Unpacking the carbon intensity of hydrogen
In fall of 2020, hydrogen was big news—and it still is. In advance of the Government of Canada’s launch of a national hydrogen strategy, we released a report titled A New Hope, exploring Canada’s hydrogen opportunity and the potential it holds as a climate solution and for our economy. The report showcased a number of key findings.
Hydrogen has several unique advantages as a climate solution, particularly in sectors that are the most difficult to decarbonize, often referred to as the “toughest third” of emissions. These include trucking, shipping, and the production of steel, fertilizer, and cement. However, hydrogen only works as a climate solution if its production is cleaned up.
As the world drives to a net-zero future (with 127 countries—including the U.S and Canada—representing 63% of the world’s emissions having adopted or considering net-zero targets), cost and cleanliness will dictate which nations’ hydrogen sectors are best positioned to compete in the years to come.
According to research out of Harvard, Canada is among a small group of countries with the highest potential for exporting clean hydrogen, thanks to a clean power system (83% of Canada’s electricity grid is already non-emitting) and plenty of access to water (required for electrolysis for the production of green hydrogen).
BloombergNEF estimates that clean hydrogen could meet up to a quarter of the world’s energy demand by 2050. To succeed in this global market, Canada must harness its competitive advantages and plan to produce, use, and export the world’s cleanest hydrogen and its related technologies.
While our findings haven’t changed, what has changed is the available research on the emissions intensity of various forms of hydrogen production—and they’re worth a read.
New research on blue hydrogen (produced from natural gas with carbon capture and storage), published by scientists at Cornell and Stanford, finds that its carbon intensity may be higher than previously thought. Other analyses, such as this one conducted by Zen for the Government of British Columbia, previously assessed the carbon intensity of blue and other forms of hydrogen, but the degree of transparency in this latest study helps drive a more robust debate about the assumptions involved in accounting for these emissions.
The carbon intensity of blue hydrogen depends on several factors. Among others, these include the extent of upstream methane leakage, emissions from driving the steam methane reforming and carbon capture processes, the rate at which carbon emissions are captured, and the degree of permanence when storing the captured carbon.
The resulting carbon intensity can be presented based on the global warming potential of greenhouse gases over specific timeframes. A perspective of 20 years amplifies the near-term warming impact of methane, which has a shorter lifetime compared to carbon dioxide, while a 100-year perspective considers the climate impacts over a longer period.
Based on a set of assumptions for these factors and a global warming potential over 20 years, the new study finds that the carbon intensity of blue hydrogen is only 9-12% smaller than that of grey hydrogen. (Grey hydrogen is also produced from natural gas but does not employ carbon capture and storage and is therefore not considered a climate solution.) When applying a global warming potential of 100 years, the authors find an emissions reduction of 19-27% compared to grey hydrogen.
The latest research also demonstrates that clean electricity can substantially reduce the carbon intensity of blue hydrogen. Using zero-emissions electricity during the production of blue hydrogen—to power the steam methane reforming and carbon capture processes—can reduce emissions by 66% compared to grey hydrogen. This finding is based on a 20-year period, with an even larger reduction expected using a 100-year timeframe.
However, the world’s cleanest hydrogen—whether that is green hydrogen made from renewable electricity and water using a process called electrolysis or via other, innovative forms of zero-emissions hydrogen—must be Canada’s long-term goal. While green hydrogen is still more costly to produce today than blue hydrogen, BloombergNEF and the International Renewable Energy Agency project the cost of producing green hydrogen to be on par with blue hydrogen by 2030, and lower thereafter. What’s more, international attention—from Germany to Australia to Oman—on producing green hydrogen may spur cost declines even sooner.
This new study is a timely reminder that transparency and rigour in accounting for the life-cycle emissions of all hydrogen pathways is essential. It also highlights the importance of addressing upstream methane emissions, and it provides yet another example for why further decarbonization of the electricity sector is crucial across all of Canada.
For Canada to succeed, we need government policy to support the cleanest hydrogen pathways with the most advanced technologies to achieve the highest emissions reductions possible. These need to be supported with strong legal and regulatory frameworks along with robust leak detection technologies to ensure the permanence of carbon storage. If Canada wants to compete globally, there’s simply no other option.