Monitoring power consumption for computers can be achieved through various methods, including hardware solutions like dedicated sensors or devices such as the "Watts up?" meter. For software options, Windows XP users can utilize the built-in Performance logs found in the Control Panel to track system activity, potentially including power consumption metrics. External tools like an ammeter are also recommended for measuring electric power usage directly. Personal experiences shared indicate that idle power consumption can vary significantly between systems, with one user noting their main computer uses 120 watts and another 130 watts, highlighting the importance of understanding individual power usage for efficiency.