It is evident that developed economies have made significant progress in terms of renewable energy due to their early advancements. In contrast, emerging economies are falling behind in this aspect. While there has been some catching up by emerging economies in the last decade, there is still a considerable distance for them to cover. Our analysis mainly focuses on calculation of renewable energy efficiency in developed as well as in emerging economies using Stochastic Frontier Analysis or SFA, which supports the above conclusions and underscores the need for further developments. This work also introduces a non-parametric model to check for the relationship between sustainability and renewable energy efficiency. How this efficiency impacts sustainability through non-parametric estimation known as Local Linear Dummy Variable Estimation, and obtained positive results indicating a pressing need for the development of renewable energy—a contribution that will lead towards greater sustainability efforts.