Windgas is actually pretty suitable for that last 1%. It may be 50% efficient to produce but it's easy to store large quantities of gas for long periods for those dark/still spells.
Counterintuitively that 1% of electricity generated from windgas will among be the most expensive "green" electricity but it will probably still be cheaper than nuclear power:
If you want to eliminate Carbon emissions, you do. The electricity supply network is always built for overcapacity or else bad things happen with frequency and device damage
https://energytransition.org/2017/07/germanys-worse-case-sce...