The integration of photovoltaic (PV) systems with the grid is undoubtedly an issue of great interest both in terms of energy production, but also as a support to the grid as an ancillary service, but to evaluate the performance of the use of PV in an unconventional way, it is necessary to have reference models to be applied to evaluate the characteristics and integration requirements. In this work, an ancillary service provided by a grid-connected PV is shown and a hardware in the loop simulation environment is created to simulate performances and integration issues.