5G Network strongly depend upon ultra dense integrated small cell beside macro cell. This kind of UDN consists of large number of macro cell and small cells through which increase in energy demands can be met. Practically energy consumption is done by dynamically controlling modes in radio networks. This paper reflects the significant power saving by considering only a subset of network node which reduce traffic migration and control phase signaling. To enable the sustainable UDGN improve system energy efficiency, and alternative energy source are introduce to reduce dependence on traditional fossil fuels. In 5G optimizing energy is the most important challenge and maintenance of RF communication system. RF energy harvesting is a unique technique for 5G system as an alternative to traditional energy supply sources. Future evolution of the networks has also been assumed to open many new business horizons for the operators and the need of not only a resource efficient but also an energy efficient ecosystem has greatly been felt. The deployment of small cells has been envisioned as a promising answer for handling the massive heterogeneous traffic, but the adverse economic and environmental impacts cannot be neglected.