Photovoltaics International Papers

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.

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.

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].

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.

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 the era of $/kWh-oriented optimization.

Innovation in the field of thin-film cells, in addition to economy of scale and the manufacturing learning curve, is an important element in keeping the price of this technology competitive. Most papers on these cells focus on their technology; however, the economic potential of the technology is also important. Of even greater significance, a realistic estimation of the potential, along with the associated costs, of advanced technology, is part of the equation for profitability. Two examples of technology – metallic grids and texturing – are given in this paper; the designs are discussed, and a brief economic analysis is presented for various scenarios of the technologies. Although the profitability of these technologies can be considerable, it is shown that one should be wary of basing decisions purely on potential and on ideal scenarios, and how the cost of a technology can turn a great prospect into a trade-off.

This paper focuses on the technical progress of high-efficiency crystalline silicon solar cells and modules, specifically with regard to passivated emitter and rear cell (PERC) processes, module description and light induced degradation (LID) data. Through appropriate optimizations of the solar cell and module processes, the cell efficiency achieved in mass production is 21.3%, with module power exceeding 300W. To solve the LID problem, hydrogenation technology developed by UNSW is used, bringing the cell LID rate down to below 1%.

In this quarterly report on global PV manufacturing capacity expansion announcements we will provide a detailed analysis of 2016. Despite a significant slowdown in new announcements in the second half of the year, 2016 surpassed 2015 by around 16% to exceed a total of 55GW of thin-film, dedicated solar cell and module assembly and integrated PV expansion plans.

This paper presents a summary of the status of bifacial PV in respect of the technology in mass production, the installed PV systems, and the costs relating both to module production (cost of ownership – COO) and to electricity (levelized cost of energy – LCOE). Since the first bifacial workshop, organized by ISC Konstanz and the University of Konstanz, in 2012, many things have changed. Bifacial cells and modules have become cost effective, with installed systems now adding up to more than 120MWp and the technology becoming bankable. Large electricity providers have recognized the beauty of bifacial installations, as the lowest costs per kWh are attainable with these systems. The authors are sure that by the end of 2017, bifacial PV systems amounting to around 500MWp will have been installed, and that by 2025 this type of system will become the major technology in large ground-mounted installations.

For many applications, bifacial modules offer a cost-effective way of increasing energy yields, which explains why the interest in bifacial cells in the PV industry is steadily growing and is expected to continue. However, the metallization of bifacial cells creates new challenges, as the same materials and techniques developed for n surfaces are generally not directly, or simultaneously, applicable to p surfaces; this necessitates sequential metallization of each side, resulting in added cost and/or complexity. This paper introduces a simple co-plating approach with the objective of simplifying the metallization of bifacial cells in a cost-effective way, and which is designed for multi-wire module integration. The metallization route is described, and high cell efficiencies of up to 22.4% are demonstrated using this co-plating approach with bifacial nPERT+ cells (where ‘+’ signifies the bifacial nature of these cells). Initial thermal-cycling reliability data of test structures and 1-cell laminates is presented. Finally, cost-of-ownership (COO) estimates are given, which predict the co-plating approach to be ~40% cheaper than bifacial screen-printed metallization. It is shown that the combination of the high efficiency potential of nPERT+ cells and the reduced costs of co-plating has the potential to deliver module-level costs of ~$0.25/Wpe (glass–glass configuration).