Ken Thomas and his wife Delilah have invested in energy-saving windows and insulation for their Boca Raton, Fla. home. But in the dog days of summer, their electric bill can still top $400 a month. Ken Thomas hide caption toggle caption Ken Thomas Ken Thomas woke up this past Wednesday to find the power had gone out at his house in Boca Raton. A text message from his utility said a piece of equipment had failed at 2 a.m. By the time a repair crew showed up eight hours later, the hot, sticky Flo...