Researchers at the Paul Scherrer Institute PSI have explored the most cost-effective global regions for hydrogen production. This is a step towards establishing an economy that relies on this clean energy source rather than fossil fuels. Their findings highlight that switching to electricity and hydrogen won’t eliminate greenhouse gas emissions. This research is detailed in a publication released in Nature Communications today.
Switzerland’s goal to achieve climate neutrality by 2050 dictates that starting this year, no additional greenhouse gases should be emitted, aiming to mitigate climate change effects. A significant strategy towards this end involves electrifying transportation, industry, and households and transitioning to renewable energy sources like hydro, wind, and solar power. However, not all energy needs can be met through electricity due to its limited storage capacity for certain applications. Here, hydrogen emerges as a beacon of hope, expected to play a crucial role in significantly lowering climate impacts in sectors such as aviation, agriculture, and steel manufacturing and could be further processed into products like fertiliser and synthetic hydrocarbons.
The team, led by Tom Terlouw and Christian Bauer of PSI’s Laboratory for Energy Systems Analysis, gathered geographical and economic data to model the growth of a hydrogen economy under four scenarios. Their projections suggest hydrogen demand could range from 111 to 614 megatonnes annually by 2050, depending on the scenario. Currently, global production is about 90 megatonnes per year.
A vital aspect of the study focused on identifying ideal locations for hydrogen production via electrolysis. The current dominant method of hydrogen production involves steam methane reforming from fossil fuels under high pressure and temperature. More optimistic future scenarios, however, predict a shift towards PEM electrolysers that use electricity and a polymer electrolyte membrane to split water into hydrogen and oxygen. Using renewable energy for this process could dramatically reduce greenhouse gas emissions by up to 90% compared to the traditional method.
The study primarily evaluated economic factors to determine the most cost-effective production locations, considering the availability of renewable energy and land for building necessary facilities. Canada emerged as an ideal region due to its abundant wind and water resources and stable political climate, making it suitable for large-scale hydrogen production. In contrast, Switzerland and other central European countries face limitations due to scarce land for wind turbines and lower solar radiation levels. However, the potential of other regions like the central United States, parts of Australia, the Sahara, northern China, and northwestern Europe, with their renewable energy capabilities and available space, offers a promising outlook for the future of energy production.
Despite these optimistic projections, the study also addressed the ecological drawbacks of a hydrogen-based economy. Residual greenhouse gas emissions will remain challenging, with estimates suggesting nearly one gigatonne of CO2 equivalents annually. Production and distribution of hydrogen contribute to these emissions, including leaks that release hydrogen into the atmosphere, indirectly increasing levels of other potent greenhouse gases like methane and ozone.
The study further discussed the environmental impact of materials used in hydrogen production, such as the rare earth metals in wind turbine magnets and iridium in PEM electrolysis catalysts. The demand for immense land and water resources for hydrogen production poses additional environmental concerns.
The study emphasised the importance of social acceptance for large-scale hydrogen production facilities, particularly in areas where water is scarce and desalination may be required. While this study lays the groundwork for understanding potential strategies for energy transition, further research is needed to evaluate these factors comprehensively. The researchers highlight possible paths for achieving the energy transition, acknowledging that the extent and rigour of these efforts depend on socio-political decisions.
More information: Tom Terlouw et al, Future hydrogen economies imply environmental trade-offs and a supply-demand mismatch, Nature Communications. DOI: 10.1038/s41467-024-51251-7
Journal information: Nature Communications Provided by Paul Scherrer Institute