Hydrogen (H2) was identified as a potential solution to have a clean fuel in the future. Hydrogen has characteristics that give it Properties to be a renewable element capable of providing safe energy, economically competitive and free of carbon dioxide (CO2) emissions. In this work we study how to obtain energy from hydrogen. To do this, the combustion of hydrogen is analyzed, which can be done through two methods: directly, through a chemical process with heat production; and by an electrochemical process in which the chemical energy of hydrogen is transformed directly into electricity. Keywords:hydrogen, energy, combustion.