Solar fuel cells

In the video above, Prof. Maria Forsyth discusses whether storing energy in solar fuels is as good as using batteries. If we could make fuels like H₂ from only sunshine and water, how sustainable would that be?

Plants split water into H⁺ and O₂ using natural catalysts that are renewed every 30 minutes. We can already do the same thing very easily using electricity and metal electrodes in a process called electrolysis (water splitting) but this is very expensive in both energy and materials cost. To store solar energy in a H₂ fuel on a large scale to meet the Terawatt challenge, we need to be able to split water with renewable energy or a solar driven process using inexpensive materials. This is indeed what a number of researchers, startup and established companies around the world are currently working hard to achieve.

Yet, if H₂ is a fuel that’s storing energy, how do we get the energy back out?

That’s easy using fuel cells that produce electricity by doing exactly the opposite of splitting water – reacting H₂ and O₂ to form water again as in the animation below that shows the operation of one cell in a fuel cell stack. So fuel cells run by consuming hydrogen, a ‘zero-emission’ fuel and produce only water and electricity.

_{A larger image can be found on the bottom of this page (Fuel cell technology)}