[aaronbee]

The Chrome team has been working on power efficiency improvements [1], some of them have gone into the already released Chrome 44.

[1] https://plus.google.com/+PeterKasting/posts/GpL63A1K2TF

[diminish]

Eww on emacs is also quite efficient, if power efficiency is a concern for you especially in low battery conditions.

[chrisgw]

Just make sure you have spacebar heating disabled.