Hydrogen stove boiling a pan of water in a self- sufficient solar powered house. The house produces hydrogen and oxygen, using electricity from solar panels to split water by electrolysis. The hydrogen is used for cooking. It burns without a visible flame. During periods with little sun, the gases can be recombined in a fuel cell to generate electricity. This allows excess energy from sunny periods to be stored until it is needed. This demonstration house in Freiburg, Germany was completed in 1992.