Photovoltaics International Volume 33

‘Silicon Module Super League’ (SMSL) member Jinko Solar has reported the second consecutive quarter of solar module shipments that were higher than leading SMSL rival, Trina Solar.

Passivated emitter rear contact (PERC) production is forecast to exceed 15GW in 2017, accounting for more than 20% of all p-type solar cells produced in the year. PERC has become the first major application for lasers in the mainstream c-Si cell sector in the solar industry, with all other applications either legacy/dormant or as part of process flows that may reside permanently in the research lab or at best make it into production, several years from now.

GCL-Poly Energy Holding has placed a bid of US$150 million for the polysilicon assets of bankrupt renewable energy firm SunEdison via the US bankruptcy court dealing with the Chapter 11 proceedings.

The solar yieldco business model was “flawed from the beginning” according to Santosh Raikar, managing director of renewable energy investments at State Street Bank.

Canadian Solar has made a third major revision to its planned manufacturing capacity expansion plans for 2016, while reiterating previously guided PV module shipments and revenue for the year.

CIS thin-film module manufacturer Solar Frontier has signed a memorandum of understanding with Saudi Aramco and the Saudi Arabian National Industrial Cluster Development Program (NICDP) on the feasibility of establishing a thin-film module production plant in Saudi Arabia.

An efficient exchange of knowledge is essential to move the technology forward. In June 2016, the IW-CIGSTech workshop was organized for the seventh consecutive year in a row. This time, the event took place as a parallel event to the EU-PVSEC/Intersolar Europe in Munich. In the workshop, representatives from industry and academia gathered to discuss the latest developments in the fast-developing field of CIGS (Cu(In,Ga)(Se,S)2) based solar cells. As a result of last year’s workshop, a joint, community-wide effort resulted in the broadly acknowledged “White Paper for CIGS thin film solar cell technology”. In this article, we provide a brief impression of the progress and challenges reported in this year’s workshop.

The rebound in solar cell capital expenditures during 2015 and 2016 has resulted in strong capacity additions and upgrade spending that is set to redefine the technology landscape in 2017 and beyond. Within this however is a broad range of drivers, impacting the mix of n-type and p-type cells produced, in addition to the various strategies employed to increase cell efficiencies while reducing overall blended manufacturing costs. Coupled with the various module types being selected within the key global end markets, and the balance between effective capacity and market demand, 2017 is forecast to see a range of approaches adopted by cell producers, with technology differentiation becoming increasingly important across the entire industry.

In this quarterly report of global PV manufacturing capacity expansion announcements in the first half of 2016, key analysis is given on the continued high level of activity through the second quarter of the year. This report also includes a new bottom-up analysis of ‘effective’ capacity expansions since the beginning of 2014 to provide a better and more accurate assessment of the current manufacturing environment.

This paper examines the use of stencil printing instead of screen printing in order to achieve improved fine line print quality for greater efficiency. In addition, a comparison of polymer and metal squeegees on fine line print performance is analyzed, with varying line apertures studied to understand the impact on the efficiency of PERC solar cells.

The continual increase in cell efficiency of passivated emitter and rear cells (PERCs), as well as the optimization of the module processes, has led to significant advances in module power and efficiency. To achieve the highest module power output, one important aspect to consider is the optimization of the solar cell front metallization and the cell interconnection.

Most high-efficiency solar cells are fabricated from monocrystalline Czochralski (Cz) silicon (Si) wafers because of the high quality of the material. Despite the considerable heritage from microelectronics, the Cz-Si substrate quality can still limit cell performance.

Cell-to-module (CtM) loss is the loss in power when a number of cells are interconnected and laminated in the creation of a PV module. These losses can be differentiated into optical losses, leading to a lower photogenerated current, and resistive losses, leading to a decrease in fill factor. However, since the application of anti-reflection (AR) coatings and other optical ‘tricks’ can sometimes increase the Isc of the module with respect to the average cell Isc, the CtM loss in such cases needs to be expressed as a negative value, which gives rise to confusion. It is proposed to use the CtM change, where a negative value corresponds to a loss in current or power, and a positive value to a gain. In this paper, the CtM changes for back-contact modules utilizing a conductive foil are described and compared with other mature module technologies. A detailed analysis of the CtM change for a full-size metal-wrap-through (MWT) module is presented.

Higher power generation yield is the prime objective of any solar power plant developer. The quality and reliability of the modules used are therefore a key aspect, with customers placing stringent criteria on cell and module manufacturers with regard to product quality. Electroluminescence (EL) image monitoring, which gives a clear picture of defect distribution across a module, is an increasingly popular quality criterion.

With the PV industry continually pushing for ever-higher silicon solar cell efficiencies, the requirements on the electronic quality of the bulk material are becoming more stringent. Advanced characterization of silicon ingots after cutting into bricks allows early quality control and immediate feedback in crystal growth, thereby facilitating shorter R&D cycles, higher yield, lower cost and higher product quality in mass manufacturing.

Light-induced degradation (LID) in both Czochralski (Cz) and multicrystalline p-type silicon is one of the biggest challenges currently faced by the PV industry. Over the next few years it will be necessary to develop cost-effective solutions and integrate them into manufacturing lines. This is particularly important for the successful adoption of the passivated emitter rear cell (PERC), since this cell architecture has been shown to be highly susceptible to degradation.

The p-type monofacial passivated emitter and rear cell (PERC) is currently entering into mass production, but the efficiency of this type of cell is affected by light-induced degradation (LID). A novel solar cell design is introduced here – BiCoRE, which is an acronym for ‘bifacial co-diffused rear emitter’.