They claim that there will be a reduction in electric rate to offset (only partially, in many cases) the income-based fee.

The biggest flaw in this system that I see is related to how often the "household income" is determined, and what exactly it will consist of.

An annual income determination would be pretty bad, as income fluctuates month to month and the utility sends out monthly bills. Are they going to go back the prior year and refund some of it if your income went down (or charge you more if it went up)? By comparison, to get a health insurance subsidy under ACA (Obamacare), recipients are expected to go to the marketplace (exchange) and update their income online whenever there are significant changes. (However, many fail do to so, with unexpected results come income tax filing time). Will this now be necessary for utility bills as well?

And what is "household income"? Only what shows up on the federal tax return? Or how about the California tax return, which is different? What about non-taxable income, such as Roth IRA distributions, or Social Security when other income is low? What about child support or alimony, does that reduce the income of the payer and increase the income of the recipient for this purpose?

What if you rent out a room in your house or sublet part of your apartment? Is that person part of your "household", and how are you supposed to know their income?

The fixed fee is higher than my entire usage rate bill currently. It might make economic sense for some people to buy a battery + solar and cut electrical service entirely.

PG&E, Southern California Edison and San Diego Gas & Electric customers monthly bills will include a fixed charge based on income.