Services/Technical advisory

PV Performance Assessment
PV Performance Assessment at LuciSun provides an objective and technically robust evaluation of how photovoltaic assets perform in operation based on measured data. Its objective is to assess actual system behaviour under real operating conditions, identify and quantify performance deviations, and support performance verification, optimisation, and transactional decisions. The assessment delivers a clear and traceable understanding of operational performance, grounded in data quality control, consistent performance indicators, and quantified loss attribution, and complements Energy Yield Assessment by focusing on measured rather than modelled behaviour.

The PV Performance Assessment is based on the critical analysis of monitored data, typically including energy production, irradiance, meteorological measurements, availability records, and operational logs. A first and essential step consists in verifying the integrity and consistency of the available datasets and of the Data Acquisition System (DAQ). This includes the identification of missing data, sensor issues, communication gaps, and non-physical values, ensuring that subsequent analyses are based on reliable inputs.

Once data quality has been established, performance indicators are computed to characterise the behaviour of the system over time. These indicators are selected and interpreted with care, taking into account site conditions, operating regimes, and measurement limitations. Commonly used metrics include:

Key elements of the PV Energy Yield Assessment typically include:

  • Performance Ratio (PR) and related normalised indicators
  • Performance Index (PI), comparing measured production to expected behaviour
  • Performance to Peers (P2P) comparisons for relative benchmarking

Beyond high-level indicators, the core value of PV Performance Assessment lies in understanding the origin of performance deviations. Detailed Fault Detection and Diagnosis (FDD) analyses are carried out to identify and quantify specific sources of energy loss. This may include, for example, the impact of shading, soiling, degradation, inverter clipping, curtailment, or extended unavailability periods. The objective is to distinguish between measurement artefacts, modelling assumptions, and genuine system issues affecting production.

When relevant, performance analyses are used to support contractual milestones and acceptance processes. This includes the verification of performance criteria associated with the Provisional Acceptance Certificate (PAC) and the Final Acceptance Certificate (FAC), based on measured data and consistent performance indicators.

When performance is analysed over extended time periods, the assessment also addresses long-term behaviour. This includes the evaluation of seasonal effects, the identification of structural trends, and the estimation of degradation rates based on measured data, while accounting for inter-annual variability and changes in operating conditions.

The outcome of the PV Performance Assessment is a clear and technically justified understanding of how the asset performs in operation, supported by quantified performance losses and identified root causes. This information can be used to support acceptance tests, operational optimisation, corrective actions, or transactional decisions, and remains complementary to Energy Yield Assessment, which is based on modelling rather than on measured performance.