So you focused on this but still no details on the baseless and handwavey “makes it more expensive” statement? Fine so now that batteries are affordable have you seen any deployments next to active NPPs, which today are used practically exclusively as base load and don’t need to follow demand peaks due to the ton of renewables+batteries taking that role? Did you look at that data from the French grid and how NPP production fits neatly in the base load with almost no variation? When all the NPP’s output goes to the grid no matter the time because that’s the definition of base load, what’s left to go into batteries?

Those times when renewable production is higher than the demand, the producer of renewables pays to feed it into the grid, not the NPP. That’s why they pay for the battery to store that excess, not the NPP.

Years ago when mostly unvarying power plants (coal, NPP) had to cover peaks too with help from hydro it made sense to have some form of storage. Today these plants don’t ever need to cover peaks. Their output is flat as a pancake almost and fits perfectly the role for base load. Peaks get covered from varying sources which can then really benefit from using batteries because first, they have variable production and second, they would pay for any excess power fed into the grid. Batteries help turn to profit what otherwise would be an expense. This is not the case for NPPs.