4

- i CHAPTER 4. SCREENING ANALYSIS

TABLE OF CONTENTS

4.1 INTRODUCTION ........................................................................................................... 4 -1 4.2 SCREENED OUT TECHNOLOGIES ............................................................................ 4 -2 4.2.1 General Service Fluorescent Lamps .................................................................... 4 -2 4.2.1.1 Multi-Photon Phosphors .............................................................. 4-2 4.2.2 Incandescent Reflector Lamps ............................................................................. 4 -2 4.2.2.1 Novel Filament Materials ............................................................ 4-2 4.2.2.2 Microcavity Filaments ................................................................. 4 -3 4.2.2.3 Crystallite Filament Coatings ...................................................... 4-3 4.2.2.4 High Reflectance Filament Supports ........................................... 4 -3 4.2.2.5 Non-Tungsten -Halogen Regenerative Cycles.............................. 4-4 4.2. 2.6 Higher Efficiency Gold Reflector Coatings ................................. 4 -4 4.2.2.7 Permanent Infrared Reflector Coating Shroud ............................ 4-4 4.2.2.8 Infrared Phosphor Glass Coating ................................................. 4 -5 4.2.2.9 Ultraviolet Phosphor Glass Coating............................................. 4 -5 4.2.2.10 Corner Reflectors .................................................................... 4 -5 4.2.2.11 Electron Stimulated Luminescence ......................................... 4 -5 4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED O UT .................................. 4 -6 4.4 REMAINING TECHNOLOGI ES ................................................................................... 4 -6 4.4.1 General Service Fluorescent Lamp Design Options ............................................ 4 -6 4.4.2 Incandescent Reflector Lamp Design Options .................................................... 4 -7 REFERENCES ............................................................................................................................ 4 -8

LIST OF TABLES

Table 4.3.1 GSFL Technology Options Screened Out of the Analysis ........................... 4-6 Table 4.3.2 IRL Technology Options Screened Out of the Analysis .............................. 4-64

- 1 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 (GSFLs) and in c andescent reflector lamps (IRLs). As discussed in chapter 3 of this preliminary technical support document (TSD), 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 and determine which to consider further and which to screen out.

Section 325(o)(2) of the Energy Policy and Conservation Act (EPCA) provides that a ny 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 (CFR), Part 430, “Procedures, I nterpretations, and Policies for Consideration of New or Revised Energy Conservation Standards for Consumer Products” (the Process Rule) sets forth procedures to guide DOE in i ts consideration and promulgation of new or revised efficiency standards. These
pr ocedures 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 technology options are unsuitable for fur ther consideration:

1. Technological feasibility. DOE will consider technologies incorporated in commercial ly available products or in working prototypes to be technologically feasible.

2. Practicability to manufacture, install, and service. If mass production of a technology and reliable installation and servicing of the technology could be

a chieved on the scale necessary to serve the relevant market at the time the standard requires compliance, 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
g enerally available in the United States at the time, it will not further consider this technology.4

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4. Adverse impacts on health or safety. If DOE determines that a technology will ha ve significant adverse impacts on health or safety, it will not further consider this technology.

Section 4.2 of this chapter discusses the technology options DOE screened out fr om further consideration. Section 4.3 summarizes those options. Section 4.4 lists the remaining technology options not screened out and considered as design options in this
pr eliminary analys is

. The market and technology assessment (see chapter 3 of this preliminary technical support document [TSD]) discusses in detail all technology options analyzed in this preliminary analysis.

4.2 SCREENED OUT TECHNOLOGIES

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 or product availability; and (4) adverse impacts on health or safety.

4.2.1 General Service Fluorescent Lamps

4.2.1.1 Multi-Photon Phosphors

Theoretically, the use of multi-photon phosphors, or quantum-splitting 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 o f power. Researchers at Georgia Tech were issued a patent for an oxide-based phosphor dope d with praseodymium and atoms of at least one activator that produces two visible li ght photons from a single ultraviolet light photon. 1 However, development of this technology for use in lighting products remains in the research phase and DOE is

una ware of any prototypes or commercialized products that incorporate multi-photon phosphors. 2 Further, researchers have identified technical drawbacks to this technology such as light color output, color stability, and phosphor lifetime. 3 Thus , DOE screened out this technology option based on the first criterion, technological feasibility, and will not consider multi-photon phosphors as a design option for improving the efficacy of GSFLs.

4.2.2 Incandescent Reflector Lamps

4.2.2.1 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 patents on such filaments exist, 4

5 DOE believes that this technology option is technologically feasible. However, DOE is unaware of any commercially available lamps that incorporate such filaments and ther efore, it is unclear that this technology is practicable to manufacture on the scale necessary to serve the relevant market at this time. Furthermore, DOE understands that issues, such as prohibitive brittleness of the filament, limit implementation of this4

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technology and could potentially negatively impact its utility to consumers. Therefore, DOE screened out novel filament materials on the basis of the second criterion, practicability to manufacture, and the third criterion, potential impacts on utility to
consumers, and will not consider novel filament materials as a design option for improving the efficacy of IRLs.

