What will determine if power to gas will be an important technology in the energy transition over the next years? One can look at the development of a technology as a process that takes place in a technological innovation system (TIS). The TIS includes all actors and institutions that are involved in the development, diffusion and utilization of a technology. For a technology to develop successfully the TIS should fulfil several functions. For power to gas technology several pilot projects are realized, studies are carried out and funds are available both for projects as for research. The functions called entrepreneurial activities, knowledge development, knowledge exchange and resource mobilization are all met. The function that faces the most problems is called market formation. There is not yet a regulatory framework for power to gas. Investors in power to gas also need to be rewarded for the benefits that they realize such as the avoided capital cost of extra infrastructure, the enabling of maximum utilization of renewable electricity and the increase in renewable content of the gas networks. Policy directed at market formation is therefor recommended.