Abstract

Efficient illumination of classrooms is one of many technologies that can help in constructing a cleaner future and have a positive environmental impact. However, the long-term economic plan of their implementation must still be created and validated. One promising technology is light-emitting diodes (LEDs) that have a low carbon footprint compared to conventional lighting sources. However, different studies barely mention lumen degradation, which is reduction in the illumination capacity throughout LEDs’ lifetime. This paper investigates whether it is economically viable to switch fluorescent lamps to LED lamps while considering lumen degradation of both technologies, by considering the study case to be a classroom of a Kazakhstani university. The performance assessment was based on life-cycle cost analysis (LCCA). The required luminosity level, model lifetime (13 years) and classroom layout were the same for both technologies. The software RETScreen was used to develop the energy model and LCCA and the risk assessment of financial parameters. Simple and equity payback periods were found to be less than half of model lifetime with the internal rate of return reaching 20% and the electrical energy expenses decreasing by 10.95 kWh per year per m² of the classroom, i.e., over 35%. The greenhouse gases (GHG) emissions dropped by 4.38 kgCO₂ eq. per year per m² of the classroom, which is over 30%. This analysis supports the advantages of using LEDs instead of fluorescent lamps, as a financially favorable decision that also reduces GHG emissions despite the high lumen deterioration of LEDs.

Graphic abstract

中文翻译：

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流明退化对荧光灯到LED开关的影响：演讲室的技术经济可行性

摘要

高效的教室照明是许多技术中的一种，可以帮助构建更清洁的未来并产生积极的环境影响。但是，仍必须制定和验证其实施的长期经济计划。一种有前途的技术是与传统光源相比具有低碳足迹的发光二极管（LED）。但是，不同的研究几乎没有提到流明退化，这是整个LED寿命中照明能力的下降。本文通过将研究案例视为哈萨克斯坦大学的教室，研究了在考虑两种技术的流明衰减的同时将荧光灯切换为LED灯是否在经济上可行。绩效评估基于生命周期成本分析（LCCA）。所需的发光度等级，两种技术的模型寿命（13年）和教室布局都是相同的。RETScreen软件用于开发能源模型和LCCA以及财务参数的风险评估。发现简单和公平的投资回收期不到模型寿命的一半，内部收益率达到20％，每年每m的电能支出减少10.95 kWh²个教室，即超过35％。温室气体（GHG）排放量减少了4.38 kgCO ₂ eq。每年每m ²教室的数量，超过30％。该分析支持使用LED代替荧光灯的优势，这是一项财务上有利的决定，尽管LED的光通量大大降低，但该决定还减少了温室气体的排放。

图形摘要