The fly in the soup is that utilities have to run “parallel physical services”. Those services are in generating capacity. For every wind or solar farm, the utility, which is responsible for “reliable power” needs to build, maintain & have available an “old school” coal or oil generating plant.
Consider an analogy with your home, every modern home has an HVAC system for heat and AC. But in the analogy, your modern home will have two HVAC systems, one will operate when God provides sufficient wind and sun. And the other HVAC system for when sunless, windless days befall us.
But you’ve doubled HVAC purchase costs, 2 identical physical systems, different power sources. In addition to purchase, there is installation costs, maintenance and repair costs, etc. That’s what the utilities face. The days of the utility manifest for providing safe, inexpensive and reliable service are gone. Utility CEOs don’t even fight the Public Utility Commissions (PUC) anymore about fulfilling their manifest as a monopoly. If PUC says the utility needs 50% of their power grid to be renewable sources, the utilities sets into motion building “parallel physical services” and add the additional costs into the rate base.
The widows and orphans that own utility stocks are protected bec John Q Customer picks up the tab threw higher utility bills. Remember utilities are guaranteed a profit so long as they provide safe and reliable service, inexpensive not so much. But CEO replies to unhappy customers that the PUC instructed us what we need to do for our guaranteed profit, customer be D@mned.
Electric utilities have to plan for contingencies in re capacity. The generating mix has to be planned such as to avoid excessive dependence on a sibgle type. A dry winter in CA for instance can reduce hydro generating capacity over the summer.
And as you note, “green” systems are much worse in this. Around the world the go-to backup for both “renewable” systems and for peaking has been natural gas, both pipeline and LNG. Fortunately gas turbine plants are both cheap (relatively) and quick to build. An unheralded development btw.
Except in CA, of course, because of political idiocy.