FYI, this article indicates it’s probably because of the recent Time of Use (TOU) rate plan, which you can opt out of. From the article:

When TOU pricing was first put into effect, customers were transitioned into TOU pricing unless they OPTED OUT. Edison points out that if you ARE seeing bills skyrocket with TOU pricing—you CAN still use the rate plan comparison and see if something called a “tiered rate plan” is better.

Under a tiered rate plan, the bill you pay is based on the TOTAL amount of energy you use, regardless of WHEN you use it. Rate Plan Comparison | Rates | Your Home (sce.com). SCE also points out that there are potential discounts for those who qualify and are having trouble paying their bills.