CHAPTER 4. SCREENING ANALYSIS

TABLE OF CONTENTS

4.1 INTRODUCTION ........................................................................................................... 4­1

4.2 SCREENED­OUT TECHNOLGIES............................................................................... 4­2

4.2.1 General Service Fluorescent Lamp Screened­Out Technologies ........................ 4­2

4.2.1.1 Multi­Photon Phosphors.......................................................................... 4­2

4.2.2 Incandescent Reflector Lamp Screened­Out Technologies................................. 4­2

4.2.2.1 Microcavity Filaments............................................................................. 4­2

4.2.2.2 Novel Filament Materials ........................................................................ 4­3

4.2.2.3 Crystallite Filament Coatings .................................................................. 4­3

4.2.2.4 Luminescent Gas...................................................................................... 4­4

4.2.2.5 Non­Tungsten­Halogen Regenerative Cycles.......................................... 4­4

4.2.2.6 Infrared Phosphor Glass Coating............................................................. 4­4

4.2.2.7 Integrally Ballasted Low Voltage Lamps................................................ 4­5

4.2.2.8 Trihedral Corner Reflectors..................................................................... 4­5

4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED OUT.................................. 4­6

4.4 REMAINING TECHNOLOGIES ................................................................................... 4­6

4.4.1 General Service Fluorescent Lamps Design Options .......................................... 4­6

4.4.2 Incandescent Reflector Lamps Design Options................................................... 4­6

REFERENCES ............................................................................................................................ 4­8

LIST OF TABLES

Table 4.3.1 GSFL Technology Options Screened Out of the Analysis.......................... 4­6

Table 4.3.2 IRL Technology Options Screened Out of the Analysis ............................. 4­6

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CHAPTER 4. SCREENING ANALYSIS

4.1 INTRODUCTION

This chapter discusses the U.S. Department of Energy’s (DOE) screening analysis

of the technology options identified for general service fluorescent lamps (GSFL) and

incandescent reflector lamps (IRL). As discussed in Chapter 3, Market and Technology

Assessment, DOE consults with industry, technical experts, and other interested parties in

developing a list of technology options for consideration. The purpose of the screening

analysis is to evaluate the list of options to determine which to consider further and which

to screen out.

Section 325(o)(2) of EPCA provides that any new or revised standard must be

designed to achieve the maximum improvement in energy efficiency that is determined to

be technologically feasible and economically justified. (42 U.S.C. 6295(o)(2)) In view

of the EPCA requirements for determining whether a standard is technologically feasible

and economically justified, Appendix A to Subpart C of Title 10, Code of Federal

Regulations, Part 430 (10 CFR Part 430), “Procedures, Interpretations, and Policies for

Consideration of New or Revised Energy Conservation Standards for Consumer

Products” (the Process Rule) sets forth procedures to guide DOE in its consideration and

promulgation of new or revised efficiency standards. These procedures elaborate on the

statutory criteria provided in 42 U.S.C. 6295(o) and, in part, eliminate problematic

technologies early in the process of prescribing or amending an energy efficiency

standard. In particular, sections 4(b)(4) and 5(b) of the Process Rule provide guidance to

DOE for determining which design options are unsuitable for further consideration:

1. Technological feasibility. DOE will consider technologies incorporated in

commercial products or in working prototypes to be technologically feasible.

2. Practicability to manufacture, install, and service. If mass production and

reliable installation and servicing of a technology in commercial products could

be achieved on the scale necessary to serve the relevant market at the time the

standard comes into effect, then DOE will consider that technology practicable to

manufacture, install, and service.

3. Adverse impacts on product utility or product availability. If DOE

determines a technology would have significant adverse impact on the utility of

the product to significant subgroups of consumers, or would result in the

unavailability of any covered product type with performance characteristics

(including reliability), features, sizes, capacities, and volumes that are

substantially the same as products generally available in the United States at the

time, it will not consider this technology further.

4. Adverse impacts on health or safety. If DOE determines that a technology will

have significant adverse impacts on health or safety, it will not consider this

technology further.

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Section 4.2 discusses the technology options DOE screened out from further

consideration. Section 4.3 summarizes those options. Section 4.4 lists the remaining

design options DOE considered in its analyses.

