Based on Internet and ZigBee wireless sensor networks, in this paper, we describe a novel power-monitoring system architecture that makes the mobile deployment of power-monitoring points quite easy and applicable to diverse power-monitoring targets. Specifically, we have designed a novel power-monitoring server (PMS) to serve as the operational core of the proposed architecture. The PMS can monitor, record, display, and manage the power consumption information of general equipment and power facilities. It can also actively detect if the power consumption is over a preset threshold and promptly send warning messages to power management personnel through mobile phone messages and e-mails. In addition, we have developed six types of wire or wireless portable power-monitoring devices (PMDs) that can be used to monitor a variety of targets, such as general equipment, traditional distribution boxes, and new distribution boxes with digital meters and can be deployed in different environments. Finally, a paradigm power-monitoring system has been constructed to monitor the power consumption of the campus at Chung Cheng Institute of Technology, National Defense University, to validate the feasibility and practicality of the proposed PMS architecture. The research results in this paper provide an effective solution to the problem that the existing PMSs may not be applicable to different environments and did not take diverse monitoring targets into consideration.