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’.
This issue of Photovoltaics International focuses on cell technology trends, manufacturing capacity, cell efficiency, mitigating light-induced degredation, new printing techniques, progress in thin-film technology and studies of studies of multicrystalline PV modules. Finlay Colville also provides a full market analysis of cell technology trends impacting module supply in 2017.
Highlights in this issue include an in-depth piece from the US National Renewable Energy Laboratory on how the market is understanding and dealing with the issue of potential-induced degredation modules. We also feature an exclusive paper from the EU-funded Solar Bankability Project on its work to develop a methodology for assessing the economic impact of technical failures in PV power plants.
This issue turns the focus on energy storage with guides on the top 20 technologies, understanding the costs involved and the how Germany is integrating it as part of its energy transition. We also look at the threat of cyber-attacks on solar plants, why there are still reasons to be cheerful about the large-scale European market and how one link of the US supply chain has clubbed together for a greater say in policy-making. Our regular technical papers cover climate stress on module degradation and the quest for accurate irradiance measurements and we get under the skin of West Africa's first utility-scale solar plant.
Our PV Tech Special Report: Scaling up solar in Sub-Saharan Africa, is a comprehensive guide to the off-grid, micro-grid and large-scale sectors and the financial models that can underpin their successful growth. The comprehensive guide is available to download for all our PV Tech members.
This issue of Photovoltaics International focuses on the steady adoption of PERC as the technology of choice for providing a quick boost to cell performances. Our chief analyst, Finlay Colville, reports that PERC is a key driver for internal technology roadmaps of all silicon cell providers and is indirectly influencing the development of other technologies in competing n-type and thin-film segments. However, PERC is not without its drawbacks, and one of these is its increased susceptibility to light-induced degradation. Other highlights include ISC Konstanz on the future of back-contact technology and ECN on the development of a new technique for minimising recombination losses in silicon solar cells.
