For Texas residents, I just saw the commercial for TXU's free night from 10pm - 6am: http://www.txu.com/en/residential/pr...ee-nights.aspx
On their commercial, they suggested you can turn down your A/C as low as you want--which I know some people would love to do. On the other hand, this sounds great for any EV users.
The daily rate for the free nights deal is $0.139; this is compared to their current lowest rate of $0.101. But with 13kwh used each night, that is almost $39 (13 x 0.101 x 30). "free" each month.
(I wonder if you can charge up some batteries at night to let fans run throughout the day. I wonder how TXU would protect themselves from serious abuse. I do know that power companies that generate power from nukes in texas often pay wholesale buyers to take their excess energies, maybe TXU found some long term agreements. )