What does an industry need for sustainable, long-term success? A market, customers and suppliers, and – most certainly – excellent products that can be sold. When looking at various different mature industries there is one thing they all have in common – they have industry-initiated roadmaps! With SEMI’s experience in the semiconductor industry over the last 40 years, the example of the International Technology Roadmap for Semiconductors (ITRS) has proved that pre-competitive industry collaboration among the supply chain and among competitors leads to a reduction in costs, a better time to market and an increased efficiency. Moreover, it helps all players to benefit from jointly solved manufacturing challenges.
Although the different roadmaps for PV vary somewhat from each other, the bottom line always remains the same: exponential growth is predicted over the next 5 –10 years. The latest cell technologies meet the demand for grid parity even in central Europe and PV will therefore continue to be the most popular source of renewable energy. In consequence, the whole PV industry has developed from a niche product towards mass production. Every player along the entire value chain is now faced with the need to stay profitable while meeting the ever-increasing demands of the market. Implementing suitable automation can improve competitiveness and thus pave the way to becoming or remaining successful in this turbulent market.
Recently, PV demand forecasting has seen greater contributions from countries that had previously been lumped together in the rest-of-world (RoW) bucket – a category previously reserved for the collective PV demand from countries or regions outside of major (FiT-stimulated) European PV markets. Research has shown that PV adoption outside Europe will not simply increase overall PV demand levels, but will assist in smoothing out erratic demand cyclicality. At first glance, the increased gigawattage of demand being added from the RoW grouping provides an essential component in driving long-term industry growth scenarios. Non-European PV demand is forecast to increase from approximately 30% to 60% of global PV demand between 2011 and 2016. However, more tangible benefits of having an increased number of countries feeding into the global demand mix extend beyond just the significant ‘growth’ potential this situation offers to the PV supply chain. Of these various benefits, perhaps the one that will provide the greatest level of comfort to the PV supply chain will be a collective ‘smoothing’ effect in quarterly demand swings. This should have a positive effect on factory shipment schedules and hopefully provide an end to some of the boom-and-bust cycles that have negatively impacted the fortunes of the PV supply chain during 2010 and 2011.
Flexible copper-indium-gallium-(di)selenide (CIGS) absorbers offer a wide range of possible applications in rigid as well as flexible and lightweight solar module designs. The main advantage of CIGS in comparison to the well-known flexible module technology based on amorphous silicon is its currently higher efficiency and the promising optimization potential of its efficiency in the future. Because of low cell thicknesses of less than 40µm and the general sensitivity of CIGS to moisture, it is a challenge to develop suitable interconnection and encapsulation technologies that promote long-term reliability of solar modules. Selected aspects of our work in this area will be discussed in this paper.
With current state-of-the-art PV module tests stipulating only a static mechanical load test in accordance with IEC 61215 and IEC 61646 standards, hardly any fatigue stressing is carried out on cells, cell connectors or rigid component parts such as the glass or framing. This paper presents research on dynamic load testing of PV modules and discusses reliability aspects of these essential requirements that must be considered in future standardization work.
Wet chemical process equipment is widely used in industrial solar cell production, and inline etching systems in particular have attracted more and more attention since their introduction 10 years ago. The horizontal wafer transport within these systems has made it possible to think about single-side wafer treatments even for wet chemical process applications. Since its market introduction in 2004, the chemical edge isolation process based on the single-side removal of the parasitic emitter at the rear side of the solar cells has gained an increasing share of the market in comparison to competing technologies that use laser techniques. However, stabilization and control of such a process under mass production conditions remains challenging. The introduction of new high-efficiency cell concepts involving passivated rear sides will increase the importance of single-side wafer treatments, as the final solar cell performance is significantly affected not only by the complete removal of the parasitic emitter but also by an ideally polished surface on the rear side of the wafer.
This paper presents Calyxo’s recent advances in product design that have resulted in independently confirmed peak aperture-area efficiencies of 13.4% for modules and 16.2% for cells. Some insight is given into a suitable product design for achieving the highest reliability possible, even in hot climates such as Australia, with no signs of degradation during the first three years of deployment in the field. These technical advances and the midterm production-cost target of US$0.50/Wp allow a forecast levelized cost of electricity (LCOE) of under US$0.10/KWh, especially in sunny regions of the world.
A typical financial structure for a utility-scale (i.e. larger than a few MW) PV project is the so-called ‘non-recourse project financing’. Experience shows that lenders may occasionally refuse financing because they dislike a technology or even a certain supplier. This past behaviour has created the ‘myth of bankability’ and the perceived necessity of manufacturers to get onto the banks’ ‘bankability lists’. But there is no strictly defined process for doing this, and many of the experienced banks do not even work with such lists for good reason. Moreover, ‘bankability’ is not a feature that a manufacturer or a product can achieve or maintain forever.
Unidirectional solidification of large Si ingots from the melt phase is currently one of the most important technologies for producing mc-Si for PV cells. Si ingot furnaces began from casting equipment, and have been improved by DSS (directional solidification system) or DSS-like methods. To improve PV cell efficiency and reduce costs, intensive development has focused on increasing a single ingot’s volume, reducing impurities and controlling the growth speed and temperature gradient. One of the latest developments of Si ingot furnaces is mono-like crystalline silicon growth using a seed preservation method and more accurate control. The Si ingot furnaces are optimized with precise control of temperature gradients and growth speed for the formation of a large unit of quasi-monocrystalline Si. This optimization can further improve a PV cell’s efficiency by at least 1%. In order to obtain fundamental knowledge about the key process steps that determine the growth and electrical quality of mc-Si via directional solidification in an ingot furnace, a combined modelling-measuring approach is essential. Moreover, a mathematical model of the Si ingot casting process can be used for model-based process control.
Solar photovoltaic (PV) electricity continued its remarkable growth trend in 2011, even in the midst of a financial and economic crisis and despite the PV industry going through a difficult period. Once again PV markets grew faster than anyone had expected, just as they have done for the past decade, especially in Europe but also around the world. While such a rapid growth rate cannot be expected to last forever in Europe, prospects for growth around the world remain high. The results of 2011 – and indeed the outlook for the next several years – show that under the right policy conditions, PV can continue its progress towards competitiveness in key electricity markets and be a mainstream energy source. The major system-price decrease that was experienced in 2011, combined with measures taken in Germany and Italy after the Fukushima nuclear disaster, allowed the market to further develop in 2011, particularly in these two countries. However, the price decrease also helped weaken the policy support in many countries, with policymakers facing growing discontent with regard to the perceived cost of PV and the ailing PV industry in Europe.
