The Most Efficient and Adaptable Solution Design for Bifacial Modules

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.

End of warranty inspections in solar PV power plants

By Romain Elsair; Marcos Blanco

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

Towards a standardised contract for solar O&M

By Sara Verbruggen

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

Mobile PV testing in India

By Satish Pandey

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

Failure assessments of PV systems demonstrate the importance of elective quality assurance

By Dipl. Ing. Annett Sepanski; Dipl. Ing. Uwe Hupach; Dipl. Ing. Willi Vaaßen; Dipl. Phys. Jörg Schmauder; Prof. Dr. Ansgar Steland; Thomas C. Sauer heads; Dipl. soc.sc., Dipl. ec. Georg Fischer; Dr. Andreas Sommer; M.Sc. E. Sovetkin

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 financial success

Detecting cell cracks and other PV module failures with UV fluorescence

By Arnaud Morlier, Arnaud Morlier received B.S. and M.S. degrees in chemistry from the University of Nice Sophia-Antipolis in 2006 and 2008 and a PhD in physical chemistry from the University Joseph Fourier, Grenoble, France in 2011.; Michael Siebert, Michael Siebert achieved a B.Sc. in mechatronics from the University of Applied Sciences Ostwestfalen-Lippe in 2009.; Marc Köntges, Marc Köntges received his PhD degree in physics 2002 at the University of Oldenburg on characterisation of CuInGaSe2 and CdTe thin film solar cells.; Iris Kunze, Iris Kunze achieved her training as chemical technical assistant at the Hannover School for chemistry and pharmacy.; Susanne Blankemeyer, Susanne Blankemeyer was with Krane-Optik, Rheda-Wiedenbrück, Germany, until 1986, where she was trained as an Optician. From 1999 to 2007, she was a Laboratory Assistant with the R&D Department of Orbotech, a manufacturer of automated optical inspection systems, in Bad Pyrmont, Germany.; Gerhard Mathiak, Gerhard Mathiak studied physics at Technical University Braunschweig and has a PhD in engineering from Technical University Berlin.

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.

Digital O&M opportunities in a water-scarce India

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

Towards accurate PV power forecasting

By José A Ruiz-Arias, José A Ruiz-Arias is weather and solar radiation expert in Solargis. He provides support to clients and develops models to assess and forecast solar radiation.

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.

Solar life-cycle management: Is the spectre of lost returns holding solar energy back?

By Mark Skidmore, Mark Skidmore has over 14 years’ experience in the solar industry, and over 18 years’ experience in the construction contracting industry.; Samantha Doshi, Samantha Doshi has over five years’ experience in the areas of PV module certification, laboratory module and component testing, and field performance and failure analysis.; Matthias Heinze, Matthias Heinze is the director of business development at TÜV Rheinland, and has several decades’ experience in the areas of PV plant qualification and monitoring, laboratory module and component testing, performance measurement and failure analysis.; Christos Monokroussos, Christos Monokroussos received his doctorate in photovoltaics from Loughborough University, UK, and has 10 years’ experience in PV research.

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

IEC 61724-1: what’s it all about?

By William Beuttell, William Beuttell has been an application engineer for EKO Instruments for two years. Prior to that was an application engineer with Campbell Scientific. He is focused on R&D as well as software development efforts for EKO Instruments especially in the USA, as well as providing technical support to the EKO Instruments customers in North America. His interests include developing new sensors for improving aerosol monitoring networks as well as developing software to add value to the current EKO instruments product line.

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.

