Typically such lulls in energy production will last for a few days and to meet this period we need deep pumped hydro storage that will be able to support the grid for multiday periods. Careful site selection means has resulted in sites with substantial storage and an ability to meet these future challenges.
Such a pumped hydro station is quite challenging to model how it would interact with the national grid so we have created a digital twin of such a power station. It has taken years of work but now means we can predict with high confidence its operation on a minute by minute basis. It can use detailed historic data adjusted to allow for changes in volatility that will come with variable renewable energy sources.
The article from Acciona is a useful summary of how pumped hydro has been used and while reading if you keep in mind the changes coming it can offer a good insight into how we can strengthen our future grid.