Cloudbusting

Forecasting | Short-term PV forecasting offers a multitude of benefits, from trading on wholesale power markets to improved plant operation. Sara Verbruggen reports on some of new the technologies driving forward improvements in the accuracy of forecasting techniques.

Module tech under the microscope

It’s always nice when someone tells you directly that you can’t do something to set out and prove them wrong. Photovoltaics International, its sister title PV-Tech.org and their publisher Solar Media were told in the early phases of planning the inaugural PV CellTech conference, that pulling together a string of CTOs and R&D heads from the some of the biggest firms in the cell processing supply chain would not be possible. Following the event’s second outing in March 2017, we have now done it twice.

Solar cell demand for bifacial and singulated-cell module architectures

By Nico Wöhrle; Elmar Lohmüller; Max Mittag; Anamaria Moldovan; Puzant Baliozian; Tobias Fellmeth; Karin Krauss; Achim Kraft; Ralf Preu

The first appearance of a shingled solar cell interconnection pattern (see Fig. 1) dates back to 1956 with a US patent filed by Dickson [1] for Hoffman Electronics Corporation, which is just two years after the first publication of a silicon solar cell by Chapin et al. [2]. In the years that followed, further patents were filed containing concepts of shingling solar cells serving various module designs and applications – for example, Nielsen [3] for Nokia Bell Labs, Myer [4] for Hughes Aircraft Company, Baron [5] for Trw Inc, Gochermann and Soll [6] for Daimler-Benz Aerospace AG, Yang et al.

Systematic PV module optimization with the cell-to-module (CTM) analysis software

By Max Mittag, Max Mittag studied industrial engineering and management at the Freiberg University of Mining and Technology. In 2010 he completed his diploma thesis at Fraunhofer ISE and joined the department for photovoltaic modules. His current work includes the cell-to-module efficiency analysis and the development new photovoltaic module concepts.; Matthieu Ebert, Matthieu Ebert holds a ma s t er de g r e e i n r e n ewa b l e en e r g y s y s t ems f rom t h e University of Applied Science, Berlin. Before joining Fraunhofer ISE in 2011 he completed research stays at the Fraunhofer CSE in Boston and at the Australian National University in Canberra. Since 2011 he has been undertaking research on PV module technology. Since 2015 he has led the module efficiency and new concepts team. His main areas of research are module efficiency and CTM analysis, building-integrated PV and PV for automotive applications.

Understanding power losses in technical systems is vital to improve products in every industry and photovoltaic modules present no exception. Losses in solar modules are caused by optical and electrical effects or are determined by simple module geometry through inactive areas.

Supply of low-cost and high-efficiency multi-GW mono wafers

By Yichun Wang, Yichun Wang received a B . S . i n e l e c t r i c a l engineering in 2007 from Northwestern University, China, and an M.S. in electrical engineering in 2010 from the University of Kentucky, USA. She joined LONGi Green Energy Technology Co., Ltd. in 2014, and is currently the application engineering and customer service manager in the silicon wafer business group, where her responsibilities include technical/ product quality support and supervising technical collaboration projects with global institutes and corporations.; Tian Xie, Tian Xie received his Ph.D. in physics in 2004 f r o m H i r o s h i m a University, Japan. He is the director of the quality management department at LONGi Green Energy Technology Co., Ltd., where his primary responsibility is overseeing the quality management, customer service, product design and sales groups at the company

In the Chinese PV market, multi crystalline silicon firmly holds a large market share compared with monocrystalline silicon, entirely as a result of the development of the Chinese PV industry.

Cell modifications for preventing potential-induced degradation in c-Si PV systems

By Gaby Janssen, Gaby Janssen obtained her Ph.D. in quantum chemi s t r y f rom the University of Groningen in the Netherlands. At ECN she has been working as a research scientist on the simulation, characterization and optimization of materials for energy conversion technologies. Since 2011 she has been focusing on simulation and modelling of PV cells and modules; Maciej Stodolny, Maciej Stodolny received his M.Sc. in applied physics from Gdansk University of Technology in Poland. His Ph.D. research at ECN and the University of Twente dealt with Cr tolerance of solid oxide fuel cells. He now works as a solid state physicist and materials scientist at ECN Solar Energy.; Bas Van Aken, Bas Van Aken received his Ph.D. in solid state chemistry from the University of Groningen, after which he worked as a postdoc at Cambridge University and at the Max Born Institute for Nonlinear and Ultrafast Optics in Berlin. He is currently a researcher in the PV module technology group at ECN, where he focuses on fabrication, reliability and (outdoor) performance of bifacial and back-contact modules.; Jochen Löffler, Jochen Löffler holds a Ph.D. in physics from Utrecht University in the Netherlands, and has been working on PV and related topics since 1998. He joined ECN in 2005 and is currently a senior scientist and project leader in the field of crystalline silicon solar cells, with a focus on industrial high-efficiency cells and modules.; Hongna Ma, Hongna Ma holds an M.Sc. and has many years’ experience in silicon solar cell research. She joined Yingli in 2008 and is currently the leader of the group working on n-type Si solar cells. Her focus is on R&D of solar cells with ion implantation technology.; Dongsheng Zhang, Dongsheng Zhang has an M.Sc. and joined Yingli in 2004, where he currently leads the battery technology department. His work experience in silicon solar cell research spans many years, and he has acquired an in-depth understanding of all aspects of the crystalline silicon solar cell process; Jinchao Shi, Jinchao Shi holds an M.Sc. and has worked in silicon solar cell and module research for many years. He joined Yingli in 2006, where he is currently the general manager of the Technology Center. He has extensive experience in lab to fab transference, as well as in cell and module mass production.

