Our modern systems are predicated on the existence of electricity, which is a phenomenal discovery that helped propel the human race into our current civilization. However, electricity can be highly unstable and the systems that transport it are prone to disruption.
In an attempt to seed the idea of a wondrous future in a story I wrote a few years ago, I described one character as being surprised that a rediscovered colony was still using electricity. I never mentioned what his equipment operated on, but I would like to have a concept in mind should I choose to revisit the story.
A quick search revealed a discussion on Ars Technica from 2007 that indicated replacing electricity probably wasn't going to happen, the replacements just weren't worth it. In 2012, an optical replacement for electricity was proven viable, suggesting there may very well be a shift away from electricity sometime in the future. (This also reveals the difficulty inherent in prediction.)
Given what we know today, what is the most likely candidate to replace electricity in everyday life?