Over the past two years we have brought you a growing blog series looking at the various aspects of hydrogen and what the future use may be. Below is a look back at the series:

• Interest in hydrogen and ‘hydrogen-carrying gases’ continues to grow – “here is our latest round-up of project announcements all pointing in the same direction – to a greater use of hydrogen and ammonia as both fuels and energy vectors in a wide range of applications from home-heating to power generation to industrial uses to transport.”
• Can hydrogen compete in costs terms? – “Hydrogen ‘ticks a lot of boxes’ for being a widespread energy vector or fuel for the future. Most importantly, it can be made in a low- or zero-carbon way, but it also stores energy in a dense manner, and might be retrofitted to existing infrastructure and industry originally intended for natural gas use.”
• Full steam ahead to a hydrogen future! – “London’s iconic red double-decker buses are going green!  In May, Transport for London (TfL) announced that it will be introducing the world’s first hydrogen double-decker buses on three bus routes in London next year as part of its drive to make London’s transport zero-emission.”
• Hydrogen and combustion: big challenge, big chance – “For the combustion community, the challenge translates into a timely, potentially huge opportunity.  A flourishing, mutually beneficial long-term relationship between hydrogen energy and combustion technologies has real scope to develop.  More specifically, combustion can play a massive part in enabling hydrogen to emerge as a compelling energy option – giving combustion a welcome chance, in turn, to reinvent and reposition itself as a green technology with a very bright future.”
• Select-a-vector: will hydrogen win the race? – “But it is imperative to recognise that – despite hydrogen’s decarbonising potential – technical, cost and perception barriers remain.  Nor is the quest to identify a dominant new vector a one-horse race.  So what rival options are there – and can hydrogen beat them to the finishing line?  Prepare for a glimpse of some mind-bending parallel energy futures…”
• Hydrogen: the heart of the matter – “For hydrogen energy, the issue of image goes to the heart of its future prospects.  But in a world where the word of experts seems increasingly distrusted and sometimes derided – and where ‘alternative facts’ gain alarming traction – can hydrogen’s perception problem be tackled?  If so, how?”
• Hydrogen: so what’s the use? – “This striking story was a timely reminder of hydrogen’s huge potential as a highly versatile energy carrier that could touch virtually every aspect of our lives.  It underlined the fact that – albeit usually well away from the glare of publicity – hydrogen is gradually emerging as a real-world energy option for a whole range of uses.”
• Hydrogen: the great game-changer? – “Revolution or evolution?  However you define current and prospective developments in the global energy sector, surely this much is certain: the sector has begun to experience an irreversible, far-reaching transformation.”
• Hydrogen: securing supplies for a colourful future – “one key question is this: where is the hydrogen going to come from?  Let’s call it the hydrogen paradox.  It may be the simplest, most plentiful element in the universe, but there are no natural, pure supplies here on Earth.  If we want more of it, we’ll have to make it.”