New Research Challenges the CO₂ Benefits of Green Hydrogen
A study from the Technical University of Eindhoven reveals that the anticipated CO₂ reductions from green hydrogen production and transport may not always be realized due to lifecycle emissions.
Lifecycle Emissions of Green Hydrogen
Kiane de Kleijne’s research at the Technical University of Eindhoven has brought to light the hidden emissions associated with green hydrogen production and transport. The study, published in Nature Energy on June 21, 2024, provides a comprehensive analysis of the lifecycle greenhouse gas emissions involved in green hydrogen, countering the perception that it is a completely emission-free energy solution. By examining the full lifecycle emissions, including those from manufacturing solar panels and electrolyzers, the research highlights areas that have been previously overlooked in emission calculations.
The Role of Renewable Energy in Green Hydrogen Production
Green hydrogen production involves the process of electrolysis, where water is split into oxygen and hydrogen using electricity generated from renewable sources. While this method is touted for its potential to significantly reduce CO₂ emissions compared to hydrogen produced from natural gas, de Kleijne’s research underscores the importance of the type of renewable energy used. The study indicates that using wind power for electrolysis results in greater CO₂ reductions than solar power due to the higher energy efficiency of wind turbines. However, substantial amounts of renewable energy are needed to achieve these reductions, which can be a limiting factor.
Impact of Transportation on Emissions
One of the critical findings of the study is the significant emissions associated with transporting green hydrogen over long distances. The data reveals that much of the CO₂ gains from producing hydrogen in locations with abundant renewable energy are negated when the hydrogen is transported to distant markets. For example, transporting hydrogen via pipeline or shipping adds approximately 1.5 to 1.8 kilograms of CO₂ equivalents per kilogram of hydrogen, respectively. This highlights the need for localized production to maximize the environmental benefits of green hydrogen.
Current Calculation Methods and Overlooked Emissions
The research critiques current calculation methods for green hydrogen emissions, which often exclude the emissions from the production of renewable energy infrastructure and hydrogen leakage during transport. By including these factors in the lifecycle analysis, de Kleijne’s study provides a more accurate picture of the true environmental impact of green hydrogen. This comprehensive approach reveals that even in the most optimistic scenarios, the median emissions from green hydrogen production are around 2.9 kilograms of CO₂ equivalents per kilogram of hydrogen.
Moving Forward with Improved Technologies
To truly harness the potential of green hydrogen as a low-emission energy source, the study suggests focusing on improving production and transport technologies. Innovations in electrolyzer efficiency, renewable energy generation, and hydrogen transport methods are crucial. Additionally, regulatory frameworks need to be updated to include lifecycle emissions in their assessments, guiding more informed decisions in the hydrogen supply chain. As the global push for green hydrogen continues, such insights will be vital in ensuring that this promising technology can effectively contribute to reducing greenhouse gas emissions.