The ‘PV System Doctor’ – smart diagnosis for photovoltaic systems

By Dr Mridul Sakhuja, Dr Mridul Sakhuja received his PhD in electrical and computer engineering from National University of Singapore (NUS) in 2014. Since then, he has been working as a research fellow at SERIS.; Zhang Yin, Zhang Yin received his master degree in electrical and computer engineering from NUS. Since 2016, he has been working as a research associate SERIS. His research focus is development of PV system fault detection by imaging analysis.; Dr Lim Fang Jeng, Dr Lim Fang Jeng received his PhD in electrical and computer engineering from NUS in 2015. Since then he has been working as a research fellow at SERIS, NUS. His research focus is on the design and development of high performing PV systems including smart monitoring systems, cross-climatic PV systems and system failure diagnostic techniques.; Parvathy K. Krishnakumari, Parvathy K. Krishnakumari received her M. Tech degree in energy management and climate technology from Jain University, India in 2014. Since 2015 she has been working as a research assistant at SERIS. Her research focus is on data visualisation and modelling of PV data.; Tan Congyi, Tan Congyi received his B. Eng. degree in electrical engineering from NUS in 2014. Since 2015 he has been working as a senior engineer at SERIS. His research focus is on development of testing and commissioning methodologies for PV systems.; Dr Stephen Tay, Dr Stephen Tay received his PhD in materials engineering from Imperial College London in 2015. He joined SERIS after that and is now head of the institute’s National Solarisation Centre.; Monika Bieri, Monika Bieri received her Chartered Financial Analyst (CFA) diploma in 2003, followed by the executive programme in advanced studies in renewable energy management from the University of St. Gallen in 2013. She has 14 years of experience as a financial analyst. Since 2014, she has been working with SERIS.; Dr Zhao Lu, Dr Zhao Lu received his PhD in electrical and electronics engineering (photovoltaics) from Katholieke Universiteit Leuven, Belgium in 2011. Since 2014, he has been working as a senior research fellow and then as head of the photovoltaic systems technology group at SERIS; James Ha, James Ha received his bachelor degree in photovoltaics and solar energy from the University of New South Wales, Australia, in 2004. Since then he has worked with TUV Rheinland in multiple locations.; Eddy Blokken, Eddy Blokken received his master degree in industrial management from Katholieke Universiteit Leuven, Belgium in 1993. Since then he has worked as business development manager in multiple locations.; Dr Thomas Reindl, Dr Thomas Reindl is the deputy CEO of SERIS and principal research fellow at NUS. He started with PV in 1992 at the SIEMENS Corporate R&D Labs. After holding several management positions at SIEMENS and running one of the leading German PV systems integration companies as chief operating officer, he joined SERIS in 2010 and became director of the Solar Energy Systems cluster.

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

Potential induced degradation (PID): a test campaign at module level

By J. Carolus, Hasselt University and imec vzw; M. Daenen, Hasselt University and imec vzw

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.

Preventive O&M - Maximising PV plant availability

By Arnoud Klaren, Arnoud Klaren is Foresight’s senior portfolio manager and technical director for UK and Spain. He joined Foresight in 2011 from SolFocus, where he spent four years managing solar projects in Spain, Saudi Arabia and Greece based on concentrated PV technology. Prior to SolFocus he founded and managed ThinkSpectrally, a spin-off company of the University of Valencia in Spain, dedicated to quality assurance in PV manufacturing.

Asset management | As one of the biggest utility PV owners in the UK, Foresight has extensive experience of getting the most out of operational solar plants. Its technical director Arnoud Klaren draws on some of the lessons the company has learned from minimising the risks that affect solar projects over their lifetime.

New approaches to solar O&M in China

By Karl Hong Wan, Karl Hong Wan attended the graduate school of Southeast University in China, majoring in electrical engineering, power system measurement and intelligent instruments. He has been engaged in the design, construction and operation of power substations, power plants and renewable energy generation for 30 years. He currently works in the design and research institute of GCL New Energy

Operations & maintenance | Proposals by Chinese authorities to scale back the subsidies available for grid-tied PV will require new efforts to maximise the performance of power plants. Karl Hong Wan of the GCL Design & Research Institute explores some of the innovations in O&M practices that will help China’s solar industry cope with decreasing financial support.