A successful embedded system design requires thorough domain analysis and design space exploration. The aim is to develop a target system, which implements the prescribed functionality and at the same time meets the design, time, and cost-related constraints. The early evaluation of design characteristics, such as power consumption, allows the user to take advantage of many architectural design options available and to modify the system architecture, if needed. Currently, SystemC is used to model the hardware and software parts of a system at the high level. However, the characteristics of the modeled system are obtained only at the late design stages during physical synthesis. Here, we present a framework for power estimation at the modeling level of a design using macromodels. The SystemC class library is modified and extended with new classes describing the computation of power characteristics of the behavioral-level hardware models.