Drive Power State

While it can be argued that using a green hard drive makes little difference to the kilowatts you can save in a year, let us not forget that every contribution counts. In case you are interested in the power consumption of your hard drives along with the frequency they are powered on and off then you might consider using specialized tools, such as Drive Power State.

Displays all local and external drives connected

Since the application is portable, it means it does not require installation or configuration, but rather you can decompress the archive in any desired location on your hard drive. On a side note, although the drive you launch it from is irrelevant, it is recommended that you open it with Administrator privileges.
As soon as you run the program, the drives connected should be detected automatically. Moreover, if you add and remove Flash stick, external drives or SSDs, they should be displayed and dropped from the list in the interface based on the refresh rate you configured.

Provides you the IDs and serial numbers of the HDDs

The idea behind the utility is to provide you with an easy solution to monitor the basic power consumption of the hard drives. For convenience purposes, the tool enables you to keep a continuous log that contains the events your are watching.
As you probably assumed, the application needs to be running in order to register this type of data. However, it is light on resource consumption and non-intrusive, since you can minimize it to System Tray.
Besides the power, idle time and duty cycles when they are power down automatically by Windows, the program also reveals information that can come in handy, such as the serial number, the mount points for each drive or the volume IDs, for instance.

A utility for monitoring the power spent by your drives

All things considered, Drive Power State does not only help you retrieve valuable information like the drives' serial numbers and IDs, but it also enables you to keep a close eye on the total power consumption and duty cycles associated.