Didn’t know what wind gas was until I saw this presentation on “Towards 100% renewables and beyond power: The possibility of wind to generate renewable fuels and materials” by Michael Sterner of Fraunhofer IWES institute. Page 16 has this diagram:
The process described is actually a way of storing energy. Electricity from wind power is used to produced hydrogen and converted to methane. As such it can be stored (e.g. in gas pipelines) and is available to generate electric energy during peak hours. Efficiency is only 36%, but alternatively wind turbines would have to be cut-off if they can’t feed their power into the grid. Other storage alternatives (such as pumped storage power) are capacity limited.
An overall interesting presentation, access the PDF here.