
• It is highly explosive
• It does not burn at a slow rate with controlled combustion
• It is not safe to handle