The IEEE-published research addressed challenges from increasing PV-plant integration and grid instability linked to atmospheric conditions. It examined how improved monitoring generated large data volumes that required efficient handling. It described a procedure for storing synchronized measurements from PMUs and DAQ-based ePMUs. It outlined a communication and storage setup aligned with IEEE C37.118.2 and evaluated under IEC 61850-90-5 criteria. It explained the storage choice using data-volume and accessibility analysis. It validated the procedure and ePMUs through field tests at two grid-connected PV plants. It confirmed suitability for quasi-real-time use over LAN and WAN. It noted that millisecond-level synchronization enabled seamless offline analysis of recorded data.