In summary, an open-source tool for transparent and reproducible techno-economic modelling of hydrogen production, called pyH2A, has been developed. Using pyH2A, a novel Monte Carlo-based methodology was conceived and implemented, which enables the study of how technological progress impacts the LCOH2 using the concept of "development distance". With this methodology it also possible to dissect the influence of specific technological parameters and determine how much each has to advance to reach a defined target cost range.