I see the same type of behavior on my MacBook Air (13-inch, Mid 2013)

Specs: Proc : 1.4 GHz Intel Core i5, Memory : 8 GB 1600 MHz DDR3 Graphics : Intel HD Graphics 5000 1536 MB

Even when just left open with one window and nothing entered into it I see between 1.3-1.6% energy impact on each of the WolframKernel processes constantly. These processes also show a CPU usage of ~0.7% each that never goes away.

On desktops this is fine, but on something like a macbook air this has a significant impact on battery life.

I even took screenshots :)

Thank you for time and consideration of this matter, Jon

I know all this, and still Energy tab shows considerable use even when I have nothing but a kernel and FE idling, even without content on the notebooks. I believe FE and kernel(s) perform some sort of copious polling, which keeps CPUs away from deeper sleep states. This consumes almost zero CPU time, but not so for the energy. At least Activity Monitor thinks so, and I believe it's quite correct. Also, highly scientific "how warm frame just on front of display is" methodology points towards this direction. It tends to be constantly warm when Mathematica is idling on the background.

I have disabled discrete graphics. I haven't made any specific experiments on measuring battery lifetime, but usually Energy view correlates well with real energy use.