4.2 SCREENED-OUT TECHNOLGIES

This section addresses the technologies that DOE screened out, having considered

the following four factors: (1) technological feasibility; (2) practicability to manufacture,

install, and service; (3) adverse impacts on product utility to consumers; and (4) adverse

impacts on health or safety.

4.2.1 General Service Fluorescent Lamp Screened-Out Technologies

DOE has screened out the following technologies in its analyses of GSFL.

Although these technologies were not considered in the subsequent analyses, DOE does

not discourage their use by manufacturers. These technologies may be capable of

reducing energy consumption or providing additional benefits to consumers, even though

they do not currently meet the requirements for DOE’s consideration.

4.2.1.1 Multi-Photon Phosphors

Theoretically, the use of multi­photon phosphors, or quantum­splitting phosphors,

could significantly improve lamp efficacy. By emitting more than one visible photon for

each ultraviolet photon, a lamp would be able to emit more light for the same amount of

power. However, development of this technology remains in the research phase and

DOE is unaware of any prototypes or commercialized products that incorporate multi1 photon phosphors. Thus, DOE screened out this technology option based on the first

criterion, technological feasibility. Additionally, because this technology is still in the

research phase, DOE believes that it would not be practicable, or even possible, to

manufacture, install, and service this technology on the scale necessary to serve the

relevant market at the time of the effective date of an amended standard. It is not

possible to assess whether the technology will have adverse impacts on utility to

consumers, availability, or consumer health or safety. Therefore, DOE will not consider

multi­photon phosphors as a design option for improving the efficacy of GSFL.

4.2.2 Incandescent Reflector Lamp Screened-Out Technologies

DOE screened out the following technologies for IRL. Although DOE did not

consider the following technologies, DOE does not discourage their use since they may

reduce energy consumption or provide other benefits to consumers.

4.2.2.1 Microcavity Filaments

By fabricating microcavities on the incandescent lamp filament, it is theoretically

possible to increase a lamp’s emissivity, and therefore its efficacy. The market and

technology assessment (Chapter 3) notes that Sandia National Laboratories researchers

examined microcavity resonance in a tungsten photonic lattice and found multiple patents

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referencing this technology. Since research prototypes of microcavity filaments do exist,

DOE determined that this technology option is technologically feasible. However,

research indicates that materials patterned at the submicron level may experience

2 problems with stability. Because such instability could negatively affect lamp lifetime,

DOE believes the technology is not yet practical to implement on a wide scale. For this

reason, DOE screened out this technology option based on the third criterion, impacts on

product utility to consumers. DOE is also unaware of any commercialized lamps that

incorporate microcavity filaments, and is concerned that mass­manufacturing techniques

for this technology would be problematic. For this reason, DOE does not believe that this

technology would be practicable to manufacture, install, and service. Therefore, DOE

will not consider filaments with microcavities as a design option for improving the

efficacy of IRL. DOE does not have enough information to assess whether

implementation of this technology will have adverse impacts on consumer health or

safety.

4.2.2.2 Novel Filament Materials

Novel filament materials such as nitrides and carbides have the potential to

improve lamp efficacy by emitting more light in the visible spectrum at a given

temperature than traditional tungsten filaments. Because several patents on such

filaments exist, DOE believes that this technology option is technologically feasible.

However, DOE is unaware of any lamps available today that use such filaments.

Furthermore, DOE understands that technological barriers, such as prohibitive brittleness

of the filament, limit implementation of this technology. Finding a practical way to

incorporate novel filament materials into IRL would require further research, as would

making such lamps practical for general service applications. DOE believes that it would

not be practicable to manufacture this technology on the scale necessary to serve the

relevant market at the time of the effective date of an amended standard. Therefore, DOE

will not consider novel filament materials as a design option for improving the efficacy of

IRL. DOE is unaware of any research on the potential impact of this technology on

consumer health or safety.