In recent years, potential-induced degradation (PID) has been recognized as a serious reliability issue for large PV systems, potentially causing efficiency losses of more than 90%, and even failures [1–4]. Such large decreases in efficiency may require the modules in the system to be replaced after just a few years’ operation. This has motivated a substantial research effort in the PV community, leading to a better understanding of the phenomenon, as well as to a range of mitigation strategies. A recent publication by Luo et al. gives a comprehensive overview of this research [5].

PV manufacturing capacity expansion announcement plans and analysis for Q1 2017

By Mark Osborne, Senior News Editor, Photovoltaics International

Although capacity expansion announcements in January remained subdued and followed the low level of activity seen in the second half of 2016, February proved to be the third busiest month since 2014 and the strongest February in more than three years. March did not maintain that momentum but still posted strong figures, the second highest March figures in more than three years.

Advanced cell and module design for solar LCOE optimization: Is white glass–glass module the future

By Dr. Qiang Huang, Dr. Qiang Huang is vice president of solar BU for GCL System Integration. Prior to joining GCL, he was vice president at Trina Solar for seven years, and a founding director of State Key Laboratories. He also spent seven years working in semiconductors, mainly at TSMC, and holds a Ph.D. from the National Universit y of Singapore.; Li Xinchang, Li Xinchang received h i s b a c he l o r ’s i n a u t o m a t i o n instrumentation from t he Un i v e r s i t y of Shanghai for Science and Technology, and his MBA from Southeast University, China. He is currently a senior module product manager at GCL.

The estimated PV system installation capacity in 2016 was ~70GW worldwide [1], as shown in Fig. 1. In fact, the production volume in 2015 was around 200 times that in 2000, with a compound annual growth rate (CAGR) of over 40%. It has recently been noted that as the PV industry matures, the mindset is changing from $/W to $/kWh. While $/W is still a major driving force, the significance of other factors that influence the cost of energy must also be considered. In this regard, PV development is entering theera of $/kWh-oriented optimization.

Module technology under the microscope

By Finlay Colville

Modules | PV module technology is more advanced and more varied than at any other time. Having pulled together a throng of senior PV technology experts for our PV CellTech conference, PV Tech’s head of market research, Finlay Colville, discusses with John Parnell the need to match these advances with a dedicated event this November.

Digitalisation, drones and data – Intersolar 2017 rolls into town

By Ben Willis

Intersolar preview | The need for ongoing innovation is one of the few givens in the unpredictable solar business. Ben Willis speaks to two of the lead organisers of Intersolar Europe about the likely big topics on the show floor this year and what those tell us about industry’s continuing evolution.

Germany showing the way for storage

By Andy Colthorpe

As with solar, Germany has been one of the leading early adopters of storage. Andy Colthorpe speaks to analyst Valts Grintals about the key drivers emerging for storage in this pioneer country.

O&M in storage: optimisation and maintenance

Battery storage | Operations and maintenance is becoming an important subset of the fast-maturing solar industry but is not yet as clearly defined in the less developed storage business. Andy Colthorpe reports on how efforts to get the most out of battery systems are focused on optimising assets to provide maximum value across a range of markets.

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.

Solar reporting – where does the data come from and who needs it?

By Edmée Kelsey, Edmée Kelsey is founder and CEO of 3megawatt, a software solution provider for the renewable energy industry. 3megawatt has developed BluePoint, the largest and fastest growing enterprise-class asset management platform in the industry. BluePoint is designed to automate and control the entire renewable asset management lifecycle. Kelsey was the former CFO of Main Street Power, where she closed project financing for over 100 distributed solar PV projects and was responsible for the asset management of those solar assets. She was also formerly a VP at the investment bank JP Morgan and managing director of a clean energy corporate finance advisory firm.

Reporting | The growing range of stakeholders in the solar business, from the owners of small rooftop systems to pension funds, require timely and adequate information on asset performance, but to varying levels of detail. Edmée Kelsey looks at how the industry is rising to the increasingly onerous reporting challenge