The additional storage needed when you need to store energy from the summer to feed the grid in the winter (instead of just for day/night and a few cloudy days) is not only orders of magnitude higher in raw capacity, but requires different battery chemistries that can hold charge for that long. 22% cheaper is a drop in the bucket.

> when you need to store energy from the summer to feed the grid in the winter

Surely you don't need to power 100% of winter hours with summer sunshine. Electricity isn't grain to be stored in a silo.

Most places humans live in also get sunshine in the winter. Less sunshine admittedly, but that's where overbuilding panels and interconnecting grids comes in. And even dark, cold places get windy.