Climate change and innovation

Hydrogen’s moment is here at last. After decades of doubts the gas is coming of age.
Hydrogen has been controversial ever since the tragedy of the Hindenburg, an airship filled with it that went down in flames in 1937. Boosters say that the gas is a low-carbon miracle which can power cars and homes. The hydrogen economy, they hope, will redraw the energy map. Sceptics note that several hydrogen investment drives since the 1970s have ended in tears as the gas’s shortcomings were exposed. As we explain, the reality lies in between. Hydrogen technologies could eliminate perhaps a tenth of today’s greenhouse-gas emissions by 2050. That is a sliver—but, considering the scale of the energy transition, a crucial and lucrative one.

Hydrogen is not a primary source of energy like oil or coal. It is best thought of as an energy carrier, akin to electricity, and as a means of storage, like a battery. It has to be manufactured. Low-carbon energy sources such as renewables and nuclear power can be used to separate water (H2O) into its constituents of oxygen and hydrogen. This is inefficient and expensive, but costs are falling. Hydrogen can also be made from dirty fossil fuels but this emits a lot of pollution unless it is coupled with technologies that capture carbon and sequester it. Hydrogen is flammable and bulky compared with many fuels. The implacable laws of thermodynamics mean that converting primary energy into hydrogen and then hydrogen into usable power leads to waste.

hydrogen economy

Creating the new hydrogen economy is a massive undertaking.It is also a delicate one.

Today’s hydrogen business is, in global terms, reasonably small, very dirty and completely vital. Some 90m tonnes of the stuff are produced each year, providing revenues of over $150bn—approaching those of ExxonMobil, an oil and gas company. This is done almost entirely by burning fossil fuels with air and steam—a process which uses up 6% of the world’s natural gas and 2% of its coal and emits more than 800m tonnes of carbon dioxide, putting the industry’s emissions on the same level as those of Germany.

The vital nature of this comes from one of the subsequent uses of the gas. As well as being used to process oil in refineries and to produce methanol for use in plastics, hydrogen is also, crucially, used for the production of almost all the world’s industrial ammonia. Ammonia is the main ingredient in the artificial fertilisers which account for a significant part of the world’s crop yields. Without it, agricultural productivity would plummet and hundreds of millions would face starvation.