According to the German energy regulator Bundesnetzagentur gas production in the Netherlands and Germany is in steep decline and a switch to countries supplying H-Gas is required to meet German demand http://www.bundesnetzagentur.de/SharedDocs/Downloads/DE/Allgemeines/Bundesnetzagentur/Publikationen/service/UmstellungLGas.pdf?__blob=publicationFile&v=3 (German language version only).
With a view to making the switch, German energy companies and the Bundesnetzagentur claim that the end-consumer will not be affected. They are pointing towards § 19a Energiewirtschaftsgesetz. According to sentence one of this paragraph, the companies have to bear the costs of switching from L-Gas to H-Gas.
However, the paragraph also entails a second sentence, which establishes that the costs of changing from L-Gas to H-Gas do not merely have to be borne by the users of the particular grid where the switch is taking place. Instead, the costs have to be re-allocated amongst all gas grids in Germany. This might result in higher tariffs for gas transportation and such price-increases might then be passed-on to German gas customers. Thus, the end-consumer in the whole of Germany could ultimately pay the bill.
Information of the Bundesnetzagentur might be accessed, in German only, via: http://www.bundesnetzagentur.de/cln_1421/DE/Sachgebiete/ElektrizitaetundGas/Verbraucher/NetzanschlussUndMessung/UmstellungGasbeschaffenheit/UmstellungGasqualitaet-node.html