4.2.2.2 Microcavity Filaments By fabricating microcavities on the incandescent lamp filament, it is theoretically possible to increase a lamp’s emissivity, and therefore its efficacy. Sandia National Laboratories researchers examined microcavity resonance in a tungsten photonic lattice 6 and DOE found multiple patents referencing this technology. 7 8 Because prototypes of microcavity filaments do exist, DOE determined that this technology option is technologically feasible. However, DOE is unaware of any commercially available lamps that incor porate microcavity filaments and therefore, it is unclear that this technology is practicable to manufacture on the scale necessary to serve the relevant market at this time. Additionally, research indicates that materials patterned at the submicron level may experience problems with stability. 9 Therefore, DOE screen ed out microcavity filaments based on the second criterion, practicability to manufacture, and third criterion, adverse im pacts on consumer utility, and will not consider filaments with microcavities as a de sign option for improving the efficacy of IRLs.

4.2.2.3 Crystallite Filament Coatings DOE screened out crystallite filament coatings, which are oxide-covered micron or submicron crystallites composed of thorium, tantalum, or niobium. These coatings can be used to increase the light emissivity of a lamp’s filament. Because patents on such filame nt coatings exist, 10 DOE b elieves that this technology option is technologically feasible. However, DOE i s unaware of any commercially available lamps that incorporate crystallite filament coatings. Further, using crystallite filament coatings may require

a dditional manufacturing techniques, such as chemical vapor deposition. DOE understands that these techniques are not in use in the mass production of IRLs. Hence, DO E does not consider this a technology that is practicable to manufacture on the scale necessary to serve the relevant market at this time. Therefore, DOE screened out this option based on the second criterion, practicability to manufacture, and will not consider crystallite filament coatings as a design option for improving the efficacy of IRLs.

4.2.2.4 High Reflectance Filament Supports

Filament supports can have a reflective face that redirects light to a filament, another reflector, or radially outward. The filament supports could also include grooves, a coating with a high emissivity to increase heat dissipation, or be formed of a porous ceramic material to increase efficiency. However, halogen capsules have not incorporated these structures due to potential efficacy losses. Because this technology is still in the patent application stage, 11 DOE screened out high reflectance filament supports based on the first criterion, technological feasibility. Thus, DOE will not consider high reflectance filament supports as a design option for improving the efficacy of IRLs.4

- 4 4.2.2.5 Non-Tungsten-Halogen Regenerative Cycles

The regenerative cycle of filament evaporation and redeposition can be used to
g reatly 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. DOE understands that other regenerative cycles also

ma y be possible for non-tungsten filament materials and patents indicate they are technologically feasible. 12 However, as noted in section 4.2.2.1 , DOE has screened out the use of novel filament materials on the basis of the second and third screening criteria. Because use of the non-tungsten-halogen regenerative cycles would depend on incor porating a non -tungsten filament, DOE screen ed out such cycles from consideration based on the same two criteria, practicability to manufacture and potential adverse impacts on utility to consumer. Therefore, DOE will not consider non-tungsten-halogen

re generative cycles as a design option for improving the efficacy of IRLs.

4.2.2.6 Higher Efficiency Gold Reflector Coatings Gold is one type of higher efficiency reflector coating that is extremely reflective and has the potential to increase the amount of directed light, an d therefore the efficacy, of IRLs. Because a patent on the use of gold reflector coatings exists, 13 14 DOE has determined that this technology option is technologically feasible. However, DOE found that gold reflectivity diminishes at and below blue-green wavelengths, which may d ecrease the color quality of light, 15 thereby impacting product utility. Further, goldreflector coatings have thus far been used mainly in lamps that produce infrared and nearinfrared light ( e .g. , heat lamps or lamps intended to change the color of light, such as those used for photography purposes). Therefore, use of these reflector coatings may not be suitable for general lighting applications. Hence, DOE screen ed out high efficiency gold reflector coatings based on the third criterion, adverse impact on product utility, and will not consider higher efficiency gold reflector coatings as a design option for improving the efficacy of IRLs. However, DOE did not screen out other higher efficiency reflector coatings, such as aluminum and silver, because they do not have an adverse impact on product utility and meet DOE’s screening criteria. Therefore, DOE considers higher efficiency reflector coatings, with the exception of gold reflector coatings, as design options for improving the efficacy of IRLs.

