The parent post is claiming that the storage solutions are right now cheaper than the alternatives. If they are already here in terms of costs then bringing them online should be fairly quick ordeal.

I agree with you however that it will take much longer than 3 years. Lithium batteries can be done today for the kind of storage solution which they are suitable, but not for wind. The green hydrogen might work, but we have yet to see large scale production and we are nowhere near to have it operate as an alternative to natural gas on a nation scale. Germany should really make an attempt if they wish to take a different path from France, but it will likely take a few decades if its successful.