Consumer electronic device control is one of the key challenges in smart cities development. This paper introduces the design and hardware implementation of smart energy management systems to be applied for Bahrain smart cities development. The system is capable of monitoring the energy consumed by the appliances, and accordingly limits the overall consumption not to exceed a certain stated threshold. Therefore, the user gets foreknowledge of their own energy consumption before getting the official electricity bill. The design implementation based on using Arduino UNO micro-controller, and ACS712 current sensor which measures the alternating current (AC) drawn by an appliance, and XBee transceiver which provides wireless communication with the coordinator node. The design was tested on real testbed, as the results showed that the power consumption drop down reached about 20%.