Solar energy is becoming an increasingly popular option for households looking to reduce electricity costs. This study examines the impact of a residential solar power system installed in a household in Vojvodina, Serbia. The system has a capacity of 11 kW and operates without battery storage, feeding excess energy into the grid. The analysis is based on actual electricity consumption, production data from the inverter, and electricity bills for 2024. The results show that the solar system led to a major reduction in electricity expenses. The household used a total of 17,816 kWh during the year, with 13,451 kWh produced by the solar panels. Out of this, 3,232 kWh was used directly, while the rest was sent to the grid. Without the solar system, the total electricity cost would have been around 1,954 euros. With the system in place, the household paid only 751 euros, leading to significant savings. These findings suggest that installing solar panels can be a good long-term investment, helping households lower their electricity costs while also contributing to a more stable and sustainable energy supply. Wider adoption of such systems in Serbia could reduce reliance on traditional energy sources and improve energy efficiency at the household level.