well for reducing the power consumption while the computer is running, proportional to the load it's under, is either - automatic via speed regulation, or if not, there's an applet I believe called "cpufreq" that can be added and resides in tray.
#Power Saving on Mint
celest cradle
In addition, there's a program called TLP, which in conjuction with TLP UI gives a GUI to adjust power and performance levels of components to a high degree.
Lastly, Linux Mint's "Power" Settings control stuff like when should the screen suspend on idle, and if and when the whole computer should suspend, or hibernate (if a big swap file = installed memory is available for this), or to shut down on idle.