scholarly journals Energy-saving quality road lighting with colloidal quantum dot nanophosphors

Nanophotonics ◽  
2014 ◽  
Vol 3 (6) ◽  
pp. 373-381 ◽  
Author(s):  
Talha Erdem ◽  
Yusuf Kelestemur ◽  
Zeliha Soran-Erdem ◽  
Yun Ji ◽  
Hilmi Volkan Demir

AbstractHere the first photometric study of road-lighting white light-emitting diodes (WLEDs) integrated with semiconductor colloidal quantum dots (QDs) is reported enabling higher luminance than conventional light sources, specifically in mesopic vision regimes essential to street lighting. Investigating over 100 million designs uncovers that quality road-lighting QD-WLEDs, with a color quality scale and color rendering index ≥85, enables 13–35% higher mesopic luminance than the sources commonly used in street lighting. Furthermore, these QD-WLEDs were shown to be electrically more efficient than conventional sources with power conversion efficiencies ≥16–29%. Considering this fact, an experimental proof-of-concept QD-WLED was demonstrated, which is the first account of QD based color conversion custom designed for street lighting applications. The obtained white LED achieved the targeted mesopic luminance levels in accordance with the road lighting standards of the USA and the UK. These results indicate that road-lighting QD-WLEDs are strongly promising for energy-saving quality road lighting.

2021 ◽  
Vol 60 (2) ◽  
pp. 39-46
Author(s):  
Olena Didenko ◽  
Krystyna Suvorova ◽  
Olena Liashenko ◽  
Maria Sukhonos ◽  
Maria Liubchenko

High-quality street lighting improves visual perception of the road and provides for a significant decrease in the number of road accidents. It has been established that the total number of accidents can be reduced by 30% for national roads and by 45% for especially hazard areas (e.g., at intersections). Doubling of the average luminance of the road surface significantly reduces the number of accidents in the dark and twilight. Sufficient street lighting contributes to: reducing electricity consumption; decreasing operating costs; improving the environmental situation; promoting business, tourism and investment activity; decreasing the number of criminal offenses. The analysis of recent research and publications helped choose the best European practices which can be used to improve the outdoor lighting in Ukraine. The street lighting network is continuously growing and being modernized. Different types of light sources are being used in the network to illuminate the city. Today, high-pressure lamps (HPS) are leading. They are increasingly replaced by LED light sources. Not a small share is accounted for by metal-halide lamps. The smallest number of light sources in the street lighting system, high-pressure mercury and compact fluorescent lamps (CFLs). To increase the efficiency of the street lighting system and reduce energy consumption for its operation, measures for its reconstruction and modernization are required. For this purpose, it is necessary to address the following problems: high level of obsolescence and physical wear and tear of system elements; inefficient use and high losses of electricity at the stages of transportation and consumption, due to the use of obsolete and worn-out equipment; suboptimal distribution of the utility capacity, which leads to ineffective use of the existing lighting system; low efficiency of the street lighting control system, due to the lack of electric meters and remote monitoring and control of the street lighting. Introduction of energy-saving types of light sources is one of the ways to modernize the existing street lighting system. It is necessary to replace old lighting fixtures, which have already exhausted their life span, by new energy-saving light sources (replace CFLs by LEDs), use automatic control systems. All this in turn will help reduce energy costs by 60%. To improve energy efficiency of the street lighting system, it is also recommended to carryout the replacement of electromagnetic ballasts by electronic ones. The employment of electronic ballasts, e.g., in case of using HPS 250 lamps, allows to save approximately 255 kWh/year. Considering that the price per kW of electric energy is UAH 2.68, one luminaire helps save the amount of UAH 683.4 per year.


2018 ◽  
pp. 99-109 ◽  
Author(s):  
Sanaz Bozorg Chenani ◽  
Rami-Samuli Rasanen ◽  
Eino Tetri

Road lighting is on the verge of one of the most attentive changes since its first introduction. The synergetic effect of the advancement of road lighting technology and usage pattern is going to change the concept of road lighting. By most estimates, light emitting diodes (LEDs) are the most energy efficient light sources that can be used in road lighting. Today, the energy saving potential when replacing HPS lamps with LED luminaires is one-third with current technology and two-thirds with improved technology in the future. This technological transformation has the potential of energy saving up to 83 % in comparison with HPS lamps. The energy saving is achievable with changing the pattern of use by intelligent road lighting control based on reducing burning hours. Intelligent road lighting can be based on such parameters as traffic density, ambient light, road condition and weather circumstances. It can also be more dynamic and consider the combined effect of road lighting and individual car headlights. The widespread adaptation of these emerging technologies is envisioned to lead towards more sustainable lighting.


2013 ◽  
Vol 291-294 ◽  
pp. 2749-2753 ◽  
Author(s):  
Xin Chen ◽  
Chun Hai Wu ◽  
Xiao Dong Zheng

This paper presents the measurement results of the reduced luminance coefficients of an asphalt pavement sample under three common light sources: high pressure sodium lamp (HPS), metal halide lamp (MH), and light-emitting diode (LED), with a specially designed two-dimensional gonioreflectometer. The relative spectral reflectances are obtained with calculation for three different incident angles which indicate light sources with high output in the long wavelength region may be more effective. The measured average luminance coefficient for HPS and MH are 17% larger than that of LED. It means that LED road lamps need higher illuminance than HPS and MH to realize the same brightness for road lighting.