4.2.2.3 Crystallite Filament Coatings

DOE screened out crystallite filament coatings, which are oxide­covered micron

or sub­micron crystallites comprised of thorium, tantalum, or niobium. These coatings

can be used to increase the light emissivity of a lamp’s filament. Because several patents

on such filament coatings exist, DOE believes that this technology option is

technologically feasible. However, DOE was unable to locate any data on the

incorporation of crystallite filament coatings into prototype or commercially available

products. Using crystallite filament coatings may require additional manufacturing

techniques, such as chemical vapor deposition. DOE understands that these techniques

are not in use in the mass­production of IRL. DOE believes that it would not be

practicable to manufacture this technology on the scale necessary to serve the relevant

market of IRL at the time of the effective date of an amended standard. DOE screened

out this option based on the second criterion. It is also not possible to assess whether this

technology will have adverse impacts on utility to consumers, availability, or consumer

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health or safety. Therefore, DOE will not consider crystallite filament coatings as a

design option for improving the efficacy of IRL.

4.2.2.4 Luminescent Gas

Luminescent gases encompass gaseous fills for incandescent lamps that react with

certain wavelengths of the filament emission and generate visible light. DOE is unaware

of any existing commercially available products or prototypes of incandescent lamps

incorporating luminescent gases. DOE screened out luminescent gases based on

technological feasibility. To the best of DOE’s knowledge, luminescent gas fills also

have not been incorporated into residential, commercial, or industrial products, so DOE

cannot assess the practicability to manufacture, install, and service this technology on the

scale necessary to serve the relevant market at the time of the effective date of an

amended standard. It is not possible to assess whether this technology will have adverse

impacts on utility to consumers, availability, or consumer health or safety. Therefore,

DOE will not consider luminescent gas fills as a design option for improving the efficacy

of IRL.

4.2.2.5 Non-Tungsten-Halogen Regenerative Cycles

The regenerative cycle of filament evaporation and redeposition can be used to

greatly increase the life of an incandescent lamp and improve lumen maintenance. The

filament can burn at a higher temperature than conventional incandescent lamps while

maintaining a useful service life. The market and technology assessment (Chapter 3)

discusses the use of a regenerative cycle for tungsten­halogen lamps. DOE understands

that other regenerative cycles also may be possible for other filament materials and are

considered technologically feasible. However, as noted above, DOE has screened out the

use of novel filament materials on the basis of the second and third screening criteria.

Because use of the non­tungsten­halogen regenerative cycles would depend on

incorporating a non­tungsten filament, DOE is screening out such cycles from

consideration based on the same two criteria. DOE believes that it would not be

practicable, and maybe not even possible, to manufacture novel filament materials lamps

with associated regenerative cycles on the scale necessary to serve the relevant market at

the time of the effective date of an amended standard. Also, the use of other filament

materials, and therefore their associated regenerative cycles, may have an adverse impact

on utility. In addition, because this technology has not been incorporated into

commercially available products, DOE is unable to assess whether it will have adverse

impacts on consumer health or safety. Therefore, DOE will not consider non­tungstenhalogen regenerative cycles as a design option for improving the efficacy of IRL.

4.2.2.6 Infrared Phosphor Glass Coating

When used as a coating on the bulb surface, infrared phosphors harvest the

emitted infrared energy and convert it to visible light, potentially increasing lamp

efficacy. Because patents on such infrared phosphor coatings exist, DOE believes that

this technology option is technologically feasible. However, DOE was unable to locate

any data on the incorporation of infrared phosphor coatings into commercially available

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products. Because using infrared phosphor coatings in IRL may require retooling of the

manufacturing process, DOE believes that it would not be practicable to manufacture this

technology on the scale necessary to serve the relevant market at the time of the effective

date of an amended standard. Therefore, DOE screened out this option based on the

second criterion. It is also impossible to assess whether the technology will have adverse

impacts on utility to consumers, availability, or consumer health or safety. Therefore,

DOE will not consider infrared phosphor coatings as a design option for improving the

efficacy of IRL.

4.2.2.7 Integrally Ballasted Low Voltage Lamps

Incandescent filaments that are designed to operate at a lower voltage are both

shorter in length and thicker in cross­sectional area than incandescent filaments designed

to operate at a line voltage from 115 to 130V. Increasing the thickness of the filament

can improve its efficacy by allowing the lamp to operate at higher temperatures.

