This collection focuses on the latest advances and prospects for the optimal planning and operation of power systems with renewable energy sources (RESs), with nine original articles and one review article included. The nine original articles cover shared energy storage among multiple islanded microgrid systems, the decarbonization strategy for relatively isolated power systems, frequency response estimation for virtual power plants, an optimal scheduling strategy for distribution networks with mobile energy storage systems and PVs, the complementarity between offshore wind and other power generation sources, a two-stage modeling framework for peer-to-peer energy trading, a data-driven approach is employed to simulate unit bidding strategies in electricity market competition, a big data-based grid status analysis method for power systems with a high penetration rate of wind power, and a gas-electricity price linkage analysis method. The review article mainly presents the characteristics and challenges of flexibility markets in electricity distribution networks.