Roughly 100 years ago, in February 1923, futurist John Haldane delivered a lecture at Cambridge University on wind farms that would provide England with clean and cheap electricity to produce hydrogen; he also envisioned the use of underground hydrogen storage to supply energy when the wind was not available (Haldane, 1923).
Since then, there have been several attempts (for example, during the oil crisis of the 1970s) to scale up hydrogen, particularly as a clean fuel to replace oil. Each occurrence of a “hydrogen wave of interest” marked a distinct phase in the exploration and development of hydrogen as a viable energy solution (see section 2).
The most recent phase is linked to international efforts to avert dangerous climate change. Countries around the world agreed in 2015 that rapid decarbonisation is needed and adopted the historic Paris Agreement. According to the Intergovernmental Panel on Climate Change (IPCC), human activities have unequivocally caused global warming, and in the last decade the average global surface temperature reached 1.1 degrees Celsius (°C) above pre-industrial levels. Based on the findings of Working Group III of the IPCC’s Sixth Assessment Report, global temperature is likely to exceed 1.5°C of pre-industrial levels this century, based on current global targets expressed in National Determined Contributions (NDC), and even limiting warming to below 2°C would rely on a rapid acceleration of mitigation efforts after 2030.
The global consensus now is that hydrogen and its derivatives – produced in ways that yield low life-cycle greenhouse gas emissions (i.e. “clean hydrogen”) – are part of the overall decarbonisation puzzle. They are a key solution to decarbonise hard-to-abate sectors, as well as for the large-scale, long-term storage and transport of clean energy. The role of clean hydrogen (see Box 2 for definitions) and its derivatives in industry to reach net-zero greenhouse gas emissions, and in mitigating emissions in the transport sector, were highlighted in the latest IPCC report on mitigation of climate change (IPCC, 2022).
At the 2023 United Nations Climate Change Conference (COP 28) in Dubai, United Arab Emirates, the Parties recognised for the first time the need for deep, rapid and sustained reductions in greenhouse gas emissions in line with 1.5°C pathways, and were called to accelerate the adoption of “low-carbon hydrogen” (UNFCCC, 2023). To set this route, many countries are actively developing national hydrogen strategic documents, with the objective of setting targets, informing the population and creating investor confidence (Box 1).
The 1.5°C Scenario developed by the International Renewable Energy Agency (IRENA), as set out in the Agency’s World Energy Transitions Outlook, also highlights the important role of hydrogen. The scenario describes an energy transition pathway aligned with the ambition to limit the increase in the global average temperature by the end of this century to 1.5°C, relative to pre-industrial levels. It prioritises readily available technology solutions, which can be scaled up at the necessary pace to achieve the 1.5°C goal.
In the 1.5°C Scenario, clean hydrogen and its derivatives account for 12% of the overall reduction in carbon dioxide (CO2 ) emissions by 2050 (Figure 1). Reaching this share will require enormous efforts, with clean hydrogen production increasing from 0.7 million tonnes in 2022 to 523 million tonnes annually by 2050. The share of green hydrogen in clean hydrogen is expected to be 94% in 2050. Investment needs for clean hydrogen infrastructure – including electrolysers, infrastructure, fuelling stations, bunkering facilities and long-term storage – will need to increase from USD 1.1 billion in 2022 to USD 170 billion annually by 2050. The cumulative installed capacity of electrolysers would increase from 550 megawatts (MW) in 2020 to 5.7 terawatts (TW) by 2050 (IRENA, 2023a).
