This research project raises the fundamental issues related to the operation and services that large scale PV power plants with energy storage are able to offer to the electrical grid, although the conclusions may also be applicable to smaller systems. Based on the exploration of the services that a PV system with energy storage can provide the network, this project will study and analyze the most suitable power processing and distribution systems for PV plants, the most promising energy storage technologies, together with their monitoring and management systems, and the hierarchical and distributed control systems suitable for such power plants. From the knowledge acquired about the different elements that integrates the PV system, this project addresses the investigation of grid support and power control strategies which are oriented to improve the integration of PV plants with energy storage in the network. In the last part of the project, the resulting proposals emerging from the analysis performed previously will be validated and tested in virtual prototypes and demonstrative PV plants.