Your daily dose of photovoltaic technology developments and solar news

The European PV committee of EPIA/SEMI released the new PVECI standard that describes a unified IT interface for PV equipment in March 2009. If used properly, it provides the PV industry with a powerful tool for reduction of IT-related issues – especially between the factory planning and the ramp-up phase – and establishes the basis for deploying advanced factory management and control software systems. The first part of this article describes the standard in detail while the second part focuses on the anticipated benefits regarding IT integration and outlines further possibilities of a pervasive production-IT landscape.

The aim of this paper is to provide an overview of the methods of automation and their application areas. Current technologies and their applications in both crystalline and thin-film technology will be the main focus, with detailing of the value chain, starting from the feedstock to the finished product. For ease of discussion, the focus is on the part of the value chain where discrete manufacturing on the substrates takes place.

Although simple in concept, a photovoltaic solar cell is a difficult feat of technology in execution. The challenge of balancing cell structure design, material optimization and module technology to achieve efficient, low-cost modules that perform in aggressive environments for up to a generation is huge. The modules’ structure has to support and protect a thin, fragile slice of semiconductor, while ensuring a stable environment free from contamination and moisture with little or no change in the incident light on the cell.

Explosive growth in sales of critical subsystems and components for use in photovoltaic manufacturing equipment provided one of the few bright spots in an otherwise depressed market during 2008. The outlook for sales into the PV industry in 2009 is for demand to be relatively flat, but strong underlying demand for PV cells should lead to a recovery in 2010 and a return to double-digit growth rates, as outlined in this paper.

The principal paths to cost reduction for the photovoltaics industry are increasing the efficiency of solar cells and the power density of modules, together with the reduction of the specific consumption of silicon. Following the slowdown in the ever-increasing growth of the PV market earlier this year, and the reduction in the market cost of polysilicon, wafer producers and most cell producers moved back to the 180μm generation substrates.

Amorphous silicon is one of the most effective materials in passivating silicon interfaces. At Fraunhofer ISE, highly passivating amorphous silicon coatings were developed by an industrially applicable Plasma-Enhanced Chemical Vapour Deposition (PECVD) process. Thin-film stacks of amorphous silicon and SiOx display excellent passivation quality, indicated by effective charge carrier lifetimes ranging from 900 to 1600μs and resulting surface recombination velocities between 9 and 3cm/s-1.

At First Solar’s corporate headquarters in Tempe, Arizona, a morale-boosting slogan adorns posters stuck to the outside of cubicle partitions: “MILESTONE MADE! TEN ONE ONE.” That’s “Ten,” for 10 years in business – at least in the company’s First Solar incarnation. The original firm Glasstech Solar, led by visionary Harold McMaster, actually set up shop in 1984, then became Solar Cells, Inc. in 1992, which begat the present entity in 1999. The middle “One” stands for the gigawatt’s worth of panels produced in the solar module factories in Ohio, Germany, and Malaysia – as well as the annual production capacity that will be ramped by the end of 2009. The final “One” stands for perhaps the biggest accomplishment of all – the dollar-per-manufactured-watt standard beaten by two cents by First Solar in the final quarter of 2008, a cost that has since shrunk to 93 cents per watt in the first quarter of 2009. But then, “Ten/One/0.93” doesn’t quite have the same ring.

A variety of thin-film technologies are now entering a volume manufacturing phase. The benchmark has already been set by First Solar, Inc. in its conversion efficiencies, volume ramp and lowest cost-per-watt in the PV industry. Large-area thin-film deposition is a critical process step, dictating cell performance, reliability and manufacturing throughput. However, adoption of thin-film solar cells has been limited in the past by relatively complex and costly manufacturing processes. The advent of rotating cylindrical magnetrons for sputtering is demonstrating the potential to significantly reduce thin-film manufacturing costs. In this paper we discuss the basics of the technology and the developments taking place with some of the leading suppliers of sputtering target technology for the PV industry.

Despite the low-cost, high-efficiency, radical form factor promise of many thin-film photovoltaic technologies, scaling these materials to large-volume production has presented a wide array of challenges. Because of the recent polysilicon shortage, an incredible amount of resources have been focused on this goal and many thin-film alternatives are now available.

Over the past few decades, the PV equipment manufacturing market has seen a significant change in technologies. Cell sizes are being increased, while cell thickness has decreased at an ever-increasing speed of technological innovation, from 4'' 340μm cells in the 1990s to 6''+ 180μm being the current industry standard. Thin-film modules pose completely new challenges to module manufacturing technology with a strong integration of the manufacturing of the active layers into the module production flow. This articles analyses the pros and cons of an increased level of line integration from the viewpoint of an established PV module producer.

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.

The current industry situation of more competitive business approaches, increased PV project sizes and investments but declining profit margins renders an accurate knowledge of PV performance a vital factor in remaining competitive. Comprehension of expected lifetime and energy yield of PV generators is essential. Therefore, accurate characterization of PV modules is quickly becoming a more and more significant issue. This article gives an overview of the characterization topics of PV modules in terms of safety, failure susceptibility, overall reliability, system performance and energy rating.

Solar photovoltaic power plants have emerged in recent years as a viable means of large-scale renewable energy power generation. A critical question facing these PV plants at the utility scale remains the competitiveness of their energy generation cost with that of other sources. The relative cost of electricity from a generating source can be compared through the commonly used levelized cost of electricity (LCOE) calculation. The LCOE equation evaluates the lifecycle energy cost and production of a power plant, allowing alternative technologies – with different scales of operation, investment, or operating time periods – to be compared. This article reviews the LCOE drivers for a PV power plant and the impact of a plant’s capacity factor on the system LCOE...

New interconnections requirements for utility-connected photovoltaic systems are coming into force in several European countries, armed with the task of supporting the grid operation and stability. This approach to better integration of photovoltaic systems into the electric power system enables a larger dissemination of renewable energies. This paper presents the new grid code in Germany as an example for improved integration, complemented by a brief report regarding activities currently being undertaken to ensure European harmonisation of interconnection requirements.

Thin-film or crystalline photovoltaic modules? One of the consequences of the rapid introduction of new photovoltaic technologies is the buzz generated in the industry. Large-scale photovoltaic applications are especially sensitive to any question connected with cost optimization. Therefore, stakeholders involved in photovoltaic project development are questioning whether the time has arrived to shift module technologies to large-scale applications.

Despite over 30 years of unprofitability, being viewed as too expensive and in many cases, unattractive, the PV industry has also enjoyed over 30 years of strong growth. Though granted, in the past, this growth was often from a much smaller base than the gigawatt levels experienced today, it is still an impressive achievement. Table 1 provides a history of PV industry growth from 1978 to the present. The data in Table 1 is based on what was sold into the global market to the first point of sale, eliminating double shipment (sales) of technology.

In 2008, the global PV market reached 5.6GW and the cumulative PV power installed totalled almost 15GW compared to 9GW in 2007. Spain represented almost half of the new installations in 2008 with about 2.5GW, followed by Germany with 1.5GW additional connected systems. USA confirmed its trend with 342MW newly installed PV systems, followed by South Korea which registered 274MW of PV installations over the year.