Hydrogen's role in a net zero world

Depending on who you listen to, hydrogen is the answer to the question of a sustainable future. Yet, as is often the case with such major questions, the issues around hydrogen are not simple. Here we dig into the evidence to discover the role that hydrogen has to play in facing the greatest challenge of a generation.

- MARTIN OLIVER

Hydrogen is the most abundant element in the universe, estimated to make up 75 per cent of all matter. With an atomic number of one, it is a colourless and odourless gas that is highly flammable. On Earth, it only exists when combined with other elements, notably as water (H2O), with two molecules of hydrogen-bonded to one of oxygen.

According to the hype, hydrogen is going to be a central element of a future sustainable world. As countries and corporations race to slash their emissions, many new announcements in the hydrogen field are being made, and the picture is continuously updating. However, when examined closely the advantages of hydrogen are not so straightforward. An important issue is the sequence of energy inefficiencies and losses that are necessary before hydrogen can be burned as a fuel.

Interestingly, most of today’s hydrogen production is as a feedstock for industrial processes, often in oil refining, to make ammonia for fertilizer manufacture and to produce methanol. A small but growing proportion is being produced for use as an energy source.

Fossil fuel versus renewable

Today, hydrogen can be made from gas, coal, oil, renewables or nuclear. It is bound up with energy politics, and the pivotal issue of whether fossil fuels can have a future in a net-zero emissions world. This involves blue hydrogen, a name for combining fossil fuel-produced hydrogen with carbon capture and storage (CCS) to bury CO2 emissions underground. Hydrogen could offer the fossil fuel sector a lifeline into the future, where it can disguise the dirty origin of what sounds like a clean product.