Take a real close look at the scale on that dashboard. While peak power is about 9Gw, sometimes up to 12GW, the lowest power output overnight is 6GW and that's

Take a real close look at the scale on that dashboard. While peak power is about 9Gw, sometimes up to 12GW, the lowest power output overnight is 6GW and that's the absolute bottom. So in a standard 24 hour day, there is at minimum 6GW of capacity which is always available and always demanded. And for most of year that's 2/3rds of the total demand which ever applies. The question you are not answering is whether the cost of building a proportionally larger nuclear plant - i.e. one which can meet the upper ends of this scale - is substantially more expensive then a smaller one. The answer is pretty obviously no: nuclear plants are front-loaded in capital and construction costs, but their relative size has very little impact on the cost of building them, or their maintenance needs, or even fueling costs. The reality is renewables haven't got anything on that except from an electricity market which mostly doesn't care about them. Start asking renewable generators to well you guaranteed kilowatt-hours throughout the year and watch the "cheap" power skyrocket in cost.