This paper discusses the assessment of integrating photovoltaic-battery hybrid power plants into the electrical grids of the Azores islands and their ability to comply with advanced network services. To ensure the hybrid power plant supports the grid operational requirements, a methodology was devised through steady-state and dynamic numerical simulations. On one hand, the steady-state analysis generated active-reactive power diagrams for different voltage levels at the plant's interconnection point with the island's grid, demonstrating that the internal grid of the PV-battery hybrid power plant allows a significant range of reactive power modulation in different operating conditions. On the other hand, dynamic analysis highlighted the plant's crucial role in modulating reactive current production during grid faults. Additionally, it showed the plant's capability to automatically reduce active power injection during over-frequency events and, as a result, lessening the frequency regulation effort for synchronous generators and fast energy storage system.