Storage is of course the way to overcome grid volatility but so far there are few economical options. As I mentioned, few studies have been conducted on this volatility component and cost, but my understanding is that current storage options are uneconomical relative to nuclear, and especially relative to coal and LNG. Hydro storage is ~70% efficient but it's obviously only feasible in mountainous regions. It's actually cheaper to significantly overshoot renewable capacity to compensate for slow days, but if we're now building 2-3x peak capacity then the cost equation shifts considerably.