The increasing integration of renewable energy sources, particularly solar power, introduces variability that poses significant challenges to power system reliability. This research addresses the management of solar generation uncertainty in a distribution system using real data from the E.W. Brown Universal Solar Facility and electricity demand (load) data in Kentucky, U.S.A. The objective is to determine the amount of reserves to mitigate operational risks and maintain system stability under different uncertainty scenarios. We simulate the expected dispatch over 24 h by solving a multi-period, stochastic, security-constrained DC optimal power flow (SCOPF) using the MATPOWER Optimal Scheduling Tool (MOST). Unlike traditional unit commitment models, we assume all generators remain continuously active throughout the dispatch horizon. To highlight the role of reserves, we compare four different operational cases. The results underscore the importance of reserves as a fundamental tool for managing renewable energy variability and ensuring dispatch reliability, denoting that optimal dispatch must balance supplying demand, maintaining sufficient reserves to handle uncertainties, and minimizing operational and financial risks.