Energy storage systems integration with large-scale PV power plants, named Intelligent PV power plant (IPV), could contribute to improve the viability of these plants and to provide ancillary services to the main grid. The number and extension of the provided services depend not only on the size of the storage system, but also on the manner how this storage system is managed. In this paper the market participation based on different firming control strategies of an IPV power plant is proposed to optimize the economic exploitation based on the storage system management considering PV generation predictions. The most appropriate firming control strategy is selected to participate on the daily market which is strengthened with an online model predictive control (MPC) to compensate the PV prediction errors participating in the intraday market. The real operation of the Iberian Peninsula market integration is also explained and developed. The development of this management strategy considers as a case study a real IPV plant located in Tudela (Navarre, Spain) and owned by Acciona Energía, which included a Lithium-ion based energy storage system from 2012 to 2013 in the framework of a European project.