Electrodeless Lamps

RPI, or Rensselaer Polytechnic Institute, have this article on induction / electrodeless lamps from 1998. The original post can be found here

Electrodeless Lamps
When the fluorescent lamp first appeared in lamp catalogs in 1938, the lighting community saw it as a novelty source for producing colored light. Today, fluorescent lamps light over 50% of the building floorspace in the North America. Four companies hope that their electrodeless lamps can pull off a similar feat.

Philips Lighting's QL lamp system
In 1991, Philips introduced the QL in Europe. But how many specifiers realize that the QL has been available in North America since 1992? It's never been listed in Philips' North American catalog. "All we need to fill orders is a purchase order," says Lloyd Chapman, the product manager handling the QL for Philips' North American division.

In Europe, Philips sells the QL with several choices of luminaires. However, Philips doesn't offer QL luminaires in North America. Chapman believes that the QL could catch on here if it were packaged with a luminaire. Tom Heelan, CEO of WILA Lighting, agrees. "It's an OEM product...Philips can't sell this. We [luminaire manufacturers] have to do it for them." (An OEM is an original equipment manufacturer, a company that buys parts from manufacturers, puts them together, and sells the systems.)

Philips initially marketed the QL only to luminaire manufacturers. Although they liked the technology, the manufacturers did not market the QL because of its high cost and the lack of demand. Philips is now developing new marketing strategies. "We want to work with the marketplace to establish trial installations," says Chapman.

Luminaire manufacturers and specifiers are responding. In early 1995, Hadco, a division of Genlyte, worked with American Electric Power, a utility in Cleveland, Ohio, to set up a trial QL installation with outdoor post-top fixtures. And WILA Lighting joined with Philips and the municipality of Philadelphia to propose a test installation of over 100 QL systems to the Urban Consortium Energy Task Force.

Intersource Technology, Inc.'s E-Lamp
In the late 1980s, Intersource licensed the technology for the E-Lamp from Diablo Research Corporation (which presently has an engineering relationship with Intersource). After Intersource made a product announcement in June 1992, the E-Lamp caused a stir in major broadcast and print media. But where's the lamp?

Pierre Villere, founder and chairman of the board of Intersource, explains. "Intersource's efforts on what we call the A-Line replacement took longer and cost more than expected." More significant, feels Villere, is that in mid-to-late 1993 Intersource saw residential demand-side management programs coming to an end. "This put us in a quandary," says Villere, "because here we were with a product we were very close to taking out of engineering and into manufacturing, yet the programs that fueled the sales of high-efficiency lighting products were evaporating." Intersource felt that the American consumer would not voluntarily spend $10 to $15 on a long-life, high-efficiency product without utility rebates.

Intersource believes the commercial lighting market is more willing to invest in the E-Lamp. Villere notes the widespread acceptance of compact fluorescent lamps (CFLs) as an alternative to incandescent lighting in commercial market. "We want to do the same thing," says Villere. "We want the E-Lamp to become a standard in the industry." The company plans to sell the E-Lamp to OEMs and have them market their products as "E-Lamp Equipped." Intersource does not plan to enter the residential market in the near future.

GE Lighting's Genura
The E-Lamp's publicity elicited a response from GE. In a June 1992 memo to its lighting managers, GE stated that it had been developing and investing in electrodeless induction technology for many years. Two years later, GE introduced the Genura in Europe. "It's a highly successful lamp," says Terry McGowan, manager of application development at GE Lighting. "We cannot meet the demand and have committed every lamp that we manufacture." Because GE has to fill its European orders, the North American market won't see the Genura until the second quarter of 1995 or later. McGowan adds that GE will have samples available and wants to work with specifiers on projects.

GE will market the Genura as a retrofit for the 75-watt R30 lamps that will be eliminated in the U.S. after October 31, 1995 by the Energy Policy Act of 1992. GE is targeting the commercial market in areas such as retail stores and offices.

Fusion Lighting, Inc.'s sulfur lamp
In October 1994, news about Fusion's sulfur lamp spread across the major media and renewed interest in electrodeless technology. The technology behind the sulfur lamps is not new. Fusion Systems Corporation has a 20-year history of manufacturing microwave discharge units that are used for ultraviolet (UV) curing in the semiconductor and printing industries. In 1990, Fusion Systems discovered that sulfur in the gas fill of its units produced light resembling sunlight. Fusion Systems spun off Fusion Lighting in 1993 to develop the sulfur lamp as a commercial light source.

