Note that this is NOT about getting a longer battery life.
In fact, pretty much all tricks to put a limit on temperature/power consumption like this en up costing you battery life.
This is is about limiting either temperature or current use (on laptops temperature matters, in data centers current matters, but also temperature) due to external constraints.
We have a simple userspace app for example that can control a laptop temperature to just below the point that the fan would come on.
(it's very much prototype code at this point.. we're working on getting it more usable than on the one machine we ran it on).