Objectives

The goal of the project is to identify, quantify and reduce uncertainties associated with key performance metrics 
(Performance ratio (PR) and Performance loss rate (PLR)) of PV systems, and provide the underpinning tools 
that facilitate uptake and continued improvements beyond the timeframe of this project. The specific objectives are:

1.    To develop a new draft specification for the classification of reference devices for PV systems (equivalent to ISO 9060 for pyranometers). In addition, to develop accompanying metrology capabilities for accurate characterisation and SI-traceable calibration of reference devices (i.e. irradiance sensors with integrated electronics), including linearity, temperature dependence, spectral responsivity and angular responsivity measurements. (WP1)

2.    To develop models for the propagation of measurement uncertainty in PV systems from sensors to performance indicators, such as the performance ratio defined in IEC 61724-1:2021, primary quantities (irradiance, output power), and auxiliary quantities (e.g. ambient temperature and wind speed, clear sky index etc). To then write good practice guidelines for the accurate, and cost-efficient monitoring of PV systems (bifacial, single-axis tracker and commercial-rooftop) based on the optimisation of sensor selection and placement. (WP2)

3.    To develop harmonised and validated methods and sampling strategies to determine the performance loss rate (PLR) of PV systems over time based on the quantification of degradation rates in PV systems. In addition to consider combinations of system-level monitoring data and in-field module characterisation and testing to improve PLR data accuracy. Indicative uncertainty budgets for common and proposed measurement scenarios will be derived. (WP3)

4.    To develop reference PV systems by combining metrology grade instrumentation with commercial instrumentation that meet the requirements of IEC 61724-1 and to use these to provide time series reference PV system performance data with quantified measurement uncertainties that are available to users via an open access database. In addition to generate validated digital twin models for the reference PV systems and to use these models to produce time-series data for optimising system and sensor data accuracy. (WP4)

5.    To facilitate uptake of the technology and measurement infrastructure developed in the project by the measurement supply chain (instrument manufacturers, accredited calibration and measurement laboratories), standards developing organisations (IEC TC82, IEA PVPS, PVQAT), and end users (e.g. PV system manufacturers). (WP5)