Large areas of Canada ideal for future hydrogen production, global analysis finds

Researchers at the Paul Scherrer Institute PSI have analyzed which regions of the world could produce hydrogen most cost-effectively in order to build an economy based on this alternative energy carrier rather than on fossil fuel-based alternatives.

One of their conclusions is that simply replacing fossil fuels with electricity and hydrogen will not be enough to end greenhouse gas emissions. The study is published in the journal Nature Communications.

Switzerland aims to become climate neutral by 2050. This means that from this year onwards, no additional greenhouse gases should be released into the atmosphere in order to slow down climate change. The electrification of transport, industry and households, as well as the switch to renewable electricity sources such as hydro, wind and solar energy, are key elements in achieving this goal.

However, electricity cannot be used everywhere as an energy source: its storage density is insufficient for certain applications. To meet greater needs, hydrogen must take over. Aviation, agriculture and steel, for example, represent applications that could significantly reduce their impact on the climate thanks to hydrogen, sometimes converted to produce fertilizers or synthetic hydrocarbons.

The researchers, led by lead author Tom Terlouw and project manager Christian Bauer from PSI’s Energy Systems Analysis Laboratory, collected geographic and economic data as well as forecasts to describe the development of a hydrogen economy under four different scenarios.

Depending on the scenario, hydrogen demand is expected to be between 111 and 614 megatons per year in 2050. In the first scenario, the world continues to operate as usual and still relies on fossil fuels. In the fourth, most optimistic scenario, the world adopts rigorous climate protection measures and manages to achieve the 1.5 degree target. Currently, around 90 megatons of hydrogen are produced worldwide each year.

Where is there enough space for electrolysis?

Hydrogen can be produced by different processes. Steam methane reforming, in which the element is extracted from natural gas, oil or coal (i.e. fossil fuels) under high pressure and temperature conditions, is currently the dominant method. The most optimistic scenarios assume that PEM electrolysers will be increasingly used.

These devices use electricity and a polymer electrolyte membrane to split water into hydrogen and oxygen. If only green electricity from renewable sources is used, the process can operate without fossil fuels. It produces up to 90% fewer greenhouse gases than steam methane reforming.

The central question, however, was in which regions of the world hydrogen should be produced using this technology. “We mainly applied economic criteria,” explains Terlouw, “in other words, we looked at where production would be cheapest.”

Two factors proved decisive: where can the enormous demand for green electricity needed for electrolysis be met most efficiently, thanks to the abundance of alternative energy sources such as wind and solar? And where is there enough land suitable for building the necessary production facilities?

Canada is ideal, Switzerland less so

Much of Canada, for example, is proving to be one of the most suitable regions for hydrogen production. “There are lots of open spaces, very exposed to the wind and therefore ideal for installing wind turbines,” says Terlouw.

“In addition, there is plenty of water and the political situation is stable – although we did not take these two criteria into account in our study. But of course, the availability of water for electrolysis also plays a role, as does the question of whether the country concerned is one from which hydrogen can be reliably imported.”

In addition to these criteria, the central United States also offers good conditions, as do parts of Australia, the Sahara, northern China, and northwestern Europe. Either because there is enough sun to produce solar energy, or because there is plenty of wind and open space to build wind turbines and hydrogen plants.

Industrialized countries in Central Europe, such as Switzerland or Germany, are less suitable for hydrogen production, as there is virtually no land available for wind turbines and solar radiation is relatively low. Other densely populated regions and countries, such as Japan or the vast coastal areas of the United States and China, could only produce hydrogen at a relatively high cost.

“We identified a certain disparity between regions with a high demand for hydrogen and regions with a high capacity to produce it efficiently,” concludes Terlouw.

A hydrogen economy should overcome this disparity through global trade, but this requires additional energy and political cooperation. Ultimately, the energy requirements are due to the fact that hydrogen is usually transported in compound form, for example as ammonia or methanol. The volume of the pure gas is far too large, while the much more compact liquid form requires massive cooling.

The ecological disadvantages of green hydrogen

The study also looks at other environmental side effects of a possible hydrogen economy, which are often ignored by the public. “First of all, it is important to point out that even a functioning hydrogen economy will still produce residual greenhouse gas emissions,” says Terlouw.

The study estimates these residual emissions at nearly one gigaton of CO₂ carbon equivalents per year. Total emissions currently stand at around 40 gigatonnes. “It will not be possible to reduce the climate impact to zero,” Bauer confirms.

This is mainly because the production and distribution of hydrogen is itself associated with emissions.

On the one hand, an estimated 2.5% of hydrogen is released into the atmosphere through leaks, with hydrogen itself acting indirectly as a greenhouse gas by promoting the formation of powerful greenhouse gases such as methane and ozone.

On the other hand, electrolysis systems have so-called embodied emissions, which occur during the production and transportation of the necessary materials, even if the final systems operate on green electricity.

“Many of the systems and machines used in a hydrogen economy are manufactured in countries where, in the near future, their production will largely depend on fossil fuels,” says Terlouw. “Most solar panels today come from China, where most electricity is still produced by coal-fired power plants.”

Anyone who truly wants to become climate neutral must offset these residual emissions by capturing and removing equivalent amounts of carbon dioxide from the atmosphere. Technologies such as direct air capture, in which special equipment removes the CO₂ Another way to do this is to use carbon in the air. Or reforestation, where planting additional trees can capture some of the carbon in the air.

Critical materials

According to Terlouw and Bauer, in addition to the impact on the climate, the hydrogen economy should not be forgotten. Machines and systems use a whole range of materials that are either harmful to the environment or whose production is harmful to the environment.

Wind turbines, for example, contain rare earth permanent magnets whose extraction in China does not meet European environmental standards. The catalyst used in PEM electrolysis is iridium, a metal considered problematic simply because it is very rare. And the large amounts of land and water required for hydrogen production could also be a negative environmental factor.

“Finally, there is the big question of social acceptance,” Terlouw points out. “Will people accept coastal landscapes being occupied by large hydrogen production plants, for example?” In water-scarce regions, seawater would first have to be desalinated before being electrolysed, which requires additional energy and land.

“In the current study, we have not yet taken these factors into account,” Bauer admits. “Further studies must follow. We want to show the possibilities of achieving the energy transition. Whether we will pursue them and how rigorously is ultimately a socio-political question.”