The workhorse of the photovoltaic industry, crystalline-silicon solar cells, continues to have additional headroom for conversion efficiency improvement as well as decreased production costs. As some companies have already demonstrated, clear pathways exist to bring about the achievement of >20%-efficient monocrystalline cells through the use of existing and novel production techniques. A newcomer to the solar cell and module sector, Suniva, has rapidly become a volume manufacturer using innovations originally developed at the University Center of Excellence in Photovoltaics (UCEP) at the Georgia Institute of Technology. This paper discusses the company’s first- and second-generation production technologies, including the implementation of ion implantation as a high-volume process, as well as details of cell-making approaches in the development stage.
Laser grooved buried contact (LGBC) solar cell technology is proving to be an attractive method of producing solar cells that are designed to operate at one sun and at concentration. Such technology is commercially available at Narec for applications at up to 100 suns. Although LGBC cells can have a higher efficiency at one sun when compared with standard non-selective emitter screen-printed solar cells, a more complex manufacturing process is required for these cells. This paper outlines the approach taken under the FP6 EU funded project “Lab2Line”, in which screen-printing and LGBC solar cell processing techniques are hybridized in order to produce lower cost, high efficiency solar cells.
The recent 30% decline in module market prices is the most telling sign of a need for continuous reductions in PV production costs. With this in mind, the cost efficiency of production processes is, next to stable product quality, a vital objective in the planning of production facilities. In this paper, the lessons learned in the area of cost of ownership (COO) forecasting methodologies will be analyzed and evaluated for their potential application to investment decisions in the PV industry. This paper will analyze the cost structure of the PV industry with the aim of underlining the importance of a systematic cost-of-ownership approach.
A major challenge for the solar industry over the next few years is the reduction of production costs on the road to grid parity. Capacity must be increased in order to leverage scaling effects, production and cell efficiency must also be enhanced, and the industry must focus on intensified process optimization and quality control. Laser marking can make a key contribution to fulfilling these requirements. As hard physical coding, laser marking is applied to the raw wafer at the start of the manufacturing process, making each solar cell traceable along the entire value chain and over its whole lifetime. This paper presents Q-Cells’ laser-supported process for coding each individual solar cell (European patent pending), which will require transition work at the laboratory stage before the company’s innovation is ready for mass production.
The U.S. solar PV market is suffering not from a lack of demand or high prices, but rather from an inconsistent labyrinth of rules and regulations which complicate and prolong uptake. There is significant pent-up demand in the U.S. among developers and especially manufacturers; there is not, however, a commensurate regulatory framework that will enable and encourage this demand to be realized. The U.S. political landscape is deeply divided, and policies that would directly or indirectly effect solar demand are no different from any other in this regard.
The minority carrier lifetime is a key parameter for the performance of solar cells as it characterizes the electrical quality of the semiconductor material. Consequently, accurate and reliable methods to determine the minority carrier lifetime are of enormous interest for both practical process control and the evaluation of the potential and limitations of a specific cell concept. Due to its importance, many different lifetime measurement techniques have been developed and used over the past few decades. This paper aims to present and discuss the most common measurement methods on the one hand, while attempting to shed light on some recent developments on the other. The determination of the minority carrier lifetime of crystalline silicon thin-film (cSiTF) material is illustrated as an example of interest for those who are already familiar with standard lifetime characterization.
The next generation of industrial silicon solar cells aims at efficiencies of 20% and above. To achieve this goal using ever-thinner silicon wafers, a highly effective surface passivation of the cell, front and rear, is required. In the past, finding a suitable dielectric layer providing a high-quality rear passivation has been a major challenge. Aluminium oxide (Al2O3) grown by atomic layer deposition (ALD) has only recently turned out to be a nearly perfect candidate for such a dielectric. However, conventional ALD is limited to deposition rates well below 2nm/min, which is incompatible with industrial solar cell production. This paper assesses the passivation quality provided by three different industrially relevant techniques for the deposition of Al2O3 layers, namely high-rate spatial ALD, plasma-enhanced chemical vapour deposition (PECVD) and reactive sputtering.
Despite the financial crisis and present credit crunch, photovoltaic materials markets experienced only a temporary slide in demand in 2009, with the overall outlook remaining optimistic. This paper presents a strategic analysis review for the materials used in photovoltaic modules, essentially materials for encapsulant, frontsheet, backsheet and anti-reflection coatings. Rising concerns about the need to reduce CO2 emissions and increase the use of renewable energy sources worldwide will stimulate the global photovoltaic market. Feed-in tariffs and politically backed targets boosting renewable energy use will provide further impetus to the photovoltaic market. This, in turn, will have a positive ripple effect on the demand for photovoltaic materials; however, depending on the market share for technology used, i.e. crystalline or thin film for PV energy, the market for materials will be influenced, in addition to advantages and disadvantages of these materials that will influence their market share. With rising awareness about green trends, the future will lie in technologies that offer enhanced energy-efficient solutions at a low cost. Manufacturers who offer products with optimum performance while remaining price-orientated will be poised to gain substantial market share.
PV industry module and component manufacturers have brought down costs significantly over the last four years. This trend is clearly evident as most publicly traded companies continue to grow revenue despite falling module and component prices. However, it is far less clear how downstream system integrators are handling the drop in system prices and contributing to value creation. System prices are generally higher in the U.S. than in Europe despite lower module prices in the U.S. This disparity often raises questions on the part of European PV professionals where these costs come from, and secondly, what have U.S. system integrators done to reduce costs. This article is the second of a two-part series shedding light on how U.S. integrators contribute to a decreasing installed-PV-system cost roadmap by championing value creation in the downstream segment. Focusing on the residential market segment, Part I delved into activity cost savings through innovation in engineering and construction [1]. Part II illustrates how changes in marketing and sales, rebates, interconnection, supply chain management and customer support have evolved considerably over the last several years to result in reduced costs.
The tenth (SNEC Exclusive) edition of Photovoltaics International was published in February 2011 for the SNEC (2011) PV Power Conference. It includes an exclusive simplified Chinese insert. In the journal, Q-Cells SE demonstrates the benefits of laser marking, Fraunhofer IST presents TCO deposition techniques in Thin Films, and we take an in-depth look at the benefits of using selective emitters on an industrial scale with Neo Solar Power.