4.2.2.7 Permanent Infrared Reflector Coating Shroud

Infrared reflector coatings on halogen capsules allow visible light to pass through the glass envelope, while reflecting the infrared energy back to the filament. As this coating must be replaced whenever the lamp reaches end of life, it represents a significant component of manufacturing costs. A permanent shroud with infrared reflector coating would therefore increase efficiency while also reducing manufacturing costs. However, be cause this technology is still in the patent application stage, 16 DOE screened out permanent infrared reflector coating shrouds based on the first criterion, technological feasibility. Thus, DOE will not consider permanent infrared reflector coating shrouds as a design option for improving the efficacy of IRLs.4

- 5 4.2.2.8 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, 17 DOE has determined that this technology option is technologically feasible. However, DOE i s

una ware of commercially available lamps that incorporate infrared phosphor glass

c oatings. Hence, DOE does not consider this a technology that is practicable to manuf acture on the scale necessary to serve the relevant market at this time. Therefore, DOE screened out this option based on the second criterion, practicability to manufacture, and will not consider infrared phosphor coatings as a design option for improving the efficacy of IRLs.

4.2.2.9 Ultraviolet Phosphor Glass Coating Similar to infrared phosphor glass coating, when used as a coating on the bulb surface, ultraviolet phosphors absorb ultraviolet radiation and convert it to visible light. Because patents on the incorporation of ultraviolet phosphor glass coatings exist, DOE has determined that this technology option is technologically feasible. 18 19 However, DOE is unaware of commercially available lamps that use ultraviolet phosphor glass

c oatings. Hence, DOE does not consider this a technology that is practicable to manuf acture on the scale necessary to serve the relevant market at this time. Therefore, DO E screen ed out this option based on the second criterion, practicability to manufacture, and will not consider ultraviolet phosphor glass coatings as a design option for improving the efficacy of IRLs.

4.2.2.10 Corner Reflectors Corner reflectors incorporated into the cover glass of IRLs have the potential to incr ease lamp efficacy by redirecting infrared radiation back onto the filament. Because patents on trihedral and cubic corner reflectors exist, 20 21 DOE believes that this technology option is technologically feasible. However, DOE is unaware of any commercially available lamp that incorporates corner reflectors. Further, using corner reflectors, which entails an additional disc requiring external fabrication and installation in t he lamp, may necessitate manufacturing techniques not currently available for mass production. Hence, DOE does not consider this a technology that is practicable to manuf acture on the scale necessary to serve the relevant market at this time. Therefore, DOE screened out this option based on the second criterion, practicability to manufacture, and will not consider corner reflectors as a design option for improving the efficacy of IRLs.

4.2.2.11 Electron Stimulated Luminescence When struck by the electrons thermally ejected from a lamp’s filament,

c athodoluminescent phosphors emit visible light. Because a patent on the use of electron sti mulated luminescence exists, 22 DOE has determined that this technology option is technologically feasible. However, DOE is unaware of any commercially available lamps that incorporate electron stimulated luminescence. Hence, DOE does not consider this a
tec hnology that is practicable to manufacture on the scale necessary to serve the relevant4

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market at this time. Therefore, DOE screen ed out this technology option on the basis of the second criterion, practicability to manufacture, and will not consider electron stimulated luminescence as a design option for improving the efficacy of IRLs.

4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED OUT

The fo llowing tables summarize the technology options DOE is considering screening out and the associated screening criteria.

Table 4.3. 1 GSFL Technology Options Screened Out of the Analysis

Design Option Excluded Screening Criteria Multi

- Photon Phosphors Technological feasibility

Table 4.3. 2 IRL Technology Options Screened Out of the Analysis

Design Option Excluded Screening Criteria

Novel Filament Materials Practicability to manufacture, install, and service Product utility to consumers
Microcavity Filaments Practicability to manufacture, install, and service P roduct utility to consumers Crystallite Filament Coatings Practicability to manufacture, install, and service High Reflectance Filament Supports Technological feasibility

Non

- Tungsten

- Halogen Regenerative Cycles Practicability to manufacture, install, and service Product utility to consumers Higher Efficiency Gold Reflector Coatings Product utility to consumers Permanent Infrared Reflector Coating Shroud Technological feasibility Infrared Phosphor Glass Coating Practicability to manufacture, install, and service Ultraviolet Phosphor Glass Coating Practicability to manufacture, install, and service Corner Reflectors Practicability to manufacture, install, and service Electron Stimulated Luminescence Practicability to manufacture, install, and service

4.4 REMAINING TECHNOLOGI ES After screening out those technologies in accordance with the policies set forth in 10 CF R 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. These design opti ons are being utilized in commercially available lamps and have demonstrated that they are technologically feasible, practicable to manufacture, install, and service, and do not result in adverse impacts on product utility/availability or health and safety. The

mar ket and technology assessment (see chapter 3 of this TSD) provides a detailed de scription of these design options.

