The electricity grid is undergoing a major renovation and becoming a smart grid by integrating the advances in Information and Communication Technologies (ICT). Current applications in energy generation, power distribution and its consumption need improvement in several ways, such as, making efficient use of green energy, increasing automation in distribution and enabling residential energy management. The existing grid does not provide sufficient mechanisms to manage the residential electricity consumption. However, interconnecting consumer devices with the home area networks, and at the same time, communicating with the utility networks through a home gateway facilitate residential energy management in smart grids. Residential energy management uses utility-driven price signals which vary depending on the time of the day. This is called as Time Of Use (TOU) pricing. In TOU pricing, electricity consumption during peak hours costs more than electricity consumption during off-peak hours. TOU prices reflect the variation in the actual cost of power during one day. Utilities run bas plants to supply power for the base load. In peak hours, demands of the consumers rise, and utilities bring peaker plants online to supply additional power. Peaker plants have higher operating costs and higher GreenHouse Gas (GHG) emission rates than base plants. Therefore, reducing peak load decreases the expenses for energy generation and it decreases the GHG emissions. Wireless sensor networks can play a key role in reducing the demand of the consumers in peak hours. In this paper, we employ TOU-aware energy management in a smart home with wireless sensor home area network and analyze the impact of this schemes on the peak load. We show that our scheme decreases the use of the appliances in peak hours and reduces the energy bills for consumers.