Looking forward, the development of storage technologies and the development of international interconnections are foreseen to further facilitate the integration of wind and solar power. In these situations, balancing the power system during periods of low load will necessitate further adaptations to maintain the physical parameters of the network. An ongoing IEA work within the Grid Integration of Variable Renewables project (GIVAR) analyses these options in more detail. Hence, it will be necessary in the next 20 years to keep some conventional power plants online to provide ancillary services and ramp-up capabilities.