So to scale, for each GW of solar, you’ll need a GW of storage plus the energy reserve to take through the night. Can’t rely on wind here as that’s also intermittent.
And grid storage is energy intensive and sets up twisted incentives for those playing to get rich with energy arbitrage. Think solar farm generators owning their own grid storage and reducing solar output to sell at higher $ from storage. Because, with intermittent sources pricing has to be more dynamic.