Having a power efficient system can save you money, so it could be a good idea to generate a power efficiency diagnostics report, here’s how! 
Power Diagnostics Report is an excellent feature of Windows that shows you how much power your system is consuming. It shows the diagnostics report that analyzes your system for battery problems, and energy efficiency and highlight any known issues to you. Here is how you can do it:
1. StepYou need to run the commands in CMD in Administrative mode. Search for cmd in the Windows 8 search panel. Right click cmd and select Run as administrator from the bottom:
2. StepNow type in the following command:
powercfg -energy -output %USERPROFILE%\Desktop\Energy_Report
3. StepOpen up the file on Desktop. Right click on the file and open it with Internet Explorer. Here is how mine looks like:
Have a look at the entire report and see the red highlighted areas. Work upon the suggestions shown in the document so that you can better utilize your computer performance while you are working.