Light-Emitting Diodes: Progress in Solid-State Lighting

MRS Bulletin ◽  
2001 ◽  
Vol 26 (10) ◽  
pp. 764-769 ◽  
Author(s):  
Artūras Žukauskas ◽  
Michael S. Shur ◽  
Remis Gaska
Keyword(s):  
Light Emitting ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Lighting Energy ◽  
Carbon Arc ◽  
Negative Environmental Impact ◽  
Gas Flame ◽  
The 19Th Century ◽  
Incandescent Lamps ◽  
Physical Phenomena

Until the beginning of the 19th century, flame produced by combustion was the only source of artificial light. Since then, physical phenomena other than pyroluminescence have been used to produce light. Limelight (incandescence of calcium oxide heated by the flame from an oxyhydrogen blowpipe), gas mantles (candoluminescence of gas-flame-heated rare-earth oxides), and the electrical Jablochkoff candle (an early type of carbon-arc lamp) were among the important milestones that led to modern lighting technology. In the 21st century, most of the residential lighting worldwide is provided by tungsten incandescent lamps. Compact fluorescent lamps are also actively promoted because of their higher performance—a broader spectrum for higher-quality white light and elimination of 100–120-Hz flickering, for example. Most work environments employ fluorescent tubes for general lighting, and street lighting is dominated by sodium lamps. Lighting consumes ∼2000 TWh of energy annually, about 21% of the global consumption of electricity. However, during the past 20 years, none of the conventional lighting technologies has exhibited a significant improvement in efficiency. The drive to save lighting energy and reduce its negative environmental impact (i.e., carbon emissions and the disposal of mercury contained in discharge lamps) stimulates the search for new, efficient sources of light.

scholarly journals Impact of Nonlinear Lighting Loads on the Neutral Conductor Current of Low Voltage Residential Grids

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4851
Author(s):  
Jairo Hernández ◽  
Andrés A. Romero ◽  
Jan Meyer ◽  
Ana María Blanco
Keyword(s):  
Low Voltage ◽  
Light Emitting Diode ◽  
Substantial Impact ◽  
Light Emitting ◽  
Political Incentives ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Lighting Loads ◽  
Incandescent Lamps ◽  
The Impact

In the last decade, mainly due to political incentives towards energy efficiency, the share of lamps with power electronic interfaces, like Compact Fluorescent Lamps (CFL) and Light Emitting Diode (LED) lamps, has significantly increased in the residential sector. Their massive use might have a substantial impact on harmonic currents and, consequently, on the current flowing in the neutral conductor. This paper analyzes the impact of modern energy-efficient lighting technologies on the neutral conductor current by using a synthetic Low Voltage residential grid. Different load scenarios reflecting the transition from incandescent lamps, via CFL, to LED lamps are compared concerning the neutral conductor current at different points in the network. The inherent randomness related to the use of lighting devices by each residential customer is considered employing a Monte Carlo simulation. Obtained results show that the use of CFL has a greater impact on the neutral conductor current of Low Voltage (LV) residential grids and that, with increasing use of LED lamps, a decreasing impact can be expected in the future.

Replacing incandescent lamps with compact fluorescent lamps may delay flowering

2012 ◽  
Vol 143 ◽  
pp. 56-61 ◽  
Author(s):  
Erik S. Runkle ◽  
Sonali R. Padhye ◽  
Wook Oh ◽  
Kristin Getter
Keyword(s):  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Incandescent Lamps

scholarly journals SPACIAL ILLUMINANCES VARIABILITY AND ENERGY CONSUMPTION IN AVIARIES FOR LAYING HENS EQUIPED WITH COMPACT FLUORESCENT LAMPS AND LIGHT EMITTING DIODE

2016 ◽  
Vol 36 (6) ◽  
pp. 962-971 ◽  
Author(s):  
Priscilla A. P. Ribeiro ◽  
Tadayuki Yanagi Junior ◽  
Daniela D. de Oliveira ◽  
Gabriel A. E. S. Ferraz ◽  
Dian Lourençoni
Keyword(s):  
Energy Consumption ◽  
Laying Hens ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps

scholarly journals Reduccion de CO2 por el Uso de Lamparas de Bajo Consumo a Expensas de la Generacion de Residuos Peligrosos Domiciliarios

2018 ◽  
Vol 3 (1) ◽  
pp. 617
Author(s):  
Jorge R. Parente ◽  
Luis N. Leanza
Keyword(s):  
Carbon Dioxide ◽  
High Probability ◽  
Energy Savings ◽  
Environmental Problem ◽  
Mercury Content ◽  
Point Of View ◽  
Environmental Consequences ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Incandescent Lamps

Because the national legislation prohibits the sale of incandescent lamps the argentine citizen can acquire compact fluorescent lamps in their replacement. This situation has led us to develop this work whose main objective is to establish a comparison between these two types of lamps from the energy point of view and its environmental consequences. To this end, we have developed a study based on the last national census in Argentina. While significant energy savings achieved, and as a result lower emissions of carbon dioxide, this leads to an environmental problem due to the mercury content of compact fluorescent lamps. They become in hazardous waste when exhausted their useful lives and are discarded in sites for municipal solid waste. High probability that the lamps are broken and release mercury that can contaminate 19,55 liters of drinking water for kilogram of CO2 saved. We conclude that the regulations required to purchase compact fluorescent lamps instead of traditional incandescent lamps must go accompanied with sustainable alternatives to dispose them appropriately since otherwise we will be replacing an environmental problem with another.

