This paper describes the application of wireless sensor network to monitor and control electrical loads in residential areas, mainly heating and cooling loads, which accounts for around 50% of the residential electricity consumption. In this way, a control algorithm has also been implemented in order to select the optimum load control strategy according to a target demand profile and a set of prefixed constraints, allowing the customers to modify their power demand with minimum comfort levels. Therefore, this application offers the residential customers a flexible, powerful and low-cost tool to manage their electrical loads, avoiding any additional wiring and extending the wireless sensor network technology to small customers, with around 30% share of the global electricity consumption. This system has been implemented in a university environment, and the results are also included in this paper.