Rapid system modelling and early evaluation of design characterisation are central to design space exploration. SystemC is used widely for system-level modelling, but it lacks the semantics to capture power consumption. The article presents a novel high-level power estimation methodology based on SystemC and aspect-oriented programming (AOP). Using a composite pattern, our methodology is applicable to the power estimation of a complex system. The proposed strategies support macro-models with multiple features. The experimental results are illustrated with case studies.