vRE forecasting is one of the crucial initiatives to support the effective grid integration in the context of energy transition in Indonesia. This would contribute to more safe and economic operation of the power system. GIZ is working on a demonstration project to introduce a scientific operational vRE forecasting system in Indonesia. vRE forecasting model is being implemented for Solar in Jamali system and Wind in Sulawesi system. In the initial phase, the major power plants that are focused are 143 MWp Cirata Solar PV park, 25 MWp Kubu plant and 75 MWp Sidrap farm. The methods of Numerical Weather Prediction based day-ahead predictions , satellite imagery based intra-day predictions and combination techniques are utilized to come up with accurate forecasting methods. The vRE forecasting model results are benchmarked with measured data to provide insights on the model improvements. This is one of the first attempts on step-by-step scientific vRE forecasting in Indonesia and is expected to contribute crucial insights for the utility (PLN).