PV Modules

Solar enterprises will each be faced with the occasional surplus or lack of solar modules in their lifetimes. In these instances, it is useful to adjust stock levels for modules at short notice, thus creating a spot market. Spot markets serve the short-term trade in different products, by enabling the seller to permanently or temporarily offload surplus, while buyers are able to access attractive offers on surplus stocks and supplement existing supply arrangements as a last resort.

With new industrial challenges faced by the PV industry – such as the striking development of Chinese manufacturers, and ever more demanding investors and financial institutions – the quality of PV modules has never been as important as it is today. Because normative requirements are not matching the buyers’ expectations, the questions of what the real quality of a PV module is and how to assess it still remain. This paper analyzes the current situation in terms of quality and the causes of problems, and proposes some ways of addressing the issues in order for the industry to progress on the long path to excellence.

By definition, PV module certification is simply based on conformance to standards. The IEC norms for PV modules are considered to be adequate quality requirements for guaranteeing initial quality. However, it is commonly understood that two products A and B may meet the standard’s requirements, but overall qualty – considering long-term stability, performance and safety – can still be quite different. PV module testing should therefore be carried out more frequently and beyond IEC requirements. A factory inspection once a year – as suggested by most certification bodies to ensure continuous quality of certified crystalline modules – may not be sufficient. The need for additional control is demonstrated in this paper, with reference to our experience from PV module testing and quality assurance activities for wholesalers and project developers. We present the necessity of additional measurements under standard test conditions (STC) and advanced testing methods, which are becoming essential for reliability.

Solar enterprises will each be faced with the occasional surplus or lack of solar modules in their lifetimes. In these instances, it is useful to adjust stock levels for modules at short notice, thus creating a spot market. Spot markets serve the short-term trade in different products, where the seller is able to permanently or temporarily offset surplus, while buyers are able to access attractive offers on surplus stocks and supplement existing supply arrangements as a last resort.

After the encapsulation step, a c-Si solar module’s output is usually decreased, in comparison to its cells’ power, which is referred to as ‘power loss’. This paper focuses on the various factors that can impact power loss of solar modules, such as solar cell classification, encapsulation material, match of solar cells, the encapsulation process used, and so on. The conclusion indicates that power loss in solar modules can be significantly decreased with a resulting increment of a module’s output by appropriately optimizing those factors.

Solar enterprises will each be faced with the occasional surplus or lack of solar modules in their lifetimes. In these instances, it is useful to adjust these stock levels at short notice, thus creating a spot market. Spot markets serve the short-term trade of different products, where the seller is able to permanently or temporarily offset surplus, while buyers are able to access attractive offers on surplus stocks and supplement existing supplyarrangements as a last resort.

Since the 1980s, ethylene-vinyl acetate (EVA) has been the standard encapsulation material for crystalline photovoltaic modules. From a mechanical point of view, the encapsulant takes the function of a compliant buffer layer surrounding the solar cells. Therefore, understanding its complex mechanical properties is essential for a robust module design that withstands thermal and mechanical loads. In the cured state after lamination, its stiffness features a high sensitivity to temperature especially in the glass transition region around -35°C, and a dependence on time which becomes obvious in relaxation and creep behaviour. This paper outlines the viscoelastic properties of EVA and the corresponding standard experimental methods, as well as the impact on the accuracy of wind and snow load test procedures for PV modules.

Solar enterprises will each be faced with the occasional surplus or lack of solar modules in their lifetimes. In these instances, it is useful to adjust these stock levels at short notice, thus creating a spot market. Spot markets serve the short-term trade of different products, where the seller is able to permanently or temporarily offset surplus, while buyers are able to access attractive offers on surplus stocks and supplement existing supply arrangements as a last resort.

This article highlights an alternative method for increasing short-wavelength external quantum efficiency (EQE) and hence overall conversion efficiency of mc-Si PV modules via luminescent down-shifting (LDS), a technique originally proposed by Hovel et al. [1] in 1979. The potential for efficiency enhancement via LDS has been either predicted or measured for a wide range of PV technologies (see [2] for a review). However, in this article, we will highlight how LDS can be incorporated into the existing encapsulation layer, avoiding any modification to well-established solar cell manufacturing processes and thus offering the potential of a production-ready technology.

The majority of solar module manufacturers use ethylene-vinyl acetate (EVA) copolymer foils as the encapsulant material for solar cells and thin-film modules. Because EVA needs long processing times for curing, thermoplastic process materials that do not employ chemical cross-linking have been coming more and more into focus in the encapsulation sector. This paper takes a look at the mechanical temperature-dependent properties of a variety of such materials.