A recent call for projects related to the development of new hydrogen applications and infrastructure in France has revealed renewed interests of city authorities and regions for water electrolysis technologies in order to achieve their energy transition goals. By taking into account the expected business models of these very flexible systems, the cost of providing flexibility services to the distribution system operator was studied for three types of hydrogen infrastructures connected to the electricity distribution grid. The contractual framework was divided into a multiyear commitment contract and a day-ahead activation contract. The calculations of the average costs for the flexibility provision to the DSO reflect these two parts.