Abstract-System Level Description Languages (SLDL) emerged a decade ago for high-level System-on-Chip (SoC) design and efficient design space exploration. Initially performance and area constraints were the major concerns. Nowadays the shrinking of transistor size has brought power and temperature to top of the list of designer concerns. Although SLDLs are welldefined for functional and timing modeling, the dimension for power-and temperature-aware modeling is missing and needs to be added manually by the user in an ad-hoc fashion. In this paper we introduce; PowerMonitor as an Application Programming Interface (API) capable of (a) power annotation in the executable model, (b) power-aware simulation, and (c) monitoring and graphically representing power dissipation at the system level with flexible granularity and compositions.