Power saving mode added to Opera Developer browser
Opera is an alternative browser using the same browsing engine that powers Safari under OS X and Google’s Chrome, so it should be pretty compatible with the sites you visit.
We are the first major browser to include a dedicated power saving mode, designed to extend your laptop battery life by up to 50% compared with, for example, Google Chrome. Depending on your type of hardware, it can mean several hours more browsing before you need to recharge your laptop.
Source: Power saving mode | Added to Opera Developer browser
I’ve mentioned before about using Safari on my old Macbook Pro to almost double battery life, so now I’ll have to try out Opera and see how it compares to Safari. Opera only compares itself to Chrome, but in that fight it isn’t hard to be the most energy efficient.
If you want to test this out, you’ll need to use the developer version of Opera, and as such, it may have bugs or not be as stable as the release version.