The 5G wireless cellular networks are evolving, to meet the drastic subscriber demands in near future. This is accompanied with a rise in the energy consumption in cellular networks. Higher energy consumption result in a rise in the carbon dioxide emissions into the environment, and exposure to greater amount of harmful radiations. To indemnify the ecological and health concerns associated with the rise in CO2 levels, an important technology is GREEN communication. This paper presents a survey on various energy-efficient scenarios for green communication, involving device-to-device (D2D) communication, spectrum sharing, ultra-dense networks (UDNs), massive MIMO, millimeter wave networks and the Internet of Things (IoT). For improving the battery lifetime of user terminals in a network, a three-layer architecture is proposed, which emphasizes on transmitting information through relays, between a given pair of users. The susceptibility of security attack on relays is also enumerated. As security in the networks cannot be overlooked, secure power optimization is studied, and the possible security attack on users within the small cell access point (SCA) of the 5G networks is proposed. Some of the key research challenges in association to green communication and security have been discussed, and the ongoing projects and standardization activities also stated in the paper.