In a traditional electrical grid system, the main causes of power inefficiency are high-voltage, long-distance transmission, and large-scale centralized electricity generation. To overcome these challenges, the idea of smart grids has been introduced to enhance the power efficiency and reliability of the electrical grid by exploiting green wireless communications. The crucial characteristics of a smart grid associated with the green wireless communications are demand response (DR), demand-side management (DSM), renewable powered base stations (BSs), green wireless sensor networks (WSNs), and Internet of Things (IoT) for smart cities. Indeed, wireless communication technologies will play a key role in the revolution of smart grids by communicating a variety of data and measurement among power generators, transmission lines, distribution substations, and consumer loads. In this chapter, designing energy-efficient communication infrastructures without adversely affecting the capacity and QoS is one of the main concerns.