4.4.1 General Service Fluorescent Lamp Design Options

 Highly Emissive Electrode Coatings

 Higher Efficiency Lamp Fill Gas Composition

 Higher Efficiency Phosphors

 Glass Coatings

 Higher Efficiency Lamp Diameter4

- 7

4.4.2 Incandescent Reflector Lamp Design Options

 Higher Temperature Operation

 Thinner Filaments

 Efficient Filament Placement

 Efficient Filament Orientation

 Efficient Filament Coiling

 Higher Efficiency Inert Fill Gas

 Higher Pressure Tungsten-Halogen Lamps

 Infrared Glass Coatings

 Higher Efficiency Reflector Coatings (with the exception of gold reflector

c oatings)

 Integrally Ballasted Low Voltage Lamps

DOE will consider the se options in the engineering analysis as a viable means for improving lamp efficacy.4

- 8 REFERENCES

1 Do, Young-rag (Seoul, KR); Park, Do-hyung (Suwon-city, KR); Park, Woun-jhang (Boulder, CO, US); Summers, Christopher J. (Dunwoody, GA, US); Yang, Hong-guen (Suwon-City, KR). (2003). U.S. Patent No. 6669867. Washington, DC: U.S. Patent and Trademark Office

.

2 U.S. Department of Energy Office of Building Technologies. U.S. Lighting Market Characterization, Volume II: Energy Efficient Lighting Technology Options. September, 2005. (Last accessed October 24, 2012 ).

< http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/ee_lighting_vol2.pdf >

3 Scholand, Michael. (2012). Max Tech and Beyond: Fluorescent Lamps. Lawrenc e Berkeley National Laboratory. LBNL Paper LBNL-5403E. (Last accessed October 22, 2012) < http://escholarship.org/uc/item/9569025t >

4 Van Thyne, Ray J., inventor; 1992 Sep. 15. Incandescent lamp filament incorporating hafnium. United States patent 5,148,080.

5 Johansen, H. A. et al., inventor; 1968 Oct. 8. Incandescent lamp with a refractory metal carbide filament. United States patent 3,405,328.

6 Ibid.

7 Jaffe, Steven et al., inventor; 1999 Sep. 21. Incandescent microcavity lightsource having filame nt spaced from reflector at node of wave emitted. United States patent 5,955,839.

8 Liu, Xinbing et al., inventor; 2006 May 9 . Method for apparatus for forming discrete microcavities in a filament wire using microparticles. United States patent 7,040,130.

9 U.S. Department of Energy Office of Building Technologies. U.S. Lighting Market Characterization, Volume II : Energy Efficient Lighting Technology Options. September, 2005. (Last a ccessed October 24, 2012). <http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/ee_lighting_vol2.pdf>

10 Bigio, Laurence et al., inventor; 1995 Feb. 14. Incandescent lamp filament with surface crystallites and method of formation. United States patent 5,389,853

11 Cunningham, David W., inventor; 2012 Aug. 28. Incandescent lamp incorporating reflective filament supports and method for making it. United States patent 8,253,309 B2.

12 Van Thyne, Ray J., inventor; 1992 Sep. 15. Incandescent lamp filament incorporating ha fnium. United States patent 5,148,080.4

- 9 13 Anderson, Norman C. et al., inventor; 1971 Nov. 9. Gold-coated reflector. United States patent 3,618,193.

14 Walsh, Peter J. et al., inventor; 1988 Mar. 1. Energy-eficient incandescent reflector lamp. United States patent 4,728,848.

15 Anderson, Norman C. et al., inventor; 1971 Nov. 9. Gold-coated reflector. United States patent 3.618,193.

16 Cunningham, David W., inventor; 2012 Sep. 18. Incandescent illumination system incorporating an infrared-reflective shroud. United States patent 8,267,547 B2.

17 Vincent Jr., Charles, inventor; 1973 Nov. 20. Solid state lamp having visible-emitting phosphor a t edge of infrared-emitting element. United States patent 3,774,086.

18 Thorington, Luke, inventor; 1960 Jan. 5. Electric lamp. United States patent 2,920,222

19 Patton, R.J., et al., inventor; 1992 June 2. Fluorescent incandescent lamp. United States patent 5,118,985

20 Walsh, Peter J., inventor; 1989 Mar. 28. Corner cube array for use in incandescent lamps. Unit ed States patent 4,816,714.

21 Nilssen, Ole K., inventor; 1986 Sep. 16. Incandescent lamp with dichroic trihedral corner reflectors. United States patent 4,612,473.

22 Thorington, Luke, inventor; 1956 Aug. 14. Combination light source. United States patent 2,759,119.