In the light of the growing importance of renewables and especially Variable Renewable Energy Sources (VRES) all over the world, policymakers and the industry need to address emerging issues to ensure continued growth of variable renewables and their successful integration in electricity systems. Renewable Energy Sources (RES) offer many benefits such as CO2 emissions mitigation, fossil fuels import requirement reduction and new jobs creation, just to name a few. At the same time, the recent expansion of variable renewables-based generation (wind and solar PV) also poses certain challenges, both technical and economic and they require short and long-term solutions. The report identifies these challenges and offers solutions drawing on the experience of the industry operators from around the world based on 32 country case studies covering five continents.