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Energy Efficiency – LED Lighting

Lee Layton, P.E.


Course Outline

The course begins with a review of the U.S lighting market in various sectors such as residential, commercial, industrial, and outdoor lighting.  Chapter two covers the fundamentals of lighting including how light is transmitted, reflected, and how color is discerned.  Chapter three discusses how LED’s work and the factors that influence their operation.  Chapter four discusses the various applications of LEDs in the lighting market.

This course includes a multiple-choice quiz at the end, which is designed to enhance the understanding of the course materials.

Learning Objective

After taking this course you should:

Intended Audience

This course is intended for anyone who want to understand how LEDs can be used to lower energy consumption.

Benefit to Attendees

With rising power costs; energy efficiency is becoming increasingly important.  LED lighting is one way to significantly reduce energy consumption and this course will give the attendee a solid understanding of solid state lighting and how these devices can be applied to reduce energy consumption.

Course Introduction

Lighting represents a significant portion of the total electrical energy consumption in the United States and Solid State Lighting (SSL) offers a way to reduce energy consumption.  One form of solid state lights is LED lamps.  An LED lamp is a solid-state lamp that uses light-emitting diodes (LEDs) as the source of light. The LEDs involved may be conventional semiconductor light-emitting diodes; organic LEDs (OLED); or polymer light-emitting diodes (PLED) devices; although PLED technologies are not currently commercially available.

It is estimated that switching to LED lighting over the next two decades could save $120 billion in energy costs; reduce the electricity consumption for lighting by 25%; and avoid 246 million metric tons of carbon emission.

Since the light output of individual light-emitting diodes is small compared to incandescent and compact fluorescent lamps; multiple diodes are often used together. In recent years; as diode technology has improved; high power light-emitting diodes with higher lumen output are making it possible to replace other lamps with LED lamps. One high power LED chip used in some commercial LED lights can emit 7;500 lumens for an electrical power consumption of 100 watts. LED lamps can be made interchangeable with other types of lamps.

Diodes use direct current (DC) electrical power; to use them from standard AC power they require internal or external rectifier circuits. LEDs are damaged by operating at high temperatures; so LED lamps typically include heat management elements such as heat sinks and cooling fins. LED lamps offer long service life and high energy efficiency; but initial costs are higher than those of fluorescent and incandescent lamps.

Course Content

This course content is in the following PDF document:

Energy Efficiency – LED Lighting

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Course Summary

LEDs offer the potential for cutting general lighting energy use by one-quarter; saving energy dollars and carbon emissions in the process. Their unique characteristics—including compact size; long life and ease of maintenance; resistance to breakage and vibration; good performance in cold temperatures; lack of infrared or ultraviolet emissions; and instant-on performance—are beneficial in many lighting applications. The ability to provide dimming and color control is another benefit of LED lights.

One major roadblock for LED’s is cost. Today; the purchase price of LED lighting products is generally higher than that of their conventional counterparts and the energy savings often aren't enough to offset the difference within an attractive payback period.  While LEDs are often not cost effective today; there's a wealth of information showing that they will continue to decline rapidly in price.

With ongoing research and product development; SSL performance has been increasing steadily. Today; many well-designed SSL products can achieve appropriate light distribution in addition to high efficacy and adequate light output. Market segments where LEDs have made the greatest inroads include residential recessed downlights; kitchen under cabinet lighting; portable desk lighting; task lighting; and outdoor area lighting. On top of their superior efficacy; SSL products can be more controllable than traditional lighting technologies and their lifetimes are not impacted by frequent on-and-off cycling. Adjusting actual usage to better reflect the application's needs—for example; with an occupancy sensor—could result in even greater energy savings.

There's little doubt that solid-state lighting ultimately will emerge as the technology of choice for an unparalleled variety of applications.  At the present time LED’s are right for some applications but not for others; so education and due diligence should be key elements in any lighting specification and purchasing process.

Quiz

Once you finish studying the above course content, you need to take a quiz to obtain the PDH credits.

DISCLAIMER: The materials contained in the online course are not intended as a representation or warranty on the part of PDH Center or any other person/organization named herein. The materials are for general information only. They are not a substitute for competent professional advice. Application of this information to a specific project should be reviewed by a registered architect and/or professional engineer/surveyor. Anyone making use of the information set forth herein does so at their own risk and assumes any and all resulting liability arising therefrom.