Renewable energy and energy efficiency are two of the main objectives underpinning the development of the energy sector in the Republic of Moldova. They aim at capitalizing on renewable energy sources in the current context of energy security, energy market liberalization, demographic expansion and environmental pollution. In the present scientific approach, we intend to investigate the legal instruments that reflect the importance and role of renewable energy sources in the process of refining the most important guidelines of international legal regulations in the field, a time that has been extensively studied in the legal doctrine. Also, studying the legal principles that enhance the role of alternative energy sources in the context of technology development must be necessary, as they characterize the essence of all legislation in the energy sector, the values promoted and protected by it, the finality, the consequences and , not least, determines the directions and strategies for the development of alternative energy sources. The scientific research, which includes the general and special approaches of analysis, was carried out with the following methods: analytical, logical, historical, comparative, deductive and legal. The novelty and originality of the researched theme is to improve the analysis of the use of renewable energy sources in the context of the development of the energy field at national level. The problem of correlating all these key elements has led us to an analysis of the principles of the operation and application of renewable energy sources. It is in itself a process of legalization, a process of discussion, analysis, synthesis, research, and debate.