Granola is a power management software company. They replace the built in OS power management software with theirs. It is more efficient and scales performance better. If fact they claim you won't ever notice its running. I run it, and I don't. The screenshot above is from my computer. I am saving 41% CPU energy and I never notice. Also, it looks like I am saving 2 dollars per month just by running a piece of software. While the environmental impact is awesome, its impact on my PG&E bill is where I value it most. If I multiply this by the number of machines running in my house, the saving become significant. Now as I have tested this on multiple systems, the newer the hardware, the less you will save by running this software. On newer systems CPU energy savings hover between 1-5%. Even then, the software is so light an unobtrusive, I would run it anyway.
Now imagine if large corporations with thousands of systems and servers ran this software. The savings would be substantial. Alas, those souls will have to pay for licenses. Home use, however, is free and has already saved me enough money to buy a Starbucks and/or multiple mp3's. Not bad for 30 seconds work. Get it here.