
technology is the continues production of electricity which as we know is conditional on the presence of sunlight. So storing some of this excess energy when produced is absolutely necessary to maintain its prefer-ability.
Scientists are researching the best scenarios to use hydrogen to store this excess energy. This is because hydrogen gas stores chemical energy. The theory is to use the solar energy to electronically split water molecules into hydrogen and oxygen by using two electrodes that are coated with suitable catalysts and between which a minimum 1.23 volt tension is generated. This produced hydrogen is then used as a storage fuel.

This innovative research is important because 'on sunny days, excess electricity could yield hydrogen, which would be available for fuel or to generate electricity at a later point like at night or on days that are overcast' (ref).
Original article: phys dot org
Images: top - science for kids, bottom - conservation magazine