Los Angeles is somewhat unusual for California in that its electricity generation is owned by the city, instead of being a privatized monolopy.
It is a 3 Tier system, where, during the summer, the 1st tier (350 kWh per month) is the cheapest and the 3rd is the most expensive. Oddly, during the winter, all three tiers cost the same. Go figure.
Anyway, looks like a kWh costs about 0.14USD on Tier 1. I don't have air conditioning, so it would be pretty hard to exceed 350 kWh. 350 kWh works out to an average power consumption of 500W constantly all month long. I use about half that.