Is the future powered by hydrogen?
New research on the climate impact of hydrogen
Hydrogen as an alternative fuel has long been a topic of discussion. Now, a new research project has examined hydrogen leaks—and their potential consequences for the climate.
"So far, there has been little research on the climate impact of hydrogen leakages. Notably, it has not been quantified by the IPCC," says CICERO researcher Maria Sand.
She is leading a large project on hydrogen. Together with research colleagues, she has conducted an international study, where they used several global models to estimate the climate impact of hydrogen leakages.
"This was a critical need in the hydrogen industry, which was hesitant to implement measures due to significant uncertainty around the effects of leakages on the environment," says Sand.
The study concluded that the global warming potential for hydrogen is 12, which means that 1 kg of hydrogen leakage has a 12 times greater warming effect on the atmosphere than 1 kg of CO₂ emissions. GWP is a measure for comparing the emissions of different gases.
Systematic measurement of leakages
In the research project, user partners such as Equinor and Statkraft have been involved. Based on the findings regarding the climate impact of hydrogen, they have modified their procedures to measure hydrogen emissions in their operations.
"They are now measuring leaks across the entire value chain, that is to say everything from production to pipelines, storage, and use. There are leaks leaks at every stage. The instruments used for such measurements until now have mainly been related to safety and the detection of larger hydrogen leaks. The same instruments do not have the ability to measure small leaks, and therefore the industry must develop new types of leak detection technology," says Sand.
"Production is costly, so it is not cost-effective if it turns out that there is a high rate of leakage. A first step is, of course, to know how large these emissions are," says Sand.
When it comes to the application areas for hydrogen, she believes it can be a solution in sectors that are difficult to decarbonize.
"In the steel industry, for example, hydrogen can replace coal, and it may also be relevant in heavy-duty transport and shipping, where there is great interest in the use of hydrogen and other cleaner fuels," she says.
Today, there are several ferries powered by batteries, but for longer journeys, hydrogen can play an important role.
"However, for the longest routes, liquid ammonia or methanol are more relevant, as they are more energy-dense, meaning they can store more energy in a smaller volume. Both are produced from hydrogen," Sand explains.
Where does hydrogen fit in the future energy landscape?
Is it a fuel we will see more of? And if so, where?
"Hydrogen fuel can be used either directly in an internal combustion engine where heat energy is generated, or indirectly to produce electrical energy and heat in a fuel cell," says Sand. She adds that hydrogen's energy density per mass is high - three times that of diesel or gasoline.
However, it requires a significant amount of space, as the energy density per volume is low. To reduce this volume, hydrogen must therefore be compressed at high pressure and liquefied at an extremely low temperature of minus 253 degrees Celsius," she explains.
Sand emphasizes that hydrogen is not an energy source, but an energy carrier. This means it must be produced through methods such as electrolysis, where hydrogen is separated from water, or steam reforming, where it is separated from methane - both energy-intensive processes.
The method used to produce hydrogen determines its environmental impact", says Sand.