Energy Performance Assessment and Baseline Development for Solar PV Systems through Energy Auditing

Accurate and standardized assessment of solar photovoltaic (PV) performance is critical for operational optimization, financial evaluation, and long-term degradation analysis. This study develops an energy auditing–based performance evaluation framework aligned with IEC 61724-1 and tailored to Indian climatic conditions. The proposed framework integrates a deterministic, physics-based baseline model with a data-driven, weather-normalized assessment approach to derive reliable Energy Performance Indicators (EnPI) and Energy Baselines (EnBl). Key performance metrics, including final yield, reference yield, performance ratio (PR), capacity factor, and specific yield, are systematically evaluated using standardized definitions. State-wise solar generation data obtained from the Central Electricity Authority (CEA) of India are analyzed for the period covering quarterly records from April–June 2024 and April–June 2025 to enable interannual and regional comparison. Weather normalization is applied to reduce the influence of irradiance variability, while statistical robustness is enhanced through multi-year comparison and uncertainty characterization based on distributional spread and central tendency analysis. A representative 1 MWp PV system example demonstrates that a PR baseline of approximately 0.75 corresponds to an expected annual energy generation of about 1.5 GWh under typical Indian irradiance conditions. National-level analysis indicates an overall increase of 19.20% in total solar generation between 2024 and 2025, with 20 states and union territories exhibiting improved performance. State-wise EnPI and EnBl comparisons reveal substantial regional variability in solar PV performance, attributable to differences in climatic conditions, installed capacity, and operational practices. The results confirm that the proposed hybrid baseline framework improves comparability across regions, minimizes year-to-year weather-induced bias, and provides a reproducible and standards-compliant basis for large-scale solar PV performance auditing and benchmarking in India.