We all know it: for various reasons, gas and fossil fuels are no longer an option. The climate crisis is becoming more and more visible and the plans of various governments more and more ambitious. The industry needs to become CO2 neutral and participate in the energy transition as well. A good renewable energy carrier, such as green hydrogen, is much needed.
Hydrogen is the best clean substitute for gas so far and offers the industry many opportunities for the future. Currently, hydrogen is mainly used for different types of products in the chemical industry. In the future however, it will increasingly be used for high-temperature processes, such as steel production that currently uses natural gas or coal.
Reversed production cycle
In hydrogen generation, electrolysis – the process by which you generate hydrogen - is the magic word. Using hydrogen in the industry effectively reverses the current cycle of making products. Now, long carbon molecules are 'cracked' in refineries into the desired end product. Instead, in the case of electrolysis, these products will be built from small molecules produced in a green way.
What is already possible
Electrolysis currently has two market-ready technologies:
- The alkaline systems that have been used on a large scale (6-100 MW) for years, especially in chlorine production.
- The Proton Exchange Membrane (PEM) systems. These have a smaller physical footprint, produce pressurised hydrogen and are suitable for coupling to a fluctuating energy source such as a wind farm. The largest PEM systems have a capacity of about 10 MW.
The grid is off limits
The PEM systems are so far the most suitable for green hydrogen. You can use them well for energy from solar panels and wind turbines. However, it is important that this is done without adding energy from the public electricity grid, due to capacity problems in the public electricity grid. This also prevents energy from fleeing back into the grid.
Electrolysis suitable for fluctuations
Fortunately, though, electrolysis is ideally suited for capturing the fluctuation between energy production and consumption. The development of new power electronics and new control systems to match the power supply of electrolysis with the availability of solar and wind energy and its fluctuations is important for the future. For the safety, quality and availability of electricity, the system must be able to react quickly to fluctuations in the electricity grid and switch quickly between different sources. This is also known as ‘peak shaving’.
Switch to 'island mode'
But is there enough capacity to carry out electrolysis with green power? There is if an installation is developed where the energy flows remain balanced between generators and consumers of energy. 'Island mode' is a new alternative to 'peak shaving'. At times when more renewable energy is generated than can be absorbed by the electricity grid, energy sources can also be disconnected from the public grid and fully deployed for hydrogen production in an independent local electricity grid. This local grid, like an island, has no connection to the public grid.
In the future
Hydrogen production in 'island mode' is an innovative and ambitious solution for large-scale production of green hydrogen from renewable energy. In fact, green hydrogen can also be exported to nearby countries through a European network of hydrogen pipelines.
Would you like to know more about the potential of electrolysis and the latest developments on green hydrogen? Download our white paper ‘Towards a more sustainable industry with green hydrogen’.
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