scholarly journals Ultraviolet Radiation Emissions and Illuminance in Different Brands of Compact Fluorescent Lamps

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Shahram Safari ◽  
Sina Eshraghi Dehkordy ◽  
Meghdad Kazemi ◽  
Habibollah Dehghan ◽  
Behzad Mahaki
Keyword(s):  
Energy Efficiency ◽  
Pilot Study ◽  
Occupational Exposure ◽  
Optical Bench ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps ◽  
Uv Irradiance ◽  
Asset Value ◽  
Incandescent Lamps ◽  
One Way Anova

Introduction.Replacing incandescent lamps with compact fluorescent lamps (CFLs), which are three to six times more efficient, is one of the easiest methods to achieve energy efficiency. The present study aimed to evaluate relationships between UV emissions radiated and illuminance CFLs.Material and Methods. This pilot study was conducted on 16 single envelope CFLs. The illuminance and UV irradiance of various types of CFLs are measured on a three-meter long optical bench, using a calibrated lux meter and UV meter, and measurement was done in 10, 25, 50, 100, 150, and 200 cm, in three angles, including 0°, 45°, and 90°, at the ages of 0, 100, and 2000 hours. Result. UVC irradiance was not observed at the distance of 10 cm in all of lamps. The lowest value of UVB irradiance was recorded in Pars Khazar lamp, while the highest value was recorded in Etehad lamps. UVR values measured at different times showed negligible differences; the highest asset value was detected in zero times. One way ANOVA indicated that relationships between UVA irradiance and illuminance were significant (P<0.05).Conclusion. UVB irradiance in most of the lamp in 10 and 25 cm was more than occupational exposure and UVA except for the fact that Pars Khazar 60 watts and Nama Noor 60 watts were less than occupational exposure.

scholarly journals An Introduction to Light-emitting Diodes

HortScience ◽  
2008 ◽  
Vol 43 (7) ◽  
pp. 1944-1946 ◽  
Author(s):  
C. Michael Bourget
Keyword(s):  
Light Emitting Diodes ◽  
Arc Discharge ◽  
Visible Spectrum ◽  
Constant Current ◽  
Light Sources ◽  
Total System ◽  
Light Emitting ◽  
Fluorescent Lamps ◽  
Materials Used ◽  
Incandescent Lamps

Light-emitting diodes (LEDs) are semiconductor devices that produce noncoherent, narrow-spectrum light when forward voltage is applied. LEDs range in wavelength from the UVC band to infrared (IR) and are available in packages ranging from milliwatts to more than 10 W. The first LED was an IR-emitting device and was patented in 1961. In 1962, the first practical visible spectrum LED was developed. The first high-power (1-W) LEDs were developed in the late 1990s. LEDs create light through a semiconductor process rather than with a superheated element, ionized gas, or an arc discharge as in traditional light sources. The wavelength of the light emitted is determined by the materials used to form the semiconductor junction. LEDs produce more light per electrical watt than incandescent lamps with the latest devices rivaling fluorescent tubes in energy efficiency. They are solid-state devices, which are much more robust than any glass-envelope lamp and contain no hazardous materials like fluorescent lamps. LEDs also have a much longer lifetime than incandescent, fluorescent, and high-density discharge lamps (U.S. Dept. of Energy). Although LEDs possess many advantages over traditional light sources, a total system approach must be considered when designing an LED-based lighting system. LEDs do not radiate heat directly, but do produce heat that must be removed to ensure maximum performance and lifetime. LEDs require a constant-current DC power source rather than a standard AC line voltage. Finally, because LEDs are directional light sources, external optics may be necessary to produce the desired light distribution. A properly designed LED light system is capable of providing performance and a lifetime well beyond any traditional lighting source.

Methodology for Measurement of the Blue Light Hazard of Light-Emitting Diodes with Imaging Luminance Meter

2013 ◽  
Vol 455 ◽  
pp. 460-465
Author(s):  
Jie Liu ◽  
Xiao Bo Zhuang ◽  
Hua Yao ◽  
Shan Duan Zhang
Keyword(s):  
Blue Light ◽  
Power Distribution ◽  
Spectral Power ◽  
Color Temperature ◽  
Light Sources ◽  
Weighted Function ◽  
Light Emitting ◽  
Spectral Power Distribution ◽  
Fluorescent Lamps ◽  
Compact Fluorescent Lamps

Most of the measurement methods for blue light hazard (BLH) evaluation are based on radiance, which are too complex and hard to find out the highest radiance. We proposed a methodology for measurement of BLH with imaging luminance meter. We measured the relative spectral power distribution with a spectrometer and the maximum luminance with an imaging luminance meter for LEDs and compact fluorescent lamps, and calculated the BLH weighted radiance. The BLH efficacy and the upper limit of luminance with blue light safe of various light sources were also calculated on the basis of the BLH weighted function. The results show absolute blue light safe can be obtained if the luminance is limited to 100 kcd m2 for color temperature lower than 6500 K. LEDs with high color temperature, especially those without diffused window, have potential risk of BLH. Our method can be used in online measurement of the BLH of LEDs.

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