Yes, solar power is renewable energy and clean, so is wind power and the energy that the hydroelectric power generators waste during the times of low demand. All these and many other energy sources can be used to break water down into hydrogen and oxygen. Hydrogen can be stored many different ways. Compressed hydrogen cylinders can be purchased from welding supply houses. Calcium hydrite has been used to store hydrogen for the purpose of filling balloons; all you need to do is add water to get lots of hydrogen. Palladium absorbs a lot of hydrogen and I think it can be released by heating.

I think that the combustion of Hydrogen/Oxygen mixtures should be studied further. It seem to me that the Hydrogen combustion is different from hydrocarbon combustion, in that pure Hydrogen/Oxygen mixture ‘burns’ into water. Water takes much less space than the combined H/O gas mixture, in other words ‘gas’ is turned into a liquid. Hydrocarbon mixtures on the other hand convert most of the liquid into a gas.

A regular combustion engine is not very efficient in converting hydrogen combustion into motive power, it was designed to burn hydrocarbon fuel, but design changes can be made to improve the efficiency. Fuel cells are a good way to convert hydrogen energy into electrical energy.

I definitely endorse the use of Hydrogen as an energy storage medium.

Cheers
Johannes