What I found cool about the synthetic natural gas, is that Europe already has really good seasonal storage of natural gas. Hence the infrastructure is available for summer-time generation of gas using solar abundance that we use in winter for heating.

To my mind, it is seasonal load shifting that is Europe's long term energy problem. Winter energy demand has a bottom that needs to be met. We used to ensure this by stockpiling on seasonal scales. Without stockpiling, and with intermittent production, things will get hairy in winter.

Put differently, you can turn up a gas plant, but you can't turn up a windmill or a solar panel. That scares me.

Batteries and similar technologies are great for daily variation, but their cost per capacity does not allow for practical seasonal storage. For this I imagine we need cheap bulk storage, and can accept low efficiency because we can fill the stockpile with the cheapest excess power.