National Institute for Research and Development in Electrical Engineering ICPE-CA


Laboratory of Photovoltaic Systems


It is addressed to owners and managers of photovoltaic parks as well as to maintenance service contractors for photovoltaic parks:
1. Diagnosis Services for Potential Induced Deterioration (PID) of the photovoltaic modules in-situ;
2. Diagnosis Services for any kind of power loss in the photovoltaic parks in-situ;
3. Determination of the Performance Ratio PR of the photovoltaic parks and the permanent or temporary monitoring of its evolution for an early detection of the power efficiency deterioration and prevent failure of the components.
4. Measuring the panels power, measuring current-voltage characteristic of the panels and or a certain area of photovoltaic panels on site, electro-luminescence testing (El Tester) of the photovoltaic park on site in accordance with the European and national standards;
5. Measuring the invertors efficiency and the quality of the electricity generated by invertors on site, in accordance with the European and national standards;
6. Laboratory measuring of the current-voltage characteristic, of the photovoltaic panels power with accuracy of 0,5% in the standard terms of reference and according to the European and national standards.

1. PID - Potential Induced Deterioration is an effect which was discovered few years ago, affecting over 30% of all PV modules installed worldwide and consisting of the significant reduction of the affected PV panels power that can reach up to 10-20% of the nominal power in a few weeks. The phenomenon is favored by moist heat (temperatures above 45 deg. Celsius on modules and humidity over 60%) and it is caused by the residual air streams arising between the Al frames and poles of the PV panels (through the glass and the wrapping material) at the panels row ends where the potential difference can reach hundreds of volts. This phenomenon is reversible and the recovery time is much lower as PID is found in time. In Romania it was firstly detected in a photovoltaic park near Giurgiu and it is currently reported as increasingly.
2. Analyzing the current-voltage characteristic, the cause/causes of the power losses can be detected, so as the corrective measures can be decided.
3. The evolution of the Performance Rate PR in sense of greater decrease than the one generated by the normal rate of panels degradation indicates an anomaly whose cause must be found in order to remedy it before the failure of some components.
4. For inverters we have instrumentation that can determine their efficiency, the power quality (harmonics measurement) and the point MPPT efficiency.