LCA Case Study to LED Outdoor Luminaries as a Circular Economy Solution to Local Scale

Life cycle assessment of decommissioned silicon photovoltaic module recycling using different technological configurations in China

The intricate encapsulation structure and material composition of photovoltaic modules necessitate full materials recycling involving multiple stages and different technological configurations, thereby increasing environmental burden of recycling process. Consequently, environmental impact assessments are imperative. However, previous studies primarily focused on a single technology or compared different technologies within a specific recycling stage, overlooking various technological configurations and thus engendering incomprehensive assessment. Hence, we employ a comparative life-cycle assessment to evaluate the environmental performance of six recycling alternatives with different technological configurations for silicon photovoltaic waste in China, which encompasses five recycling stages and glass/silicon remanufacturing processes. Results shows thermal delamination reduces the normalized environmental impact by 8.73% and 4.62% compared with mechanical and chemical delamination, respectively; electrolysis for metals extraction carries 35.72%-36.35% higher environmental benefits than precipitation. Additionally, introducing silicon/glass remanufacturing provides an additional 6.27%-11.55% environmental benefits. Therefore, integrating disassembly, thermal delamination, leaching & etching, electrolysis, and remanufacturing exhibits the best environmental performance, with -4796 kg CO2-eq/tonne carbon emission and -46400 MJ/tonne energy demand. Environmental hotspots analysis identifies key contributors to environmental impact and benefits. Further sensitivity analysis highlights the importance of enhancing silver and copper recovery efficiency. Finally, targeted strategies are proposed for green recycling routes of photovoltaic waste.

Impact of Thermal Dissipation on the Lighting Performance and Useful Life of LED Luminaires Applied to Urban Lighting: A Case Study

Currently, LED technology is an established form of lighting in our cities and homes. Its lighting performance, durability, energy efficiency and light, together with the economic savings that its use implies, are displacing other classic forms of lighting. However, some problems associated with the durability of the equipment related to the problems of thermal dissipation and high temperature have begun to be detected, which end up affecting their luminous intensity and the useful life. There are many studies that show a direct relationship between the low quality of LED lighting and the aging of the equipment or its overheating, observing the depreciation of the intensity of the light and the visual chromaticity performance that can affect the health of users by altering circadian rhythms. On the other hand, the shortened useful life of the luminaires due to thermal stress has a direct impact on the LCA (Life Cycle Analysis) and its environmental impact, which indirectly affects human health. The purpose of this article is to compare the results previously obtained, at different contour temperatures, by theoretical thermal simulation of the 3D model of LED street lighting luminaires through the ANSYS Fluent simulation software. Contrasting these results with the practical results obtained with a thermal imaging camera, the study shows how the phenomenon of thermal dissipation plays a fundamental role in the lighting performance of LED technology. The parameter studied in this work is junction temperature (T_j), and how it can be used to predict the luminous properties in the design phase of luminaires in order to increase their useful life.

The Perspective of Total Lighting as a Key Factor to Increase the Sustainability of Strategic Activities

In the last decades, lighting has evolved from a branch of engineering ensuring safety and performance in indoor and outdoor installations, to a key discipline interacting with a wide spectrum of fields and having a deep impact on our daily lives. Although this evolution also applies to other areas of knowledge, the special features of lighting make its potential and also its limitations different. It is not the typical field where a well-established mathematical framework allows a departure from well-defined input and identifying clear effects and conclusions. The reason is that lighting is a field dealing with the interaction between a physical phenomenon and a physiological and psychological system, the human being. In addition to the complexity of its basis, the relationship between lighting and sustainability has become stronger in recent years. This relationship is bi-directional in some cases: on one hand, advanced societies require more and more complex lighting installations, which means high energy consumption, use of raw materials, financial costs, manufacturing and maintenance processes, waste and emissions to the atmosphere. On the other hand, good lighting has an impact on issues like productivity, well-being, happiness, disease avoidance, safety, and many other qualitative aspects whose direct or indirect impact on sustainability is remarkable. This work will analyze how lighting can give answers to questions related to sustainability, not only from the classic topics of energy consumption and waste management, but from a wider and global perspective. The results of these works are analyzed, and the basis of the new framework of total lighting, discussed.