Er, they mentioned the Mac because that's what they were using? It's a personal story of discovery. It's just weird here, because it's discovering something so basic.
I 100x increase my Mac battery by putting it to sleep.
This post is newbie in all senses. He could get a console over the webpage, check the javascript or offending logic and create a post like this:
Increase your users happiness (and battery life) by improving XYZ (e.g. polling behaviour) on your webpage. -Improving responsive design with battery life in mind
which identifies a problem and propose a solution.