This 2023 Edition of the IEEE International Network Generations Roadmap (INGR) updates the already very comprehensive chapter dedicated to Energy Efficiency, which builds upon the initial white paper released in April 2020[1] with subsequent annual updates to the roadmap (available from IEEE). For this purpose, the Energy Efficiency Working Group developed an analysis of the energy efficiency constraints across the whole ecosystem of the Fifth Generation '5G' and following network infrastructure, which can be leveraged by all stakeholders to prioritize resource allocation and technology development to ensure that both technical and economic forecasts can be met. The complexity of the ecosystem and the traditionally siloed approach within the industry has often prevented the adoption of a holistic approach to addressing the fundamental problem of energy, which is the ultimate constraint to any complex deployment. The proposed framework facilitates an assessment of bottlenecks and their implication on the network. It may be used by both academic and industry stakeholders to develop solutions that address the real issues and enable a healthy ecosystem. After a comprehensive survey of the ecosystem and its challenges, the following key areas were selected for a more in-depth analysis: ▪Network Efficiency ▪Small Cell Migration ▪Base Station Power ▪Economic Factors ▪Grid / Utility This chapter also identifies the need for a comprehensive 'Systems-of-Systems' (SoS) analysis to address the complex inter-relationships among the multiple layers, which the infrastructure leverages. An initial proposal describes how a model can be built to enable a comprehensive assessment of energy requirements across such a diverse ecosystem. A future step in the process will consolidate a proposal for standardization of this model, which can be utilized by all stakeholders for both analysis and forecasting of capabilities and return on investment. Being green is also green ($$$)!