The spatial distribution of renewable energy sources enables the development of self-sustainable microgrids capable of locally balancing renewable generation and electricity consumption. This paper analyzes the operating conditions of a hybrid power plant combining a photovoltaic (PV) system with a small closed-loop pumped hydro energy storage (PHES) plant, located near the town of Pirot in southeastern Serbia. Using site and topographic data, a hybrid configuration is defined to match the annual electricity consumption of the local distribution network. Hourly optimization is performed in PLEXOS through a two-step, medium-term/short-term approach, comparing a conventional fixed-speed synchronous machine with a variable-speed doubly-fed induction machine (DFIG), together with sensitivity scenarios on reservoir volume and pump power. Results show that introducing variable-speed operation has the most significant impact on system flexibility, increasing local consumption coverage by 10.21% and extending the longest continuous grid-independent operating period from 140 to 1,469 hours. The proposed methodology and results provide a basis for further dynamic performance analysis and control design of energy self-sustainable microgrids.