CHAPTER 4. SCREENING ANALYSIS

TABLE OF CONTENTS

4.1 INTRODUCTION ........................................................................................................... 4-1
4.2 SCREENED-OUT TECHNOLGIES............................................................................... 4-2
4.2.1 General Service Fluorescent Lamp Screened-Out Technologies ........................4-2
4.2.1.1 Multi-Photon Phosphors .......................................................................... 4-2
4.2.2 Incandescent Reflector Lamp Sc reened-Out Technologies.................................4-2
4.2.2.1 Microcavity Filaments ............................................................................. 4-2
4.2.2.2 Novel Filament Materials ........................................................................ 4-3
4.2.2.3 Crystallite Filament Coatings .................................................................. 4-3
4.2.2.4 Luminescent Gas...................................................................................... 4-4
4.2.2.5 Non-Tungsten-Halogen Rege nerative Cycles..........................................4-4
4.2.2.6 Infrared Phosphor Glass Coating.............................................................4-4
4.2.2.7 Trihedral Corner Reflectors ..................................................................... 4-5
4.3 SUMMARY OF TECHNOLOGY OP TIONS SCREENED OUT.................................. 4-5
4.4 REMAINING TECHNOLOGIES ................................................................................... 4-6
4.4.1 General Service Fluorescent Lamps Design Options .......................................... 4-6
4.4.2 Incandescent Reflector Lamps Design Options................................................... 4-6
REFERENCES ..................................................................................................................... .......4-8

LIST OF TABLES

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

4-iCHAPTER 4. SCREENING ANALYSIS

4.1 INTRODUCTION

This chapter discusses th e U.S. Departme nt of Energy’s (DOE) screening analysis of the technology options identified for ge neral service fluorescent lamps (GSFL) and incandescent reflector lamps (IRL). As di scussed in chapter 3, the Market and Technology Assessment, DOE consults with industry, technical experts, and other interested parties in devel oping a list of technology opti ons for consideration. The purpose of the screening analysis is to evalua te 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 whet her a standard is tec hnologically feasible and economically justified, Appendix A to Subpart C of Title 10, Code of Federal Regulations, Part 430 (10 CFR Part 430), “Pro cedures, Interpretati ons, and Policies for
Consideration of New or Revised Ener gy Conservation Standards for Consumer Products” (the Process Rule) sets forth proce dures 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 pres cribing or amending an energy efficiency standard. In particular, sectio ns 4(b)(4) and 5(b) of the Pr ocess Rule provide guidance to DOE for determining which design options ar e unsuitable for further consideration:

1. Technological feasibility. DOE will consider technol ogies incorporated in commercial products or in working protot ypes to be techno logically feasible.

2. Practicability to manufacture, install, and service. If mass production and
reliable installation and se rvicing of a technology in commercial products could be achieved on the scale necessary to serv e the relevant market at the time the standard comes into effect, then DOE w ill 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 signifi cant adverse impact on the utility of the product to significant subgroups of consumers, or would result in the unavailability of any covered product t ype with performance characteristics (including reliability), features, size s, capacities, and volumes that are substantially the same as products generall y 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.

4-1Section 4.2 discusses the technology options D OE 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 t echnologies that DOE screen ed out, having considered the following four factors: (1) technologica l f easibility; (2) practi cability to manufacture, install, and service; (3) adverse impacts on pr oduct utility to consum ers; and (4) adverse impacts on health or safety.

4.2.1 General Service Fluorescent Lamp Screened-Out Technologies

DOE has screened out the following tec hnologies in its analyses of GSFL. Although these technologies were not considered in the s ubsequent analyses, DOE does not discourage their use by m anufacturers. These techno logies may be capable of reducing energy consumption or providing additional benefits to consumers, even though they do not currently meet the re quirements for DOE’s consideration.

4.2.1.1 Multi-Photon Phosphors

Theoretically, the use of m ulti-photon phos phors, 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 of power. However, development of this tec hnology remains in the research phase and DOE is unaware of any prototypes or comm ercialized products that incorporate multiphoton phosphors. 1 Thus, DOE screened out this technology option based on the first criterion, technological feasibilit y. 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 se rvice this technology on the sc ale necessary to serve the
relevant market at the time of the effective date of an amended st andard. 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 multi-photon 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 technol ogies for IRL. Although DOE di d 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 m icrocavities on the incande scent lamp filament, it is theoretically possible to increase a lamp’s emissivity, a nd therefore its efficacy. The market and technology assessment (chapter 3) notes that Sandia National Laboratories researchers examined microcavity resonance in a tungs ten photonic lattice and DOE found multiple

4-2patents referencing this technology. Since re search prototypes of microcavity filaments do exist, DOE determined that this tec hnology option is technologically feasible. However, research indicates that materials patterned at the submicron level may experience problems with stability. 2 Because such instability could negatively affect lamp lifetime, DOE believes the technology is not yet practical to implement on a large scale. For this reason, DOE screened out this technology option based on the third criterion, impacts on product utility to c onsumers. DOE is also unaware of any commercialized lamps that incorporate micro cavity filaments, and is concerned that mass-manufacturing techniques for this technology would be problematic. For this reason, DOE does not believe that this technol ogy would be practicab le 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 th is technology will have adverse impacts on consumer health or safety.

