There are several initiatives worldwide to deploy SMs (SM). SM systems offer services aimed at achieving many goals beyond metering electricity consumption of households. Despite the advantages gained by SMs, there are serious issues that may lead to the system's inability to reach its goals. One obstacle, which can lead to social rejection of SMs, is perceived security and privacy violations of consumers' information. This poses a significant threat to a successful rollout and operation of the system as consumers represent a cornerstone in the fulfillment of goals such as energy efficiency and savings, by their active interaction with SMs. To investigate consumers' perception of SMs, theories and models from the technology acceptance literature can be used for understanding consumers' behaviors, and exploring possible factors that can have a significant impact on consumers' acceptance and usage of a SM. In this paper, a hybrid and extended model of a two well-known technology acceptance theories is presented. These theories are: the Unified Theory of Acceptance and Usage of Technology- UTAUT, and Innovation Diffusion Theory- IDT. The hybrid model is further extended with acceptance determinants derived from the Smart metering case in the Dutch context. The model aims to investigate determinants that can shed light on consumers' perception and acceptance of SM.