Therefore, using an integral ballast allows the efficacy of a lamp to increase by operating

its filament at a lower voltage (e.g., 12 volts) than standard U.S. household line voltage

1 (i.e., 120 volts). Although this technology is commercially available in Europe and

elsewhere in the world where the standard household line voltage is 220­240 volts, DOE

is unaware of any commercially available products or prototypes of this technology

option that operate on U.S. household line voltage of 120 volts. Accordingly, DOE is

screening out integrally ballasted low voltage lamps based on the first criterion,

technological feasibility. Therefore, DOE will not consider integrally ballasted low

voltage lamps as a design option for improving the efficacy of IRL.

4.2.2.8 Trihedral Corner Reflectors

Trihedral corner reflectors incorporated into the cover glass of IRL have the

potential to increase lamp efficacy by redirecting infrared radiation back onto the

filament. Because patents on trihedral corner reflectors exist, DOE believes that this

technology option is technologically feasible. However, DOE was unable to locate any

data on the incorporation of this technology into commercially available products. Using

trihedral corner reflectors, which entail an additional disc requiring external fabrication

and installation in the lamp, may necessitate manufacturing techniques not currently

available for mass production. For this reason, DOE believes that it would not be

practicable to implement the new manufacturing technique for this technology on the

scale necessary to serve the relevant market of IRL at the time of the effective date of an

amended standard. Therefore, DOE screened out this option based on the second

criterion. It is not possible to assess whether the technology will have adverse impacts on

utility to consumers, availability, or consumer health or safety. Therefore, DOE will not

consider trihedral corner reflectors as a design option for improving the efficacy of IRL.

Philips Electronics Press Release (2007). Available at

http://www.lighting.philips.com/gl_en/news/press/product_innovations/archive_2007/press_new_mastercla

ssic_lamp.php.

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4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED OUT

The following tables summarize the technology options DOE screened out from

further consideration and note the screening criteria.

Table 4.3.1 GSFL Technology Options Screened Out of the Analysis

Design Option Excluded Screening Criteria

Multi­Photon Phosphors Technological feasibility

Practicability to manufacture, install, and service

Table 4.3.2 IRL Technology Options Screened Out of the Analysis

Design Option Excluded Screening Criteria

Microcavity Filaments Product utility to consumers

Practicability to manufacture, install, and service

Novel Filament Materials Practicability to manufacture, install, and service; product

utility to consumers

Crystallite Filament Coatings Practicability to manufacture, install, and service

Luminescent Gas Technological feasibility

Non­Tungsten­Halogen Regenerative

Cycles

Practicability to manufacture, install, and service

Product utility to consumers

Infrared Phosphor Glass Coating Practicability to manufacture, install, and service

Integrally Ballasted Low Voltage Halogen Technological feasibility

Trihedral Corner Reflectors Practicability to manufacture, install, and service

4.4 REMAINING TECHNOLOGIES

After screening out those technologies in accordance with the policies set forth in

10 CFR Part 430, Subpart C, Appendix A, (4)(a)(4) and 5(b), DOE is considering the

design options in the following list as viable means for improving efficacy. The market

and technology assessment (Chapter 3) provides a detailed description of these design

options.

4.4.1 General Service Fluorescent Lamps Design Options

• Highly Emissive Electrode Coatings

• Higher­Efficiency Lamp Fill Gas Composition

• Higher­Efficiency Phosphors

• Glass Coatings

• Higher­Efficiency Lamp Diameter

4.4.2 Incandescent Reflector Lamps Design Options

• Higher­Temperature Operation

• Thinner Filaments

• Efficient Filament Coiling

• Efficient Filament Orientation

• Higher­Efficiency Inert Fill Gas

• Tungsten­Halogen Lamps

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• Higher­Pressure Tungsten Halogen Lamps

• Infrared Glass Coatings (thin­film)

• Higher­Efficiency Reflector Coatings

• Efficient Filament Placement

DOE will consider these options in the engineering analysis. As discussed in

Chapter 5, DOE based its engineering analysis to the greatest extent possible on

commercially available products, which incorporate one or more of these design options.

By doing this, DOE uses catalog data to determine both prices and performance attributes

more efficacious lamps.

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REFERENCES

1 U.S. Department of Energy Office of Building Technologies. U.S. Lighting Market

Characterization, Volume II: Energy Efficient Lighting Technology Options. September,

2005. Washington, D.C.

<www.eere.energy.gov/buildings/info/documents/pdfs/ee_lightingvolII.pdf>

2 Ibid.

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