scholarly journals Optimization of photoluminescent materials for lighting energy saving in the built environment

2021 ◽  
Vol 2042 (1) ◽  
pp. 012178
Author(s):  
C Chiatti ◽  
C Fabiani ◽  
A L Pisello
Keyword(s):  
Fossil Fuels ◽  
Emission Spectra ◽  
Light Sources ◽  
Improve Energy Efficiency ◽  
Heating And Cooling ◽  
Lighting Energy ◽  
Exciting Source ◽  
Lighting Systems ◽  
End Use ◽  
Photoluminescent Materials

Abstract In the last decades, fossil fuels have become the primary resource for electricity generation, contributing to the aggravation of problems like global warming and ozone depletion. For this reason, innovative solutions are being continuously developed in order to improve energy efficiency in the construction sector. Beyond heating and cooling, urban lighting plays a significant role on the final energy consumption of a city, including both indoors and outdoors. In this work, photoluminescent materials are investigated as possible light sources to be implemented in urban lighting systems, focusing on the free-cost and renewable luminous gain they provide after being exposed to a proper radiation. In particular, commercially available photoluminescent powders are evaluated by means of spectroradiometric techniques and using a specifically designed experimental setup. Measurements are repeated for different intensities and wavebands of irradiation to identify the most promising “pigment-lamp” combination in terms of (i) luminous intensity and (ii) photoluminescence duration. Results show that the shorter the distance between the emission spectra of the exciting source and the photoluminescent powder, the better the performance of the latter. Therefore, the choice of both afterglow and exciting source cannot be independent from the final system’s application and the required end-use lighting level.

scholarly journals The Role of the Internal Heat Gains for Artificial Lighting on the Energy Performance of Buildings

2021 ◽  
Vol 39 (5) ◽  
pp. 1395-1404
Author(s):  
Guglielmina Mutani ◽  
Edoardo De Nicolò ◽  
Laura Blaso ◽  
Simonetta Fumagalli ◽  
Antonella Tundo
Keyword(s):  
Internal Heat ◽  
Energy Performance ◽  
Light Sources ◽  
Retirement Home ◽  
Climate Conditions ◽  
Artificial Lighting ◽  
Performance Indexes ◽  
Lighting Energy ◽  
Lighting Systems ◽  
Shading Devices

This paper aims to propose a procedure for calculating the energy performance indexes of buildings considering the seasonality of internal gains due to artificial lighting with a monthly quasi-steady-state energy balance. The proposed methodology evaluates the heat gains due to the integrated natural-artificial lighting system with the Lighting Energy Numerical Indicator (LENI). For the evaluation of buildings’ global energy performance and for some energy services, this contribution cannot be considered constant annually as depend strongly by climate conditions. The effect of daylighting, type of light sources-luminaires, building orientation and shading devices could influence lighting contribution of the internal heat gains. Then, the proposed methodology evaluates the internal heat gains with monthly energy balances. This methodology was applied to the case study of the "Brancaccio" retirement home in Matera (IT) for which the values of the energy performance indexes were compared with the standard normative approach using constant internal heat gains. The results of this work underline the importance of performing a detailed analysis that considers the availability of natural light in the different months of the year, the efficiency of the different lighting systems and their power installed per unit of area as a function of the lighting comfort requirements in the different types of environments.

On the Estimate of Energy Efficiency and Reliability of Led Lighting

2016 ◽  
Vol 5 (4) ◽  
pp. 12-15
Author(s):  
Байнева ◽  
I. Bayneva
Keyword(s):  
Energy Efficiency ◽  
Light Sources ◽  
Program Model ◽  
Factors Affecting ◽  
Led Lighting ◽  
Improve Energy Efficiency ◽  
Device Reliability ◽  
Challenges And Opportunities ◽  
Lighting Systems ◽  
Efficiency And Reliability

The article investigates the challenges and opportunities to improve energy efficiency through the use of LED lighting systems. The article deals with the possible methods of testing and analysis of the device reliability. The factors affecting on the performance and reliability of LED light sources and devices are analyzed. The program model for the reliability analysis acceleration is proposed and described.

Organic Light Emitting Diodes - Innovative Light Sources

2019 ◽  
pp. 101-107
Author(s):  
Sergei A. Stakharny
Keyword(s):  
Light Source ◽  
Organic Light Emitting Diodes ◽  
Organic Leds ◽  
Light Sources ◽  
High Quality ◽  
Light Emitting ◽  
Organic Light ◽  
Lighting Systems ◽  
Physical Principles ◽  
Prospects Of Application

This article is a review of the new light source – organic LEDs having prospects of application in general and special lighting systems. The article describes physical principles of operation of organic LEDs, their advantages and principal differences from conventional non-organic LEDs and other light sources. Also the article devoted to contemporary achievements and prospects of development of this field in the spheres of both general and museum lighting as well as other spheres where properties of organic LEDs as high-quality light sources may be extremely useful.

