The versatility of hydrogen as a solution for decarbonization has created a lack of consensus and clarity on the industries that really need it. Hydrogen is sometimes described as a Swiss army knife, because it seems to be able to play a role in almost every sector. It can be burned to generate electricity or heat, serve as a carbon-free input to produce “green” steel and fertilizers, and create electricity from it in a fuel cell to power passenger cars, heavy trucks, buses, airplanes, and ships. cargo on the high seas.
Hydrogen must be a priority for ‘difficult’ sectors and must be green
In theory, the hydrogen can be used to decarbonize almost all sectors. But just because you can, doesn’t mean you should. As one of the decarbonisation tools, hydrogen must prioritize its use where energy efficiency and direct electrification are not efficient. In particular, the potential of hydrogen must be used to decarbonize the hardest-to-reduce sectors quickly and cost-effectively, making it a necessary part of the clean energy transition.
One of the factors limiting global decarbonization is the scarcity and price of renewable electricity which is used to produce ‘green hydrogen’. The world needs a much cleaner electricity infrastructure Just because of population and economic growth, the energy consumption will double by 2050. Today, globally, only 10% of electricity comes from solar and wind power. If the electricity required to produce green hydrogen to decarbonize heavy industry and transport is added to these figures, power consumption could triple.
In this scenario that considers the use of electricity at a macro level, it is important to prioritize the reduction of consumption and the more efficient use of renewable sources. Many of the cases of commercial use of hydrogen at the micro level of today, to heat buildings, generate power or power light vehicles could be executed through investments in direct electrification and efficient energy management, so as not to consume excessive resources that will be necessary in the future.
There are applications where energy efficiency and direct electrification are prohibitively expensive, impractical or simply impossible as is the case with steelmaking and shipping. In these cases, hydrogen, with its flexibility, technological maturity and relatively low cost, is one of the main solutions to achieve decarbonisation.
The specific applications in which hydrogen is the best option may vary by geography, especially as developed economies have different land constraints and limited ability to develop renewable capacity. But even before considering these limitations, there are several high priority hydrogen applications where political decisions and investment should focus: fertilizer production, petrochemicals and refining, steel production, Marine transport and, in some markets, heavy long-distance road and rail transport. These sectors need hydrogen to decarbonise, are ready for the technological transition and contribute substantially to global emissions. Over time, hydrogen is likely to expand beyond these main applications.
The next graphic indicates the reduction in carbon emissions from the use of each kilowatt-hour (kWh) from a renewable electricity source, whether used directly in electrified end-uses or indirectly for the creation of hydrogen. This quantitative evaluation validates the philosophy that governs the use of hydrogen in priority applications: use hydrogen where it cannot electrify. Direct use of electricity wherever possible offers the greatest emission reduction potential, largely given the low efficiency of hydrogen use in these applications (building heating, power generation and light transportation).
Passenger transport in light vehicles and heating of buildings are the most suitable applications for direct electrification before the use of hydrogen, as can be seen in the graph. The efficiency of battery-powered electric vehicles for passenger transport often makes direct electrification the best solution.
Applications that need green hydrogen
Nowadays, hydrogen is already widely used. The problem is that much of it is hydrogen created from fossil fuels, with a high emissions load. Hydrogen production for fertilizers and oil refining currently contribute about 2% of global emissions. The use of green hydrogen to decarbonize these uses it is a necessary application. The European Union has committed to replacing all “grey” hydrogen derived from natural gas by 2030. These sectors could serve as drivers to expand the supply chain and drive cost reductions that clean hydrogen generation technology implies.
Maritime transport is responsible for approximately 2.5% of global emissions, a figure that is increasing. It is a sector that has few decarbonisation options, especially in offshore travel. Electrification is possible for regional travel, but long-distance shipping, which accounts for most of the sector’s emissions, needs hydrogen or its derivatives (ie ammonia or methanol). The biofuels they present an alternative to hydrogen-based fuels, but feedstocks are limited and are largely prioritized for use in aviation rather than the shipping sector.
The road transport, which represents approximately 4.5% of global emissions, is already assuming the need for the use of hydrogen. Due to the limitations of the energy density of electrochemical batteries and the long recharging times involved in recovering autonomy, heavier vehicles that cover long-distance routes must resort to hydrogen.
Beyond transportation, hydrogen is a priority in the steel making, given the magnitude of the sector’s emissions and its limited alternatives for decarbonization. Steelmaking is responsible for about 8% of global emissions, primarily due to the use of coking coal that removes oxygen from iron ore to create pure iron, a chemical process called “reduction.” Replacing coking coal with hydrogen in this reduction process is the most promising and mature solution to decarbonize steelmaking.
Applications that will need hydrogen in the future
Aviation has several decarbonization options, the feasibility of which varies depending on the size of the aircraft and the distance to be traveled. For shorter routes, electrification is an option. For longer routes, biofuels, synthetic fuels or hydrogen emerge as alternative solutions. However, there are technological, design and regulatory hurdles that need to be overcome before hydrogen is ready for use in this sector. Until then, emission-free aviation is restricted to the use of direct fuels that do not require a technological change in aircraft. To help accelerate the decarbonization of aviation once aircraft-side technology is ready, current hydrogen infrastructure must be built with an eye to providing future supply at airports.
Hydrogen is key to meeting climate goals, but its deployment in instances where energy efficiency and direct electrification are better options will hamper the ability to decarbonize the energy system quickly and cost-effectively. To maximize the efficient use of clean electricity throughout the system, hydrogen should be used when these solutions are not possible. Heavy trucking, fertilizers, oil refining and petrochemicals, and steelmaking are hydrogen applications that no one disputes need hydrogen. Over time, aviation and long-term energy storage may come together.