As someone who isn't in California, it's understandable that you might think this. It is, fortunately, wrong.
The biggest driver of costs of electricity in CA are (1) paying for damages caused by grid-initiated wildfires, and (2) paying to upgrade the grid to prevent future cases of (1).
This information comes directly from the government who approves rate increases for regulated utilities, and who has to publish their spending. PG&E, the primary power company, is also a public company and their financials are therefore public.
Rooftop solar specifically (and not general grid-scale renewables) do shift the cost balance of fixed-cost infra and consumption based usage, but the wildfire issues dwarf this.
The biggest driver of costs of electricity in CA are (1) paying for damages caused by grid-initiated wildfires, and (2) paying to upgrade the grid to prevent future cases of (1).
This information comes directly from the government who approves rate increases for regulated utilities, and who has to publish their spending. PG&E, the primary power company, is also a public company and their financials are therefore public.
Rooftop solar specifically (and not general grid-scale renewables) do shift the cost balance of fixed-cost infra and consumption based usage, but the wildfire issues dwarf this.