While this article is about Windows, the situation is very different on Macs, where Safari completely trounces Chrome 36 in terms of battery life, but also rendering performance and UI responsiveness.
[1] http://www.reddit.com/user/5HT-2a/m/machelp/search?q=Chrome+...
[2] http://www.reddit.com/r/mac/comments/2d2lim/a_thoughtwarning....
[3] http://www.forbes.com/sites/ianmorris/2014/07/21/google-will...
Not that I'm claiming that this is proof that Safari is better than Chrome, but in my experience it uses a fraction of the CPU and gets the same job done.