I was on Flight 1146 (787 #3902) this morning, when we had a power/electrical issue. We've ended up being diverted to MSY and they are bringing in a replacement aircraft to continue on. About 75 minutes into the flight the electrical power flickered a couple of times and then I noticed us making a long right hand turn. I was expecting us to be headed back to IAH. Once the AVOD got rebooted I checked the online map and it showed us headed to MSY with a landing in 30 minutes. Up till this point no announcement had been made, so on the way back from a trip to the washroom, I asked one of the FA's when they would be making an announcement about the diversion. She was shocked that I knew about it, and asked how did I know. I calmly replied that the flight map now shows us heading for a MSY landing at 9:25. A few minutes after this, one of the FA's announce the diversion.