How can-hydrogen be used to produce electricity?

I think bio-energy is not at all safe for us. Besides, it is causing environmental disasters, crop failure, soil and river erosion and other havocs. Moreover, excessive use of bio-energy paves the way for deforestation and all other deadly forms of climate.

Hydrogen in combination with oxygen makes water.

Geothermal energy is the thermal energy in the earth's crust which originates from the formation of the planet and from radioactive decay of materials in currently uncertain but possibly equal proportions.

Plants need sunlight, rain and snow to grow.