In this era of modern technology, the cloud computing is considered as the most vibrant and indispensable part of the world of Information & Communication Technologies which is shaping the modern networking technology by introducing a new door with technical experiments for conserving the environment. It is empowered to rise the energy efficiency by reducing the carbon emissions that leads the transformation of cloud computing into green cloud computing. The buzzword term “Green cloud” is the combination of two terms “green” and “cloud” to symbolized the concept of ecofriendly environment with the Internet that is basically known as cloud computing. Even though the immense power of modern technology already gripped the environment and destroying the nature and environment that is not a renewable resource and it obvious has a great impact on life. Therefore it rises the awareness regarding environmental impact of the computing and so that green technology is gaining the importance accordingly. In this survey paper, we define a systematic approach to analyse different data centres’ energy efficiency along with the concepts of diminishing the cost of the data centres by utilizing the cooling systems efficiently.