Check power consumption of individual hardware components
I can check the total average power consumption of my machine using powerstat. However how do I check the power consumption of the individual components of my computer, like say the wlan-card?
Since the individual-component-power-usage monitoring circuitry is not designed into modern computers, you're left with:
Monitor system power usage with the device connected.
Monitor system power usage with the device disconnected.
Some devices (CPU, RAM, hardware buses, etc) can't be measured with this technique.