Well, as statistics clearly show, there is a minimum demand 24/7. But that is just one characteristic number. That is the demand you always have to provide through the year. But at any time, more power is required, you have to provide that too. You cannot treat power demand over the "base load" any differently than the base load. Which type of energy production you might be using, you need to plan the ability to ramp up the production.
So it isn't that you require special sources for the "base load", that can be provided by solar+wind, if they are available in the necessary amount. It is just that "base load" can also be provided by slow power plants.
The big problem with nuclear from the grid side is, that they are the slowest power plants available. Consequently, (and because of cost efficiency) they are run at high power output levels 24/7, the rest of the grid has to adjust by being throttled or fast plants which can be ramped up and down.
Gas is the fastest type of classical power plants (together with water, but that usually has limited amounts). And as the fuel always was on the expensive side, there is quite an incentive of not running gas power plants too much. They would be a good company to renewables, as they can switch between 0 and 100% and back very quickly. And in a grid dominated by renewables, you would only rarely run them at high loads for longer times. And while they emit more CO2 than nuclear plants, they do distinctively less than coal powered plans.
In the long run, you can run gas plants on e.g. hydrogen produced from solar - the recent plans for extending gas power plants in Germany all included the requirement to be usable with hydrogen too.
The big problem with nuclear from the grid side is, that they are the slowest power plants available. Consequently, (and because of cost efficiency) they are run at high power output levels 24/7, the rest of the grid has to adjust by being throttled or fast plants which can be ramped up and down.
Gas is the fastest type of classical power plants (together with water, but that usually has limited amounts). And as the fuel always was on the expensive side, there is quite an incentive of not running gas power plants too much. They would be a good company to renewables, as they can switch between 0 and 100% and back very quickly. And in a grid dominated by renewables, you would only rarely run them at high loads for longer times. And while they emit more CO2 than nuclear plants, they do distinctively less than coal powered plans.
In the long run, you can run gas plants on e.g. hydrogen produced from solar - the recent plans for extending gas power plants in Germany all included the requirement to be usable with hydrogen too.