17.05.2021 | Hydrogen in practice
Green hydrogen, which is produced with electricity from renewable energy sources, is considered a key technology for the energy transition and de-carbonisation. Axpo intends to build up know-how in this area and realise leading-edge projects using H2.
In continuing to develop its strategy, Axpo has taken some first important steps. In the future, the company will focus on three pillars: In Switzerland, on its leading role in Switzerland's transition to a CO2-free energy future and internationally on the customer and trading business, as well as the expansion of renewable energies. In addition to hydropower, wind, and solar energy, battery storage and hydrogen technology will play an increasingly important role.
Today, hydrogen is primarily used in the chemical industry to manufacture nitrogen fertiliser and in oil refineries to produce petroleum or synthetic fuels. Hydrogen is also being used in the area of mobility, for example hydrogen-powered passenger cars, lorries or public transport buses.
Whilst the auto industry is still disputing whether e-vehicles with batteries or hydrogen drives make more sense, one thing is clear: Hydrogen could find practical application in the transport industry, particularly in the area of long-haul and heavy load transport – as well as in shipping and aviation.
The use of H2 could also makes sense for low-emission steel production or metal processing.
Furthermore, additional gaseous and liquid synthetic energy carriers based on hydrogen could be used in the area of chemical production and refineries. Cement, glass and ceramic production could use hydrogen in combination with carbon capture. Hydrogen in fuel cells could also be used for heating.
Hydrogen could ensure year-round energy supply with renewable energies as a long-term storage technology along with batteries or methane. Although the "power-to-H2-to power-technology" is fairly straight forward in technical terms, it remains very expensive for seasonal storage owing to overall high production costs.
For many, green hydrogen is the guarantee for a successful energy transition. Experts see a great deal of potential (McKinsey projects that green hydrogen will become competitive in the 2030s), but also warn about the hype.
But let's take a look at two concrete examples.
In the year 2020, steel production was the largest industrial CO2 emitter in Europe with 22 per cent. According to the Paris Agreement, becoming climate-neutral by 2050 means companies will have to adjust their production to new, widely applicable, climate-neutral technologies in the next five to ten years.
Although CO2 emissions could be decreased through a combination of CO2 storage and the use of biomass in furnaces, they cannot be reduced to zero with these solutions. Other options, such as plasma direct steel production or electrolytic reduction methods are still in very early stages of development.
According to industry experts, hydrogen-based direct reduction is the most developed technology and – as soon as there is enough green energy – it can be used ecologically in the steel industry. In direct reduction, iron ore instead of coke is reduced to steel with the help of natural gas or hydrogen – accordingly the coke-based furnaces would have to be replaced.
However, the total energy needed for climate-neutral steel production is high. According to “enerigeexperte.org” this amounts to about 120 TWh per year. As a comparison: The world’s largest facility for hydrogen electrolysis is currently being planned in Hamburg. At optimal operational performance, it can generate just 1 TWh per year.
Additional CO2 reduction potential is also available in buildings using hydrogen for energy storage and in fuel cell heating systems. However, according to a study by the Fraunhofer Institute for Renewable Energies, the principle of less is more is applicable here. "Hydrogen should only be used directly in heat generation when there are no other economical alternatives." Because: The required renewable energy volume to generate low temperature heat with hydrogen is 500 to 600% higher than that of heat pumps.
Fuel cells function like small cogeneration plants. They transform hydrogen into electricity and heat. The combined use of both products results in efficient utilisation of the original primary energy. These types of fuel cell power plants could be realised in various sizes. In addition to decentralised power plants with an output between 200 kW and several megawatts, small systems are an interesting option. In the performance range of common household heating systems, these systems can supply heat energy as well as electricity that could, if needed, be fed into the power grid. Together, millions of these household fuel cells could form a power plant. A power plant that could be used as a whole for ancillary services (control reserves).