Life cycle environmental impacts and costs of water electrolysis for green hydrogen

Life cycle environmental impacts and costs of water electrolysis for green hydrogen

As the world transitions towards a renewable energy-based future, hydrogen produced through water electrolysis powered by clean sources like wind and solar is emerging as a key enabler. The European Future Energy Forum is closely following Europe’s progress in deploying this promising technology. In this article, we explore the current and future environmental impacts and life cycle costs associated with different water electrolysis systems, providing crucial insights for realizing Europe’s green hydrogen ambitions.

Hydrogen Production Methods

Hydrogen can be produced through various routes, each with its own advantages and drawbacks. Traditionally, hydrogen has been generated primarily from fossil fuels, particularly via steam methane reforming (SMR) of natural gas. However, this process results in significant greenhouse gas (GHG) emissions. In contrast, water electrolysis – the process of splitting water into hydrogen and oxygen using electricity – offers a cleaner pathway, especially when powered by renewable energy sources.

The three most mature water electrolysis technologies are alkaline electrolysis cells (AECs), polymer electrolyte membrane electrolysis cells (PEMECs), and solid oxide electrolysis cells (SOECs). Each technology has its own unique characteristics, making a comparative assessment of their environmental and economic performances crucial for informing technology deployment decisions.

Renewable Energy Integration

A key aspect of water electrolysis for green hydrogen production is the seamless integration with renewable energy sources, such as wind and solar power. By coupling electrolyzers with these clean energy generators, the resulting hydrogen can be considered “green” – produced with minimal carbon footprint. This alignment with Europe’s decarbonization goals has driven significant research and investment in these hybrid energy systems.

Environmental Impacts of Water Electrolysis

To evaluate the sustainability of water electrolysis technologies, researchers have employed life cycle assessment (LCA) methodologies. These comprehensive analyses examine the environmental impacts across the entire value chain, from raw material extraction to hydrogen production and delivery.

Life Cycle Assessment Methodology

LCA studies on water electrolysis have considered a range of environmental impact categories, including global warming potential (GWP), ozone depletion, resource depletion, and water use, among others. The findings from these studies reveal that the choice of electricity source is a key determinant of the overall environmental performance, with renewable energy-powered electrolysis significantly outperforming grid-supplied electricity.

Greenhouse Gas Emissions

The GWP, measured in kg CO2-equivalent per kg of hydrogen, is a widely used indicator for assessing the climate change impact of hydrogen production. LCA studies have shown that in the near term (2022), the GWP of water electrolysis can range from 27.5 kg CO2-eq/kg H2 when using the current German electricity mix to as low as 1.33 kg CO2-eq/kg H2 when powered by renewable energy sources like wind. Further technological advancements and grid decarbonization are expected to drive these values down significantly by 2045.

Resource Depletion

In addition to GHG emissions, the consumption of critical raw materials, such as platinum, iridium, and rare earth elements, in the manufacturing of electrolysis system components is another important environmental consideration. LCA studies have highlighted the need to minimize the use of these scarce resources and explore material substitution strategies to enhance the long-term sustainability of water electrolysis technologies.

Economic Considerations

The economic viability of water electrolysis for green hydrogen production is a crucial factor in driving widespread adoption. Researchers have employed life cycle costing (LCC) methodologies to assess the levelized cost of hydrogen (LCOH) and other economic indicators.

Capital Costs

The capital expenditure (CapEx) associated with water electrolysis systems is a significant cost component. LCC analyses have shown that through technological advancements and economies of scale, the CapEx of AEC, PEMEC, and SOEC systems can be reduced by 34-80% by 2045, leading to substantial cost reductions.

Operating Costs

In addition to CapEx, the operating costs, including electricity, water, and maintenance expenses, also play a vital role in the overall LCOH. Optimizing these factors, particularly the electricity costs, can significantly improve the economic competitiveness of water electrolysis.

Cost Competitiveness

The latest LCC studies indicate that by 2045, the LCOH of water electrolysis-based hydrogen can range from €2.3/kg to €3.8/kg, depending on the technology and operational parameters. This aligns with the emerging hydrogen strategies and roadmaps in Europe, which aim to achieve cost parity with conventional hydrogen produced from fossil fuels.

Policy and Regulatory Frameworks

To support the widespread deployment of water electrolysis for green hydrogen production, various policy and regulatory frameworks have been established across Europe. These include hydrogen strategies, emission regulations, and financial incentives that create a favorable environment for investments and technological advancements.

The European Union’s Hydrogen Strategy outlines ambitious targets for installed electrolyzer capacity, aiming to reach 40 GW by 2030. This, coupled with carbon pricing mechanisms and renewable energy support schemes, is expected to drive further cost reductions and scale-up of water electrolysis technologies.

Moreover, the European Commission’s European Green Deal provides a comprehensive policy framework for achieving climate neutrality by 2050, underscoring the crucial role of clean hydrogen in the energy transition.

Conclusion

As Europe advances towards a sustainable energy future, the production of green hydrogen through water electrolysis is emerging as a pivotal technology. The comprehensive assessments of environmental impacts and life cycle costs presented in this article highlight the significant potential of this clean energy solution.

By leveraging renewable energy sources and driving technological innovations, the water electrolysis industry can achieve substantial reductions in greenhouse gas emissions and resource depletion, paving the way for a more sustainable and decarbonized energy landscape in Europe. The supportive policy frameworks and regulatory incentives will further catalyze the widespread adoption of this transformative technology, bringing us closer to a post-fossil fuel era.

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