Energy resources are essential to nearly all major challenges and opportunities the world faces today: be it for jobs, security, climate change, food production or income increase. Sustainable energy is important for strengthening economies, protecting ecosystems and achieving growth. The new pattern of economic development should be based on the concept of "green economy" which focuses primarily on the interplay between environment and economy. Since the latter heavily relies on the new approaches to the consumption of energy, the new economic model implies the switch to the "green energy". The study aims to provide fact-based comprehensive analysis of the main directions of "green energy" and energy efficiency in the BRICS. The countries in question are in the list of the world's top energy consumers and producers, as well as the largest emitters of CO₂. By particularly focusing on the OECD's definition of "green energy" the authors provide a systematic view of the current energy landscape, the volumes and directions of renewable energy investment, the mechanisms for GHG emission's reduction, the overall energy efficiency of the BRICS economies. The paper regards the best practices of the countries in question in terms of using and regulating renewable energy policy. The analysis of energy efficiency indicators (calculated using the World Energy Council methodology) showed that the best results are obtained by Brazil. This is associated with high share of "green energy" in the energy balance, as well as with effective state programs in this area. The authors identify the main trends in the "green energy" development and give recommendations to improve the energy efficiency of the BRICS countries. The main measures can be divided into three groups: de-carbonization of energy generation; innovations in the field of energy technologies; creation of market conditions for attracting private investors, as well as public funding of relevant programs in "green energy" sectors. The mutual cooperation of the BRICS countries in the field of "green energy" has great potential and can be useful for the policy-makers in the other emerging economies for creation of energy efficient lifestyle.