I think it might be worth pointing out that the concept of "base load" and "variable (top) load" are the result of conscious decisions made during the development of the electrical power system.

If you build a thermal plant (coal, oil, or nuclear energy with steam boilers and turbines), you run into a problem in that the components do not like to cycle from hot to warm to hot to warm. Thermal cycling like that causes them to wear out.

The solution to that is to develop a tariff or rate structure that encourages customers to use electricity during times when there is excess. For example, at night or on weekends, when traditional factories are closed. You end up with a situation where factories operate 24/7 because the cost of the overtime wages is offset by lower electricity cost. You encourage people to charge their electric cars at night "because the cost of electricity is lower then." But that is the result of how the rate structure is set up in order to protect the generating plant infrastructure.

Another way to approach it is to accept that the availability of electricity will vary depending on sunlight or wind, and to develop a rate structure that reflects that variability. Such a tariff encourages customers to deal with the variable supply by implementing demand management. Most factory operations, with the exception of certain types of furnaces (that do not like to be thermally cycled), can be curtailed or modified to align with variable electricity supply. Certainly most households can do the same thing.

The bottom line is that it is important to keep in mind that the idea of "base load" is an artificial construct that is in place primarily to protect a certain technology choice. That is why you need a natural gas supply: to protect the old-fashioned thermal plants that should now be retired.