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CHAPTER 1.INTRODUCTION 

TABLE OF CONTENTS 

1.1 LEGAL AUTHORITY ....................................................................................................... 1-1

1.2 HIGH-INTENSITY DISCHARGE LAMP DEFINITION ................................................. 1-2
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CHAPTER 1. INTRODUCTION 

The U.S. Department of Energy (DOE) conducted an analysis to determine the potential 

energy savings for high-intensity discharge (HID) lamps. This analysis will provide a basis for 

the Secretary of Energy to make a determination if mandatory energy conservation standards are 

technologically feasible and economically justified, and would result in significant energy 

savings. 

This technical support document contains the market assessment; technology assessment; 

engineering analysis; life-cycle cost (LCC) and payback period (PBP) analysis; and national 

energy savings (NES) and net present value (NPV) analyses. Each of these sections addresses 

questions such as: 

Market assessment – How large is the HID lighting market? How are HID lamps 

specified (i.e., which products will service a particular application)? What are the 

distribution channels for HID lamps? What product applications will DOE consider in 

this analysis? 

Technology assessment – What are the HID lamp technologies and their performance 

characteristics? What are the ballasts that operate them? 

Engineering analysis – If energy conservation standards remove certain HID lamps from 

the market, which technologies might consumers choose instead? Which high-volume 

HID markets should DOE consider in its LCC analysis? 

LCC and PBP analysis – What LCC and PBP calculation methods does DOE’s LCC 

model for HID lamps use? What are the inputs to the model? How did DOE gather 

pricing and other input data for the model? What are the LCC and PBP results? 

NES and NPV analyses – What NES and NPV calculation methods does DOE use for 

HID lamps? What are the inputs to the NES and NPV model? How did DOE gather input 

data for this model? What are the NES and NPV results? 

1.1 LEGAL AUTHORITY 

DOE conducted this analysis of potential energy savings under the authority of Section 

346 of the Energy Policy and Conservation Act (EPCA) (42 U.S.C. 6317), which states: 

Sec. 346. Energy conservation standards for high-intensity discharge lamps, 

distribution transformers, and small electric motors 

a. High-intensity discharge lamps (and distribution transformers) 

1. The Secretary shall, within 30 months after October 24, 1992, 

prescribe testing requirements for those high-intensity discharge 

lamps (and distribution transformers) for which the Secretary 

makes a determination that energy conservation standards would 

be technologically feasible and economically justified, and 

would result in significant energy savings. 
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2. The Secretary shall, within 18 months after the date on which 

testing requirements are prescribed by the Secretary pursuant to 

paragraph (1), prescribe, by rule, energy conservation standards 

for those high-intensity discharge lamps (and distribution 

transformers) for which the Secretary prescribed testing 

requirements under paragraph (1). 

3. Any standard prescribed under paragraph (2) with respect to 

high-intensity discharge lamps shall apply to such lamps 

manufactured 36 months after the date such rule is published. 

Thus, the Secretary of Energy will make a determination whether energy conservation 

standards for HID lamps are technologically feasible and economically justified, and would 

result in significant energy savings. If the Secretary finds that energy conservation standards are 

warranted, DOE will begin work on a test procedure. After the test procedure is issued, DOE will 

conduct a standards rulemaking process to establish energy conservation standards for HID 

lamps, based on DOE’s annual priority setting process. 

1.2 HIGH-INTENSITY DISCHARGE LAMP DEFINITION 

The Code of Federal Regulations (CFR) currently defines HID (10 CFR 431.282), 

mercury vapor (10 CFR 431.282), and metal halide (10 CFR 431.322) lamps as follows: 

High intensity discharge lamp means an electric-discharge lamp in 

which--

The light-producing arc is stabilized by the arc tube wall temperature; and 

The arc tube wall loading is in excess of 3 Watts/cm2, including such 

lamps that are mercury vapor, metal halide, and high-pressure sodium lamps. 

Mercury vapor lamp means a high intensity discharge lamp, including 

clear, phosphor-coated, and self-ballasted screw base lamps, in which the major 

portion of the light is produced by radiation from mercury typically operating at a 

partial vapor pressure in excess of 100,000 Pa (approximately 1 atm). 

Metal halide lamp means a high intensity discharge lamp in which the 

major portion of the light is produced by radiation of metal halides and their 

products of dissociation, possibly in combination with metallic vapors. 

The CFR does not define high-pressure sodium (HPS) lamps. Therefore, DOE reviewed 

the American National Standards Institute (ANSI) and the Illuminating Engineering Society of 

North America (IESNA) definitions for HPS lamps. 

ANSI C82.9-1996 defines HPS lamp as “a high-intensity-discharge lamp in which the 

major portion of the light is produced by radiation from sodium vapor operating at a partial 

pressure of about 6.67 x 103pascals (50 torr) or greater.” 
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The IESNA LIGHTING HANDBOOK: Reference and Application, 9th Edition, defines 

HPS lamp as “a high-intensity discharge (HID) lamp in which light is produced by radiation 

from sodium vapor operating at a partial pressure of about 1.33 x 104 Pa (100 Torr). Includes 

clear and diffuse-coated lamps.” 

Low-pressure sodium (LPS) lamps are often considered HID lamps, but this distinction is 

incorrect. 

ANSI defines LPS lamps as “a discharge lamp in which light is produced by radiation 

from sodium vapor operating at a partial pressure of 0.13 to 1.3 pascals (10-3 to 10-2 torr).” 

IESNA defines LPS lamps as “a discharge lamp in which light is produced by radiation 

from sodium vapor operating at a partial pressure of 0.1 to 1.5 Pa (approximately 10-3 to 10-2

Torr).” 

Due to the lower pressure, the arc tube wall loading for LPS lamps is lower than the three 

watts per square centimeter defined in the CFR for HID lamps. The full title of ANSI C82.9-

1996, American National Standard for High-Intensity Discharge and Low-Pressure Sodium 

Lamps, Ballasts and Transformers –Definitions, highlights that LPS lamps are not HID lamps. 

Therefore, this analysis does not incorporate LPS lamps. However, it is still important to note 

that many within the lighting industry generally treat LPS lamps as HID lamps.