Power to gas (PtG) is a technology for producing hydrogen and methane using electricity, while power to liquids (PtL) is an electricity-based process for the generation of liquid fuels. Jointly with other so-called power-to-x technologies PtG and PtL make it possible to provide renewable energies for all applications. This position paper assesses the role and prospects of the power-to-gas/power-to-liquids (PtG/PtL) technology in a fully renewable energy system and identifies, in particular, the challenges for integration and further development of this technology in the ongoing transformation process, which should be addressed in the next few years.