Green Hydrogen's Carbon Footprint May Exceed Brown Hydrogen

24 Feb 2024 CW Team

The report reveals a potential emissions scenario where green hydrogen, produced from 100% grid power, could carry a carbon footprint as high as 50 kilograms of CO2 equivalent per kilogram of hydrogen (kgCO2e/kgH2). This figure, surpassing the emissions associated with brown hydrogen, underscores the critical importance of ensuring electrolyzers run exclusively on renewable energy sources to maintain the environmental integrity of green hydrogen production.

According to the findings, approximately 30% of the 565 gigawatts (GW) of announced or operational green hydrogen projects could be at risk of contributing to this heightened carbon footprint if they connect to grids powered by non-renewable sources. This prospect poses a significant challenge to the global hydrogen market, which currently relies heavily on carbon-intensive grey or brown hydrogen, totaling around 90 million tons per annum.

The primary source of emissions in green hydrogen production stems from the electricity used by the electrolyzer. To mitigate these emissions and ensure the sustainability of green hydrogen, the report suggests a shift towards electrolyzers powered entirely by renewable energy.

However, the transition to renewable-powered electrolyzers faces hurdles, including the intermittent nature of renewable energy sources. Many projects opt to connect to the grid to maximize electrolyzer utilization and minimize costs. Yet, if access to renewable power is limited, these projects may inadvertently contribute to increased carbon emissions, highlighting the need for careful planning and investment in renewable infrastructure.

The report also underscores the importance of considering the full life-cycle emissions of hydrogen production and distribution. While carbon capture technologies offer promise in reducing emissions associated with blue hydrogen production, challenges remain in scaling these technologies and addressing emissions from other stages of the value chain, such as transportation and processing.

Regulatory compliance emerges as a critical consideration for hydrogen producers and consumers alike. Current standards, such as those set by the EU and Japan, focus primarily on production emissions, overlooking emissions from transport and processing. To meet evolving regulatory requirements, stakeholders must prioritize comprehensive life-cycle assessments and emissions reductions across all stages of hydrogen production and distribution.

Subsidies play a crucial role in supporting the transition to low-carbon hydrogen production. Incentive frameworks, such as those proposed by the European Commission and implemented by the UK government, aim to promote the use of renewable energy in hydrogen production and incentivize emissions reductions throughout the value chain.

Looking ahead, the future of green hydrogen hinges on strategic investments in renewable infrastructure, technological innovation, and regulatory frameworks that prioritize sustainability. As governments and industries around the world commit to decarbonization goals, the race to unlock the full potential of green hydrogen as a clean energy solution intensifies.

New research from Wood Mackenzie's Horizons report sheds light on a concerning trend in the burgeoning green hydrogen industry: despite its promise as a clean energy source, emissions from green hydrogen production could outstrip those of brown hydrogen, particularly if electrolyzers are connected to grids powered by fossil fuels.The report reveals a potential emissions scenario where green hydrogen, produced from 100% grid power, could carry a carbon footprint as high as 50 kilograms of CO2 equivalent per kilogram of hydrogen (kgCO2e/kgH2). This figure, surpassing the emissions associated with brown hydrogen, underscores the critical importance of ensuring electrolyzers run exclusively on renewable energy sources to maintain the environmental integrity of green hydrogen production.According to the findings, approximately 30% of the 565 gigawatts (GW) of announced or operational green hydrogen projects could be at risk of contributing to this heightened carbon footprint if they connect to grids powered by non-renewable sources. This prospect poses a significant challenge to the global hydrogen market, which currently relies heavily on carbon-intensive grey or brown hydrogen, totaling around 90 million tons per annum.The primary source of emissions in green hydrogen production stems from the electricity used by the electrolyzer. To mitigate these emissions and ensure the sustainability of green hydrogen, the report suggests a shift towards electrolyzers powered entirely by renewable energy.However, the transition to renewable-powered electrolyzers faces hurdles, including the intermittent nature of renewable energy sources. Many projects opt to connect to the grid to maximize electrolyzer utilization and minimize costs. Yet, if access to renewable power is limited, these projects may inadvertently contribute to increased carbon emissions, highlighting the need for careful planning and investment in renewable infrastructure.The report also underscores the importance of considering the full life-cycle emissions of hydrogen production and distribution. While carbon capture technologies offer promise in reducing emissions associated with blue hydrogen production, challenges remain in scaling these technologies and addressing emissions from other stages of the value chain, such as transportation and processing.Regulatory compliance emerges as a critical consideration for hydrogen producers and consumers alike. Current standards, such as those set by the EU and Japan, focus primarily on production emissions, overlooking emissions from transport and processing. To meet evolving regulatory requirements, stakeholders must prioritize comprehensive life-cycle assessments and emissions reductions across all stages of hydrogen production and distribution.Subsidies play a crucial role in supporting the transition to low-carbon hydrogen production. Incentive frameworks, such as those proposed by the European Commission and implemented by the UK government, aim to promote the use of renewable energy in hydrogen production and incentivize emissions reductions throughout the value chain.Looking ahead, the future of green hydrogen hinges on strategic investments in renewable infrastructure, technological innovation, and regulatory frameworks that prioritize sustainability. As governments and industries around the world commit to decarbonization goals, the race to unlock the full potential of green hydrogen as a clean energy solution intensifies.