2019 ◽  
pp. 75-85
Author(s):  
Canan Perdahci ◽  
Hamdi Ozkan

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.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Salah M Alabani

This paper studies the manner of energy consumption in Libyan street lighting systems and general road section. It also suggests proposal system with two cases of operation for an attempt to apply the energy saving program by adopting an optimum method in order to decrease the demand of energy in this section and to reduce the use of uneconomic equipment.The proposal system in this paper introduces the Light Emitting Diode (LED) street lighting technology to be used instead of traditional luminaries High Pressure Sodium (HPS). The proposed system is divided into two cases. The first case discusses the replacement of traditional luminaries (HPS) with energy saving luminaries (LED), while second case explains how integrating control node (dynamic dimmer) into LED in order to dim output lighting in streets will save more energy.This study reaches a result that a significant amount of energy of %47 (about 1092.23 GWh/year) of total energy consumed in street lighting sector could be saved if first case is applied. Moreover, it suggests that more energy of %58 (about 1380.02 GWh/year) of total energy consumed in the same sector cloud be saved if the second case is adopted.


Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 2169 ◽  
Author(s):  
Ana Ogando-Martínez ◽  
Javier López-Gómez ◽  
Lara Febrero-Garrido

This document addresses the development of a novel methodology to identify the actual maintenance factor of the luminaires of an outdoor lighting installation in order to assess their lighting performance. The method is based on the combined use of Radiance, a free and open-source tool, for the modeling and simulation of lighting scenes, and GenOpt, a generic optimization program, for the calibration of the model. The application of this methodology allows the quantification of the deterioration of the road lighting system and the identification of luminaires that show irregularities in their operation. Values lower than 9% for the error confirm that this research can contribute to the management of street lighting by assessing real road conditions.


2019 ◽  
pp. 67-72
Author(s):  
L. Nazarenko ◽  
H. Kononenko ◽  
Т. Mozharovska ◽  
V. Chernets

The article reveals the question of achieving security for people on the streets at night with the help of artificial lighting. The author analyzed the factors affecting traffic safety and the possibility of creating the necessary visual conditions for this by means of street lighting. In addition, the article raised an important question regarding the characteristics of the roadway. It is noted that the modern pavement is not standardized on the lighting characteristics. Knowing the spectral characteristics of the applied light sources, these data could be applied in the development of new types of canvases that would allow achieving a new level of illumination in terms of both improving the quality and its efficiency and economy. Without this, it is impossible to talk about the maximum efficiency of the use of the luminous flux as a whole. For existing lighting systems, the brightness calculation is performed by measuring the illumination and reflectivity of the road surface. The obtained brightness values are entered into the mesopic photometric system in order to determine the parameters of the complete system, which provides equivalent visual perception of the illuminated objects and is intended to replace the existing installation. To determine the required lamp power when replacing existing luminaires, it is recommended to use a mesopic photometric system, which allows you to perform calculations taking into account the S/P ratios. In this regard, it is necessary to thoroughly review the computer programs used in the creation of the lighting project, as well as to ensure active participation in international cooperation in the formation of modern lighting standards.


2021 ◽  
Author(s):  
Margareth Wit

Leadership is learnable. Furthermore, future developments within our organizations will be strongly influenced by our leadership effectiveness. In ten steps Margareth de Wit describes how, as a leader, you can train yourself to achieve desired transitions within your organization. Educated at INSEAD and Wharton, Margareth de Wit has a long and rich experience working at the top of international companies in the USA, India, the UK, and Africa, providing intensive leadership sessions to CEOs, commissioners, managers, and directors. Margareth de Wit has inspired hundreds of professionals within the education sector to see themselves as playing the central role in providing better education through intelligent collaboration in self-managing school teams. Her experiences show that systematic attention to leadership and group dynamics creates organizations that are both successful and future-proof. Providing striking examples from her broad practice and experience, historical comparisons, human interactions, analytical schemes, and evidence-based methods, de Wit paints a picture of the road that leads to effective leadership. While this transition is never finished, it is nevertheless one that always leads to both personal and organizational improvement.


2018 ◽  
Vol 121 ◽  
pp. 105-113
Author(s):  
Piotr Jaskowski ◽  
Piotr Tomczuk

Control of road lighting condition is a key factor in maintaining high standards of lighting and traffic safety for both drivers and pedestrians. Currently, street lighting measurements are taking place mainly at the reception of newly designed installations. It is also necessary to control the lighting status of already operating installations in order to maintain the assumed lighting parameters and carry out their possible maintenance. The article presents the method of measuring luminance using a point and matrix meter in the context of normative requirements.


2019 ◽  
Vol 7 ◽  
pp. 44-51
Author(s):  
Indu Duwal

With the increment in the gap between the demand and supply of energy, various alternatives for decreasing the demand of energy are major concern for the various stakeholders. In order to decrease the energy demand by lighting various energy efficient lights are available in market. However it is difficult to convince the residents to change conventional artificial light sources, since lighting system is an essential part in the building which ensures the comfort, productivity and safety of the occupants in the buildings. Among the various Light Emitting Diode (LED) lights are termed as one of the most efficient energy saving lights which aims to save almost more than 50 % of energy demand than that of CFL lights with same power of illumination. Hence, this study is carried out to calculate energy saving percentage after replacing the conventional lights like florescent, mercury lights and other forms of conventional lights by LED lights. Additionally the study also was focused to evaluate feasibility of the replacement of lights by LED lights in terms of energy saving and return of investment. The research was carried out in building used by Agrotechnology and Food Science (AFSG) science group of Wageningen University in the Netherlands. The results from the study showed that almost 50% of the energy can be saved after replacement by LED lights with around 5 years for return of investment. However, factors like 1) Number of operating hours, 2) Price of lights, 3) Energy cost, 4) Labour cost for replacement and adjustment and 5) Number of replacement and adjustment per hour are the influential features that effects in the performance of various types of lights


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