Comparative analysis of the variability of fixed and tracking photovoltaic systems

• Variability analysis of fixed-tilt and tracking PV systems is conducted.
• All systems are located at the same location and all data is time synchronised.
• Tracking systems were found to be more variable than fixed-tilt systems.
• Variability difference between fixed-tilt and dual-axis governed by sun position.

Growing penetrations of PV generation in electrical networks pose new challenges for electricity industry operation and planning. Characterising the variability of PV generation can assist in these tasks. This paper presents a comparative short-term (5 min) variability analysis for fixed-tilt, single-axis tracking, dual-axis tracking and concentrator PV systems using time-synchronised data from The Desert Knowledge Australia Solar Centre (DKASC) in Alice Springs, Australia. A number of analysis and data presentation techniques are presented to assess different aspects of this variability over the course of the day, and across different seasons. Results highlight the very different variability characteristics of fixed tilt and tracking PV systems, and hence the importance of differentiating between different PV system types when analysing their potential operational impacts on the electricity grid.