I went on an almost 2 week vacation, could not log in and play, and got an email that since I had been gone for 7 days, some of my buildings were being disconnected from the power grid. I scowled and found out that the resolution was to log in again... But obviously I have, and half of my planets are still paralyzed with a flashing lightning bolt over key buildings like resource storage. I have tonnes of surplus power, but cannot figure out as to what to do to get these buildings powered up again!

Any tips would be HIGHLY appreciated.

Use Energy Supply Towers to extend the power grid and connect buildings that aren't in range of power plants.