The paper considers the use of renewable energy sources, the economic efficiency of their full-scale implementation, the policies of European countries on the development of energy systems and domestic energy networks. Existing energy networks in most cases do not meet modern market requirements. First, it concerns energy supply based on the renewable energy sources as most of the electricity is supplied to the electric networks in a decentralized way and only then to the consumers. Therefore, the key tool for successful energy redistribution should be the expansion of powerful regional transmission networks and local distribution networks. At the same time, consumption and conventional energy generation should become more flexible to meet market requirements. The use of “smart technologies”, especially digitalization with the help of smart energy meters, should be the driving tool to create new economic opportunities and simplify the coordination of energy generation and consumption. The use of “smart technologies” for renewable energy should be the basis for the energy systems development in Ukraine. International practices indicate the effectiveness of these technologies. The main advantage of their implementation is the security of energy supply to consumers, which significantly reduces carbon dioxide emissions as well as technological energy losses in the electric grid. One more advantage is the optimization of existing energy systems and their intelligent automation that allows the efficient use of renewable energy sources, reduction of the transmission losses through networks, the increase of the stability level of electricity supplies, the reduction of the negative impact of energy systems on the environment and meeting consumers’ needs for reliable energy supply.