I received a letter from ComEd and noticed my electricity per usage increased from 5KW per week to 20KW per week in new condo.
Because I used 158KW per week, it will be around 600KW per month for a house hold with single person, that seems really high.
As a reference, Americans use 903KW per HH per month (from http://www.eia.gov/tools/faqs/faq.cfm?id=97&t=3).
Japanese HH use 300KW per month, (http://www.fepc.or.jp/enterprise/jigyou/japan/)
The research shows ComEd offers hourly pricing rate - which is running a from 2 cents per KW to 5 cents per KW. Because fixed price for ComEd is 6 cents per KW, I should be able to save around 33% or so by switching to variable rate.
Moreover, if you allow ComEd to turn off your AC in peak time, they will give you $10 per month in the summer time, that will be 11% discount.
Also it looks like there are Wifi Thermostat that I can connect via phone — this will allow me to change temperature or start/stop AC from outside, probably it is a good investment.