Design of Solar-Powered LED Road Lighting System

2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan
Keyword(s):  
High Pressure ◽  
Renewable Energy Sources ◽  
Junction Temperature ◽  
Mercury Vapour ◽  
Light Sources ◽  
Street Lighting ◽  
Led Light ◽  
Road Lighting ◽  
Lighting Systems ◽  
High Pressure Sodium Lamp

Turkey is rich in terms of renewable energy sources and, therefore, is now encouraging the use of sustainable clean lighting systems in road applications. High pressure sodium lamp is the most widely used type in main roads, but other types of lamps such as mercury vapour lamps or metal halide lamps can be utilized for street lighting. Since it enables energy and money saving, LED light technology has replaced high pressure sodium lamps nowadays. Once solar power system (PV) is integrated with LED lamp for street lighting, the amount of saving and local impact might be enriched. LEDs used as light sources in road lighting luminaires with rising lumen values, decreasing junction temperature, higher colour rendering efficiency, longer lifetime have become more efficient than many light sources with the latest developments. Since the structure of the luminaires in which the LED light sources are used differs from that of the conventional light sources, the optical, thermal and electrical design of the LED luminaires must be considered differently. Thus, this study concentrates upon design considerations and the operating principle of solarpowered LED road lighting luminaire in details. Also, a simple solar panel system was designed and the economical values obtained at the end of 20 years were compared when using the ongrid system and the off-grid system.

scholarly journals An Efficient Method for LED Light Sources Characterization

Electronics ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 1089 ◽  
Author(s):  
Sara Raggiunto ◽  
Alberto Belli ◽  
Lorenzo Palma ◽  
Piergiovanni Ceregioli ◽  
Massimo Gattari ◽  
...  
Keyword(s):  
Efficient Method ◽  
Least Squares Method ◽  
Color Temperature ◽  
Experimental Setup ◽  
Light Sources ◽  
Careful Study ◽  
Source Characterization ◽  
Led Light ◽  
Lighting Systems ◽  
Led Drivers

Digital LED drivers capable of blending the spectrum of two LED fixtures with different Correlated Color Temperatures through the LEDs’ power supply control are widespread. However, the digital control of lighting systems is possible only after a careful study of the LED’s response, in terms of illuminance and Correlated Color Temperature. The proposed work takes advantage of the Tunable White technology for the realization of an efficient method for LED light source characterization. In order to evaluate how the light changes as a function of the electric power supplied by the LED drivers, an experimental setup to characterize LED light sources has been designed. Starting from the data acquired from the experimental setup, a model for dimming the LED driver and obtaining the desired values of quality of light has been developed. The proposed model is based on the least squares method and its accuracy is evaluated by comparing the obtained values of illuminance and Correlated Color Temperature with those measured by an illuminance spectrophotometer. Results achieved an error of 0.3% for Correlated Color Temperature and 1.5% for illuminance using the proposed approximation functions.

scholarly journals Towards the Optimum Light Source Spectrum

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andrew Chalmers ◽  
Snjezana Soltic
Keyword(s):  
Light Source ◽  
Large Scale ◽  
Source Spectrum ◽  
Light Sources ◽  
Luminous Efficacy ◽  
Light Emitting ◽  
Spectral Bands ◽  
Good Energy ◽  
Lighting Systems ◽  
Colour Rendering

This paper is concerned with designing light source spectra for optimum luminous efficacy and colour rendering. We demonstrate that it is possible to design light sources that can provide both good colour rendering and high luminous efficacy by combining the outputs of a number of narrowband spectral constituents. Also, the achievable results depend on the numbers and wavelengths of the different spectral bands utilized in the mixture. Practical realization of these concepts has been demonstrated in this pilot study which combines a number of simulations with tests using real LEDs (light emitting diodes). Such sources are capable of providing highly efficient lighting systems with good energy conservation potential. Further research is underway to investigate the practicalities of our proposals in relation to large-scale light source production.

Development of a three-dimensional color rendition space for tunable solid-state light sources

2021 ◽  
Vol 2021 (29) ◽  
pp. 136-140
Author(s):  
Dorukalp Durmus
Keyword(s):  
Solid State ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Color Discrimination ◽  
Continuous Measure ◽  
Light Sources ◽  
Vast Number ◽  
Lighting Systems ◽  
Single Number

The quality of building electric lighting systems can be assessed using color rendition metrics. However, color rendition metrics are limited in quantifying tunable solid-state light sources, since tunable lighting systems can generate a vast number of different white light spectra, providing flexibility in terms of color quality and energy efficiency. Previous research suggests that color rendition is multi-dimensional in nature, and it cannot be simplified to a single number. Color shifts under a test light source in comparison to a reference illuminant, changes in color gamut, and color discrimination are important dimensions of the quality of electric light sources, which are not captured by a single-numbered metric. To address the challenges in color rendition characterization of modern solid-state light sources, the development of a multi-dimensional color rendition space is proposed. The proposed continuous measure can quantify the change in color rendition ability of tunable solid-state light devices with caveats. Future work, discretization of the continuous color rendition space, will be carried out to address the shortcomings of a continuous three-dimensional space.

A Thermal Model of a Fiber Optic Bundle for a Hybrid Solar Lighting System

2005 ◽  
Author(s):  
Michael J. Cheadle ◽  
Gregory F. Nellis ◽  
Sanford A. Klein ◽  
William A. Beckman
Keyword(s):  
Energy Consumption ◽  
Thermal Model ◽  
Fiber Optic ◽  
Management Strategies ◽  
Design Tool ◽  
Lighting Energy ◽  
Solar Lighting ◽  
Reduce Energy Consumption ◽  
Lighting Systems ◽  
Cooling Loads

Hybrid solar lighting (HSL) systems distribute natural sunlight to luminaires located in office or retail buildings in order to reduce energy consumption associated with conventional lighting systems. HSL systems reduce energy consumption directly by reducing the lighting energy and indirectly by reducing the associated cooling loads. A key component of the HSL system is the fiber optic bundle (FOB) that transmits the light from the collector to the luminaire. The observed thermal failure of the FOB when exposed to concentrated sunlight has motivated the development of a thermal model of this component. This paper describes the development of a predictive thermal model of the heat transfer in an FOB for an HSL system. The model is verified experimentally against temperature measurements obtained in the lab under controlled conditions and provides a powerful design tool that can be used to evaluate alternative thermal management strategies.

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