Design of hydrogen-related heat integration in energy systems
Renewable energy systems increasingly use hydrogen to store energy and supply sectors that are difficult to electrify directly. However, producing, storing and converting hydrogen also generates or requires heat, and this heat is often overlooked. This thesis investigates when recovering and reusing such heat can improve the performance of hydrogen-based energy systems.
The research examines hydrogen-related heat use at three levels: individual hydrogen-storage technologies, complete renewable hydrogen supply chains, and wider energy systems in which electricity, hydrogen and heating are connected. The results show that heat recovery can substantially improve the efficiency of some hydrogen-storage chains. At the wider system level, its main value is not only saving energy, but also changing which technologies are built, where they are located and when they operate.
In a model of the Dutch energy system in 2050, using heat from hydrogen and related conversion processes for district heating reduced annual system costs by about €1.2 billion, or 2%. It also reduced the need for large heat pumps and batteries, while increasing the role of electrolysers and hydrogen transport.
Overall, the thesis shows that heat from hydrogen technologies should not be treated as an automatic by-product with guaranteed value. Its usefulness depends on heat demand, location, timing, temperature and infrastructure. Considering these factors explicitly can support more efficient and cost-effective energy-system planning.