What’s the hype about hydrogen?

By Mariusz Bogacki, Researcher and Science Communicator, Edinburgh

It is potentially the future of fuel – as long as we find a way to produce it using renewable energy sources.

Hydrogen is one of the most abundant elements in the universe. It is essential for life, and the sun is mostly made of it. On Earth, it can be found mainly when combined with oxygen in the form of water. Scientists have long been working on ways to turn this plentiful element into feasible fuel source.

Hydrogen acts as a chemical energy carrier, just like oil or gas, that can be transported to where it is needed. It stores three times as much energy per unit of mass as conventional petrol, and when it ‘burns’ in air – releasing that stored energy – it simply combines with oxygen to produce water again.

Today, hydrogen fuel can be produced through several methods. The most common ones are through thermal process, and electrolysis.

Thermal processes for hydrogen production typically involve steam reforming, a high-temperature process in which steam reacts with a hydrocarbon fuel to produce hydrogen. Electrolytic processes involve separating water into oxygen and hydrogen. Electrolytic processes take place in an electrolyser, which functions much like a fuel cell in reverse. Instead of using the energy of a hydrogen molecule, like a fuel cell does, an electrolyser creates hydrogen from water molecules.

The problem is that both of these production processes are energy intensive and fuelled largely by using fossil fuels or lots of electricity. This has always made hydrogen both expensive and less efficient than other ways of storing and delivering energy. Since we have realised the dangers of climate change, hydrogen energy hasn’t been deemed worth it. The only way to make hydrogen a truly green source of energy is to produce it using clean energy.

However, with the recent developments in renewable energy production (see our reporting on bladeless wind turbines, Perovskite Crystal solar panels and unusual sources of biofuel) and ever greater governmental support for it, hydrogen production is once again being considered as a feasible source of fuel.

There are many possible applications of hydrogen fuel, most of which relating to transport and heavy industries, such as steel and cement-making. This year alone, many companies, including BP and Mitsubishi Power, have said that they will be investing in hydrogen fuel solutions. Flights corporations such as Airbus are also working on zero-emission commercial aircrafts running on hydrogen, with hopes to have them flying by 2035. According to a report from The Economist magazine, the projected total investment in the hydrogen sector amounts to an estimated $500 billion.

Such serious investments by a major international corporation and governments will surely put the ‘hype’ about hydrogen to a test. Let’s hope the results will be as clean as the water produced by this abundant fuel source.