As a relative newcomer to the industrial world compared to more mature manufacturing sectors, the PV industry has not yet been subject to consistent environmental regulatory standards internationally. Like all industries that have preceded it, PV manufacturing is seeing its regulatory future evolve as PV producers migrate to different regions of the world. With this global expansion come significantly different levels of regulatory stringency, reflective of local conditions and cultures.
Several PV module producers have performed a carbon footprint analysis and published a sustainability report as part of their corporate social responsibility policy. Comparison of carbon footprint results is difficult because several international standards and life cycle assessment (LCA) databases are used. No product footprint category rules (PFCR) or product category rules (PCRs) for photovoltaics exist, so LCAs are performed with varying underlying assumptions. Furthermore, a fair comparison can only be made when all environmental footprints of a product are taken into account.
For a vertically integrated solar cell production starting with purification of silicon feedstock and ending with the production of solar cells, it is necessary to have control over all possible parameters that may affect yield, efficiency and product quality. This paper presents an approach for tracking products with minimal effort using a contactless technique. The method allows wafers to be virtually reconstructed into bricks and ingots, as well as recognizing the precursor wafer for each solar cell.
How much carbon is emitted in producing a solar PV module and launching it on the market? This could be an important question which project developers, installers, investors, government agencies and end customers might ask solar PV manufacturers in the future. To answer it, producers need to know the direct emissions from the manufacturing process, as well as those generated from the activities of manufacturers in the upstream supply chain (including raw material acquisition, upstream energy use, packaging, transportation and procurement), and also those arising from module usage and eventual recycling. This paper, written in a cooperation between EuPD Research and Deutsches CleanTech Institut (DCTI), presents an overview of PV’s carbon footprint.
Various economic and political influences continue to push high-volume manufacturing of semiconductor and PV devices into relatively arid and water-constrained geographies. As the social, economic and political focus on water resources and sustainability increases daily, the need to address the supply, use and disposal of water at manufacturing facilities is growing increasingly more complex. Historically, PV manufacturing has not been considered a major water consumer so there has been little scrutiny of water management. As the costs of water and wastewater disposal spiral upwards, water resource management becomes a significantly more important factor in the capital and operating costs of PV manufacturing. This paper outlines the preparation of a water management diagram (WMD) with reference to the development of water systems for new PV manufacturing plants, and discusses some cautionary design considerations.
As the solar photovoltaic industry has matured from MW-scale pilot plants to large-scale mass manufacturing, costs of solar cells have steadily fallen. To further drive down costs of solar electricity beyond grid parity, a new approach that is being used is to investigate how photovoltaic manufacturing fits into the industrial ecology of a region. Optimizing the utilization of the waste associated with photovoltaic manufacturing itself and its components, while carefully considering geographic proximity, allows for industrial symbiosis. Industrial symbiosis engages traditionally separate industries in a collective approach to competitive advantage, involving physical exchange of materials, energy, water and/or by-products. Preliminary studies and industrial experimentation with co-production/co-location indicate that industrial symbiosis in photovoltaic manufacturing not only improves photovoltaic technology’s already stellar life-cycle environmental performance, but also provides for additional revenue streams that can be used to further reduce photovoltaic device costs. For example, simply coupling a glass manufacturing plant making substrates to a GW-scale amorphous silicon thin-film photovoltaic manufacturing plant, and using recycled glass where technically viable, can lead to a reduction of 30,000 tons/year in raw materials and a 12% reduction in embodied energy. Coupling the glass plant to a greenhouse to make use of waste heat means that more than 700 tons of tomatoes can be grown each year. Both these material and energy savings and additional revenue streams contribute to lowering photovoltaic manufacturing costs, which will play a progressively more important role in photovoltaic manufacturing at the large (>GW) scale.
This paper presents the Q-Cells research line (RL) as a core of the Reiner Lemoine Research Centre, including the technical set-up, the organization of the operation and current results of cell concepts processed in the RL on a regular basis. Trends of cell parameters for those processes are shown, and a focus is presented regarding the results of our high-efficiency cell concepts for multi- and monocyrstalline material processed in the RL with stabilized record efficiencies of 18.4% and 19.2%, respectively. In addition, we discuss the process flow and the results of a monitoring procedure that is used to check the rear-side passivation quality of the company’s equipment. Results of our current passivation stack show a surface recombination velocity of below Srear < 10cm/s, well suited to fabricating p-type Si solar cells with efficiencies above 20%.
Supporting a smooth application of new wafer materials and handling equipment into photovoltaic mass production requires extensive testing of new wafers and equipments under a range of potential operating conditions. The management of such experiments, both in laboratory and production environments, demands the integration and management of a multitude of differing information. This includes static data-like equipment, specifications and experiment settings, online machine data regarding process signal and events – but also unstructured human knowledge, which is available in manual and test reports. To efficiently deal with these kind of complex environments, knowledge management techniques have proven to be a promising approach in various industrial applications. This paper depicts, by means of a photovoltaic wafer-testing platform at Fraunhofer IPA, how the application of automation systems and knowledge management techniques leads to more effective experiment management. More precisely, the gathered knowledge from the wider range of information included in the analysis of experiments can be re-used during future experiments and the manual effort is significantly reduced.
In 2006, Conergy AG started construction on one of the most advanced solar factories in the world in Frankfurt (Oder). On 35,000 square metres, a fully integrated and fully-automated wafer, cell and module production facility was created – all under one roof. Since 2008, production has been running at full speed and every day more than 3,000 premium modules roll out of the factory. This paper outlines the Manufacturing Execution System (MES) process put in place by Conergy during the planning phase of the factory, to monitor and control the complex and merging production processes.
This article provides an overview of the typical waste water treatment methods for crystalline silicon solar cell production. Firstly, a short description is provided of the main process steps of photovoltaic production and the types of waste water generated during these steps. Secondly, the typical waste water treatment methods of hydrogen fluoride (HF) precipitation and neutralization are presented. Furthermore, some options for the reuse of rinse water are discussed and several guidelines for the design of waste water treatment systems are given. Finally, the relative environmental impact of the waste water treatment compared to the emissions of the whole fab is presented using the life-cycle assessment (LCA) methodology.