Life cycle assessment of hydrogen production by PEM electrolyzer technology based on solar and wind energy sources in Portugal

11/27/2024

The effects of climate change have increased the awareness of sustainability, prompting countries and organizations to reduce fossil fuel use and invest in renewable energy and hydrogen production. As this energy transition accelerates, green hydrogen production through Proton Exchange Membrane (PEM) electrolysis powered by renewable energy appears to be a promising solution. This study conducts an attributional life cycle assessment of a 44 MW PEM electrolysis plant in Portugal, powered by solar and wind energy. While green hydrogen is sustainable, it is crucial to assess its production environmental footprint, as there are associated emissions. The system boundary is cradle to-grave, focusing solely on the production stage of hydrogen, using SimaPro software and the ReCiPe 2016 midpoint model for simulation analysis. A sensitivity analysis is conducted to evaluate the electricity source, electrolyzer lifetime, and electrolyzer efficiency. The global warming potential was found to be 2.51 kg CO2-eq/kg H2. Results show that the operation phase had the highest environmental impacts across the life cycle, mainly due to the renewable sources. In the construction phase of the electrolyzer system, transition metals contributed most significantly to the impacts, emphasizing the need for sustainable alternatives. The sensitivity analyses of the electricity source show an increase in emissions to 7.89 kg CO2-eq/kg H2 when the Portuguese grid mix is used. Increasing electrolyzer efficiency by 7.3% reduced GWP by 0.24 kg CO2-eq/kg H2, while extending the electrolyzer’s lifetime from 10 to 17.5 years resulted in slight reductions in total impacts, with notable reductions in the construction phase.

Authors in the community:

• 

  F

  Francisco Leão Duque Simões

  ist196379

Supervisors of this institution:

• 

  R

  Rui Pedro da Costa Neto (Rui Costa Neto)

  ist90104

• 

  W

  Wagd Ajeeb

  ist428791

mechanical-engineering - Mechanical engineering

por - Portuguese

Instituto Superior Técnico