2 H2O(l) → 2 H2(g) + O2(g)
In the world of fossil fuel, the fuel is the storage medium. Coal, gas and oil can can be conveniently stored until they are needed. With solar and wind that option doesn’t exist. There can be a large mismatch between supply and demand that needs to be bridged. One of the storage options is hydrogen that can be won from electrolysis of water on the very moment that renewable electricity is produced.
The idea of using hydrogen as the central storage facility originates from 1970, when the term ‘hydrogen economy’ was minted. The advantages are clear: high energy density per unit of weight and clean burning with only water coming from the exhaust. The disadvantages are explosiveness and extremely low temperatures required to liquefy hydrogen in order to achieve high energy density per unit of volume as well. Hydrogen can be used to burn like gasoline and converted into mechanical energy or transformed chemically in a fuel cell to produce electricity. In both cases hydrogen is combined with oxygen to produce water.
As with any conversion technology, the aim is to minimize energy losses and achieve high efficiency. In this post you will find videos that highlight the electrolysis process.
[wikipedia.org] – Electrolysis of water
[wikipedia.org] – Fuel cell
[wikipedia.org] – Hydrogen economy
[amazon.com] – Jeremy Rifkind, The Hydrogen Economy
[theguardian.com] – What’s the ‘hydrogen economy’?
[siemens.com] – SILYZER 200 (PEM electrolysis system)
[profadvanwijk.com] – The Green Hydrogen Economy in the Northern Netherlands