Potential-induced degradation (PID) is still one of the main reasons for unpredictable power losses in PV power plants. Volker Naumann, Nadine Schüler and Christian Hagendorf of Fraunhofer CSP and Freiberg Instruments present an approach for quick on-site PID testing of mounted PV modules, allowing PID diagnosis and prognosis of PID-related yield losses
The optimal and profitable operation of solar assets is become increasingly challenging as portfolio sizes increase. Stijn Stevens and Michael Matthes explore how device-level energy
forecasting is helping prioritise O&M activities across dispersed fleets.
Leading PV inverter manufacturer Huawei discusses recent technical developments to a better understanding of bifacial solar module PV power plants, using three recent case studies. These efficient PV modules need to be used with devices such as inverters to maximize value. Recently, many inverters and solutions that match bifacial modules have appeared in the industry. Which solution is the best match for bifacial modules? Based on a large amount of experimental data, this article describes the solution needed for bifacial modules.
Examining a PV power plant to ascertain its health is a key measure when
warranties for components expire. Romain Elsair and Marcos Blanco of Greensolver outline some
of the main steps involved in effective end of warranty inspections
In April an international working group will publish a bundle of
standardised contracts aimed at aiding the rollout of PV worldwide. Sara Verbruggen previews the
template contract for solar O&M and assesses its impact in streamlining this aspect of the business
With India going all out to achieve its target of 100GW of PV by the year 2022, the quality of
equipment used in installations is becoming increasingly important. Satish Pandey and Abhishek
Sharma of Mahindra Susten explore the role of on-site testing in quality control, based on the early
results from India’s first mobile PV lab
In a four-year project sponsored by the German Federal Ministry of Economics and
Energy, a consortium of German experts assessed the quality of actual PV power installations.
The researchers now report on how the effects of several common module failures on module and
string performance highlight the importance of consistent quality assurance to prevent risks to
Module failure | Defective modules causing power losses in PV systems need to be easily detected with a rapid and cost-effective inspection method. Researchers from Institute for Solar Energy. Research in Hamelin (ISFH) explain how UV fluorescence of module encapsulation polymers is used for the fast detection of module failures under daylight conditions without disconnection, allowing the inspection of up to 200 modules in an hour during daytime.
Operations and maintenance | India’s solar industry has been focused on reaching a hugely ambitious target of 100GW of PV by 2022. But as Tom Kenning reports, the need to get smart on managing and maintaining solar assets is now becoming an overriding priority
Forecasting | Predicting the power production of a PV plant offers a multitude of benefits to plant owners and grid operators. Jose Ruiz-Arias looks at the challenges of accurate forecasting across different timescales and in different climate zonesForecasting | Predicting the power production of a PV plant offers a multitude of benefits to plant owners and grid operators. Jose Ruiz-Arias looks at the challenges of accurate forecasting across different timescales and in different climate zones.
Data | The collection of inaccurate data at any point in the life cycle of a solar plant will undermine almost every aspect of the investment accounting. Mark Skidmore, Samantha Doshi, Matthia Heinze and Christos Monokroussos from TÜV Rheinland discuss the importance of precision data gathering in mitigating risk for builders, operators and financiers
System monitoring | The international standard guiding the monitoring of PV systems has been revised to include greater emphasis on accuracy. Will Beuttell of EKO Instruments explains some
of the key aspects of the revised standard and how it will help satisfy the maturing PV industry’s appetite for better quality data on plant performance.
O&M | Every photon and electron lost in a PV system represents unrealised revenue. The Solar Energy Research Institute of Singapore has developed a holistic diagnosis package – the PV System Doctor – to identify and cure underperforming PV power plants in real time. The team behind the service explains how it helps maintain a healthy PV system and ensure expected returns – or even surpass them
Wireless monitoring can offer your solar business real-time data with the lowest cost of ownership, explains Aeris.
Potential induced degradation (PID) of photovoltaic (PV) modules gets a lot of attention since 2010 when Solon published their findings about a degradation mechanism in their PV modules caused by high potential differences. When multiple PV modules are connected in series, a potential difference up to 1000 V or at some places even 1500 V is created between the cell and the grounded frame. This electrical field causes a leakage current and ion diffusion. PID is a multi-level degradation with causes and solutions at cell, module and system level.
A test campaign was conducted within the frame of a feasibility study for pidbull, a curing technology for PID developed by pidbull nv. 80 PV modules were characterized whereof 49 PV modules were stressed and cured for PID. The selected set of PV modules was composed of 49 different module types of 33 brands. The test was done according to the foil-method, as described by the standard in progress IEC 62804. However, to apply higher stressing and curing rates, the modules were tested with an aluminium foil inside a climate chamber for 96 hours. After the stress test, only 22% of the tested modules passed the 5% loss criteria as described by IEC 62804. In other words, 78% out of a set of today's most installed PV modules in Flanders are PID sensitive. Remarkable is that only 16 out of the 49 PV modules have less than 20% PID after the stress test. Additionally, a linear trend for PID reversibility was shown for modules with a stress level of less than 85%. The modules which lost more than 85% due to PID showed a lower recovery rate or in worst case didn’t recover at all.