Most importantly, there are events, vendors, and just plain fun this year's Expo to plan for. I know "icksnay" on the fun aspect.
You are probably thinking, "How do I go to the boss and get permission to go to an event that has fun too?" Well I had those problems too - that is until I started my own company. Now I work twice as hard, but I don't have to worry about the boss and I take opportunities for fun where I find them. When I worked at a utility it wasn't unusual to put in 60 hour plus weeks, so why not have a little fun with work.
The main reason I want to go to the T&D Expo is to learn, but I have found learning is improved with a little relaxation (fun) added. So tell your boss you need to learn more about the smart grid technologies and the fun is going to help you retain what you learn.