Hydrogen can be created by water. if the activation energy is reduced, hydrogen can be produced with a renewable energy source. this renewable energy source is

The given blanks can be filled with decomposing and solar energy.

Explanation:

The formation of hydrogen can take place by the decomposition of water. The passing of electricity from the water and attaining the components like oxygen and hydrogen due to the decomposition of water is known as electrolysis.  

With the reduction of activation energy, hydrogen can be generated with a renewable energy source. This renewable source of energy is solar energy. The solar energy can be utilized to reduce the activation energy at the time of decomposition of water. The solar energy can be gathered and used for the generation of hydrogen.