It is expected that in the coming years hydrogen producers and consumers will be connected via public (new-built and repurposed) transport and distribution pipelines. An important condition for setting up this system is the availability of a coordinated hydrogen specification (minimum purity, allowed trace components and bandwidth for Wobbe index) for infeeders and off-takers at all pressure levels in the networks. This HyDelta work aims to provide further insights (both technically and economically) into feasible specifications for hydrogen distribution grids in order to support operators in substantiating their strategies for feed-in, offtake and monitoring and controlling the agreed hydrogen quality. The insights delivered in this HyDelta research project can be used as basis for the development of an entry and exit specification for hydrogen in the Dutch distribution networks. The research results focus on the following elements:A. A techno economic analysis to deliver insights on the preferred hydrogen purity level for distribution networks from a market cost point of viewB. A technical infrastructural analysis to deliver insight on the technical network limitations, e.g. the effects of permeation and desorption on hydrogen quality in distribution networksC. How to manage hydrogen quality in future hydrogen networks (combining inputs from part A and B), including an infeed monitoring and measurement protocol Dit project is medegefinancierd door TKI Nieuw Gas | Topsector Energie uit de PPS-toeslag onder referentienummer TKI2023-HyDelta.