Introduction, current state of variable renewable energy (VRE) generation globally and in India; definition of VRE generation; variability and uncertainty associated with VREs; examples related to the impact of VREs on power systems operations; differences in grid integration with conventional and VRE generation, Various aspects of VRE such as sensing and measurement, forecasting, power electronics in grid integration, energy storage, conventional and upcoming analysis approaches and policies and regulations, Impact of VRE uncertainty and variability in power systems operations; impact of energy storage on grid integration; reliability concerns including system protection, inertia and ramping; must-run vs. at-par treatment with conventional generation resources; role of transmission expansion in VRE integration; improving grid reliability and resilience, Impact of increasing levels of electric vehicles; visibility and control concerns of distributed VRE generation; use of distributed VRE generation for providing grid services at multiple temporal and spatial scales, Overview of VRE forecasting and modelling for resource assessment, production cost simulation studies, and grid reliability assessment in both transmission and distribution systems, Latest advances in grid integration of VREs including use of artificial intelligence for forecasting in transmission and distribution systems; inter-sectoral modelling (e.g., transportation and-electricity sector modelling); cyber-physical systems modelling, Polices and regulations to support bulk-connected and distributed VRE generation from India and those found in countries with high VRE levels; different types of tariffs for renewable energy; case studies.