Hydrogen Power, Pros & Cons
Hydrogen fuel cells are highly efficient and less dangerous than gasoline
Hydrogen is the cleanest energy source we know of. In a electric fuel cell electricity is created by combining hydrogen and oxygen.
Without combustion, the only byproducts are water and heath.
Although hydrogen can be produced from diverse renewable resources already, the main challenge is cost. Most of the cost of creating hydrogen by electrolysis, comes from buying power from the grid. So new research is good for the future of affordable hydrogen. Read More
Geothermal energy is generally considered environmentally friendly. There are a few polluting aspects of harnessing geothermal energy, but these are minor compared to the pollution associated with conventional fuel sources (e.g. coal, fossil fuels). 
