This is not the definition of grid-friendly. I am just calling out that windmills could never serve as base power plant, and serving as peak power source has a serious side effect of requiring gas turbines to provide smooth energy production that does not stress the grid. You do not change the output of your base power plant on a daily basis, this is why it is called base. For the peak coverage you have something that is easy to change the performance of.

The Ludington Pumped Storage plant (the largest in the world at the time of construction) was built to store nuclear and use it for peaking.

So the same storage tech that is needed to increase the share of renewables we can rely on also makes things better for nuclear.