4.2.2.2 Novel Filament Materials

Novel filament m aterials such as nitrid es and carbides have the potential to improve lamp efficacy by emitting more light in the visible spectrum at a given temperature than traditional tungsten fila ments. Because several patents on such filaments exist, DOE believes that this t echnology option is tec hnologically feasible. However, DOE is unaware of any lamps ava ilable 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 IR L would require furthe r research, as would making such lamps practical for general servi ce applications. DOE believes that it would not be practicable to manufacture this t echnology on the scale necessary to serve the
relevant market at the time of the effective da te of an amended sta ndard. 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 filam ent coatings, which are oxide-covered micron or sub-micron 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 feasib le. However, DOE was unable to locate any data on the incorporation of crystallite filament coati ngs into prototype or commercially available products. Using crystallite filament coatings may require additional manufacturing techniques, such as chemical vapor deposit ion. DOE understands that these techniques are not in use in the mass-production of IR L. 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 da te of an amended standard. DOE screened out this option based on the sec ond criterion. It is also not possible to assess whether this technology will have adverse impacts on utility to consumers, availability, or consumer

4-3health or safety. Therefore, DOE will not c onsider crystallite filament coatings as a design option for improving the efficacy of IRL.

4.2.2.4 Luminescent Gas

Lum inescent 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 produc ts 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 manufactur e, install, and service this technology on the scale necessary to serve the relevant marketat 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 o f filament evapor ation 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 inca ndescent lamps while maintaining a useful service life. The ma rket and technology assessment (chapter 3) discusses the use of a regene rative cycle for tungsten-halogen 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 non-tungsten-halogen regenerative cycles would depend on incorporating a non-tungsten filament, DOE is screening out such cycles from
consideration based on the same two criter ia. 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 scal e necessary to serve the relevant market at
the time of the effective date of an amende d standard. Also, the use of other filament materials, and therefore their associated rege nerative cycles, may have an adverse impact on utility. In addition, because this t echnology has not been incorporated into commercially available products, DOE is unabl e to assess whether it will have adverse impacts on consumer health or safety. Th erefore, DOE will not consider non-tungstenhalogen 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 phosph ors harvest the emitted infrared energy and convert it to vi sible light, potentially increasing lamp efficacy. Because patents on such infrared phosphor coatings exist, DOE believes that this technology option is techno logically feasible. However, DOE was unable to locate any data on the incorporation of infrared phosph or coatings into commercially available

4-4products. Because using infrared phosphor coatings in IRL may require retooling of the manufacturing process, DOE believes that it wo uld not be practicable to manufacture this technology on the scale necessary to serve the rele vant 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 co atings as a design option for improving the efficacy of IRL.

4.2.2.7 Trihedral Corner Reflectors

Trihedral co rner reflectors incorporated into the cover glas s of IRL have the potential to increase lamp efficacy by redi recting infrared radiation back onto the filament. Because patents on trihedral corner reflectors exist, DOE believes that this technology option is technologica lly 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 a dditional disc requiring external fabrication
and installation in the lam p, may necessitate manufacturi ng techniques not currently available for mass production. For this re ason, DOE believes that it would not be practicable to implement the new manufactur ing technique for this technology on the scale necessary to serve the rele vant market of IRL at the time of the effective date of an amended standard. Therefore, DOE scr eened out this option based on the second criterion. It is not possible to assess whet her 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 de sign option for improving the efficacy of IRL.

4.3 SUMMARY OF TECHNOLOGY OPTIONS SCREENED OUT

The following tables summarize the tec hnology options DOE screened out from
further consideration and not e the screening criteria.

Table 4.3.1 GSFL Technology Option s Screened Out of the Analysis Design Option Excluded Screening Criteria Multi-Photon Phosphors Technological feasibility Practicability to manufacture, install, and service

4-5Table 4.3.2 IRL Technology Option s 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 Non-Tungsten-Halogen Regenerative Cycles Practicability to manufacture, install, and service Product utility to consumers Infrared Phosphor Glass Coating Practicability to manufacture, install, and service
Trihedral Corner Reflectors Practicability to manufacture, install, and service

4.4 REMAINING TECHNOLOGIES

Af ter 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) provi des a detailed descrip tion of these design options.

4.4.1 General Service Fluorescent Lamps Design Options

 Highly Em issive Electrode Coatings

 Higher-Efficiency Lamp Fill Gas Composition

 Higher-Efficiency Phosphors

 Glass Coatings

 Higher-Efficiency Lamp Diameter

4.4.2 Incandescent Reflector Lamps Design Options

 Higher-Tem perature Operation

 Thinner Filaments

 Efficient Filament Coiling

 Efficient Filament Orientation

 Higher-Efficiency Inert Fill Gas

 Tungsten-Halogen Lamps

 Higher-Pressure Tungsten Halogen Lamps

 Infrared Glass Coatings (thin-film)

 Higher-Efficiency Reflector Coatings

 Integrally-Ballasted Low-Voltage Lamps

 Efficient Filament Placement

DOE will consider these options in the engineering analysis. As discussed in chapter 5, DOE based its engineering analys is to the greatest extent possible on commercially available products, which incorpor ate one or more of these design options.

4-6By doing this, DOE uses catalog data to determ ine both prices and pe rformance attributes more efficacious lamps.

4-74-8 REFERENCES

1 U.S. Department of Energy Office of Building Technologies. U.S. Lighting Market Characterization, Volume II: Energy Efficient Lighting Tech nology Options. September, 2005. (Last accessed July 1, 2009).

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

2 Ibid.