The Ubuntu page for my device states the following at the bottom (Known Issues)

PowerTOP reports that the module for the 10/100/1000 interface wakes the processor 100+x/sec, accounting for >50% of wakeups on an idle system. This dramatically shortens battery life. One potential solution is to unload this module if you only use wireless.

I only use wireless, but I could not find instructions to "unload the module". I have a feeling if I try something related to this, but not the same, battery life will not improve and my eth0 won't work. Anyone have a good guide on this?