The global energy demand is expected to grow significatively in the next decades, driven by economic and population growth.1However, our current energy sector is heavily reliant on fossil-base energy carriers, such as coal, oil and natural gas.
The indiscriminate use of these resources, with consequent emission of green house gases (GHG), is the primary cause for the alarming increase in world’s temperature. In 2021, energy-related carbon dioxide (CO2 – one of the main GHG) emissions reached 36.3 billion tons (6% of the total CO2 emissions), setting a new record, the highest ever.2
In response to this threat of climate change, the Paris Agreement set the goal of limiting the global warming to 2 degrees above the pre-industrial level. A key player in this energy transition is green hydrogen. In fact, a renewed interest in hydrogen, already under the radar as potential alternative energy carrier many years, has surged in the last five years to meet the Paris Agreement. The production of green hydrogen from water electrolysis might also represent a more accessible energy carrier, contrary to a fossil-fuel-based society where inequal distribution of resources and geopolitical instability repeatedly threaten the worldwide stability of the current energy system.
As such, the European Union (EU) has recently set ambitious goals for the next decades aiming to increase the current yearly hydrogen production of about 100 MW, to 40 GW ( ̴ 10 million tons) in 2030.3
Green hydrogen production technologies are currently available at different level of maturity. Alkaline electrolysers (TRL – technology readiness level – 9) and polymer electrolyte membrane electrolysers (TRL 8), and represent the most promising technology to be used on a large scale in the coming years.4 Other promising technologies are solid oxide electrolysis (TRL 6), natural gas reforming with CO2 capture (TRL 8), biomethane reforming with CO2 capture (TRL 8), low temperature biomass gasification (TRL 7) and high temperature biomass gasification (TRL 6).4 The reported costs for these technologies are presented in Figure 1. Other alternative hydrogen production technologies are also being developed.5,6
Even we have several technologies which we could be using nowadays as seen in Figure 1, the technological cost needs and related challenges prevent its implementation. For example, the use of alkaline and polymer electrolysis is challenged by the availability of low carbon electricity and as well as its high costs while the implementation of natural gas or biomethane reforming with CO2 capture is challenged by the fugitive methane emissions from the natural gas supply, and the availability of a CO2 transport and storage infrastructure.7,8
Hydrogen has been for long time considered as a promising future green energy carrier, but technological and socio-economical barriers did not allow the H2 economy to be deployed at large scale. Will the next decades be finally the years in which we will witness a full take off of green hydrogen technologies supporting the transition towards a carbon neutral energy system?
We really hope so…
Recent news of interest:
- European Commission’s Clean Hydrogen Partnership (CHP) has launched a call of proposals offering €300.5m of grants “to support projects that boost renewable hydrogen production, reduce its costs, develop its storage and distribution solutions, and stimulate the use of low carbon hydrogen in hard to abate sectors, such as energy intensive industries, aviation or heavy duty transport”.: Source: https://www.clean-hydrogen.europa.eu/apply-funding/call-proposals-2022/call-proposals-2022_en
- In the Netherlands, the growth fund programe GroenvermogenNL announced that they will receive extra €500m adding to the existing €338m to: “accelerate the production and use of green hydrogen and related technology in various industrial chains, such as chemistry, kerosene, steel or fertilizer”
1. IRENA, Global Energy Transformation: A roadmap to 2050, International Renewable Energy Agency, 2018, Abu Dhabi.
2. International Energu Agency (IEA) 2021: “https://www.iea.org/news/global-co2-emissions-rebounded-to-their-highest-level-in-history-in-2021”
3.European-Commission, A hydrogen strategy for a climate-neutral Europe. COM(2020) 2020, 301 final.
4.Van der Spek, M.; Banet, C.; Bauer, C.; Gabrielli, P.; Goldthorpe, W.; Mazzotti, M.; Munkejord, S. T.; Røkke, N. A.; Shah, N.; Sunny, N.; Sutter, D.; Trusler, J. M.; Gazzani, M., Perspective on the hydrogen economy as a pathway to reach net-zero CO2 emissions in Europe. Energy & Environmental Science 2022, 15 (3), 1034-1077.
5.Rioja-Cabanillas, A.; Valdesueiro, D.; Fernández-Ibáñez, P.; Byrne, J. A., Hydrogen from wastewater by photocatalytic and photoelectrochemical treatment. Journal of Physics: Energy 2020, 3 (1), 012006.
6.Sazali, N., Emerging technologies by hydrogen: A review. International Journal of Hydrogen Energy 2020, 45 (38), 18753-18771.
7.Parkinson, B.; Balcombe, P.; Speirs, J. F.; Hawkes, A. D.; Hellgardt, K., Levelized cost of CO2 mitigation from hydrogen production routes. Energy & Environmental Science 2019, 12 (1), 19-40.
8. Lane, J., Greig, C. & Garnett, A. Uncertain storage prospects create a conundrum for carbon capture and storage ambitions. Nat. Clim. Chang. 2021 11, 925–936.