"Baseload energy" is a completely misguiding term. The base load is a purely statistic artifact. Operating the grid means, that the electricity generation exact

"Baseload energy" is a completely misguiding term. The base load is a purely statistic artifact. Operating the grid means, that the electricity generation exactly matches the consumption at all times. For this it doesn't matter, whether the demand is close to the base load or high above it. If the electricity generation doesn't match the consumption, you get grid failures. Overproduction can be as problematic as underproduction. The base load is nothing especial, only the fraction of the maximum load of the grid, that is always drawn and can be served by power plants which cannot be regulated well. Which most of the time of the day is a big disadvantage of those power plants. If there is a demand peak, they can't serve it. If their overall output is too high, you cannot turn it down quickly enough. As coal and nuclear power traditionally had a large part of the supply and both are quite slow, for decades the net was designed to raise the "base load". Like in Belgium, where all highways were illuminated at night to consume excess nuclear energy... The good news about wind and solar is, they can be switched off quickly at any time. Their disadvantage is, and that probably is, when you talk about base load, that the maxim power output depends on the weather. With a coal plant, you can put more coals into the fire, with solar, you need to wait for sunrise. That is indeed a challenge and requires storage and grid planning to compensate. Larger scale grids which mix wind and solar are much less affected by the. But nothing of this has to do with the base load. And with nuclear: yes, wind should beat nuclear easily in the aspects of cost and CO2. But the most important metric is: the cost of building new nuclear plants is prohibitive. Just compare the costs of the most recent English nuclear plant with new wind installations. They are about 1/3rd of the cost and not have any of the problems of nuclear energy attached (operation risk, nuclear waste).