Since mid-1994, sulfur lamp prototypes have appeared in demonstrations. Reflector panels coated with a 3M optical film direct the light of two sulfur lamps at the entrance of the University Hospital in Lund, Sweden. In Washington, D.C., the Smithsonian National Air and Space Museum (NASM) and the Forrestal Building feature light pipes made by A.L. Whitehead Ltd. that distribute light from sulfur lamps.

Fusion is now testing the Solar 1000, a smaller, improved version of the sulfur lamp. Sweden has several Solar 1000s for demonstrations in areas such as a botanical garden, post office, and commercial freezer. Kalle Hashmi, senior advisor to NUTEK (the Swedish National Board for Industrial and Technical Development), says, "We could probably place 500 of the Solar 1000s in the Scandinavian market now, but we can't get enough of them."

Kent Kipling, vice president of operations at Fusion Lighting, acknowledges that the company could sell more lamps now. However, Fusion is not ready to market the lamps. "We just need to make sure that we have everything fully understood and life tested before we get a lot of systems out there," says Kipling. "There's no particular area of concern; we're just being prudent." If Fusion decides to commercialize the Solar 1000, it could appear on the market in the first part of 1996.

How electrodeless lamps stack up
Performance-wise, the four lamps are often compared to CFLs and high-intensity discharge (HID) lamps. The table on p. ii lists their performance characteristics, some which are of particular concern to specifiers.

Electromagnetic interference (EMI). Electrodeless lamps are electronic devices, and like all electronic devices, they can generate EM waves. EMI occurs when unwanted EM signals, which travel through wiring or radiate through the air, interfere with desirable signals. The International Special Committee on Radio Interference (Comit* International Sp*cial des Pertubations Radio*lectriques, or CISPR) develops standards for EMI from lighting devices. CISPR standards are accepted by the European Community. In the U.S., the Federal Communications Commission (FCC) regulates EM emissions in the communication frequencies of 450 kHz to over 960 MHz. Canada also regulates EM emissions over these frequencies. Manufacturers need to comply with FCC regulations to sell products in the U.S. However, manufacturer compliance doesn't assure that EMI won't occur in unregulated frequencies.

The Genura and the QL operate at 2.65 MHz, the European Community's standard for induction lighting. The Genura's reflector provides enough shielding to meet the FCC's EMI requirements for commercial use but not for residential use. GE is seeking FCC approval for residential use of the lamp.

The QL lamp system depends on appropriate luminaire designs to meet shielding requirements. Philips offers to test QL luminaires for OEMs to certify that their products are properly shielded and meet other design requirements.

The E-Lamp operates at 13.56 MHz and does not require external shielding to meet FCC requirements. It is approved for both commercial and residential use.

The sulfur lamp operates at 2.45 GHz for regulatory and economic reasons. That frequency is approved for electronics; for example, microwave ovens operate at 2.45 GHz. And because microwave ovens are popular, magnetron parts are produced in large quantities and are relatively inexpensive. The sulfur lamp hasn't yet been approved by the FCC, but Kipling is not concerned. "The RF shielding limitation is one we're not really worried about. We've got 30,000 [microwave discharge] systems out there right now."

Color. The induction lamps use rare-earth phosphors, giving them color properties similar to those of higher-end fluorescent lamps. The sulfur lamp produces a continuous spectrum similar to that of sunlight; Fusion claims there is virtually no spectral shift over the lamp's life. However, some people have complained about the greenish cast of its light. Kipling says that at the NASM, Fusion used a filter because the museum wanted warmer light. For future versions of the lamp, Fusion plans to adjust the color of the light based on feedback received from the demonstration sites.

Light output and control. Carl Hillmann, a lighting designer with Hillmann, Dibernardo and Associates, echoes a common concern about the QL: "It's not available in large enough wattages...It doesn't put out enough light to find its way into an inaccessible location." This is an issue because Philips promotes the QL for use in areas where maintenance costs are high; often these areas involve high mounting heights. According to Donald Fentress, architectural manager at Hadco, his company is working within this limitation. Hadco produces a post-top luminaire with a refractor globe optically designed to maximize the light output of the QL. The design allows the lamp to be used outdoors at heights of 10« to 12«.

Chapman says that Philips is developing QL systems with higher wattages and higher light output. But induction lamps are fluorescent lamps, so the amount of light they emit is proportional to the surface area of the bulb to which phosphors are applied. Increasing the light output requires an increase in the size of the system. The larger the system, the harder it is to control physically and optically.

Because the QL and E-Lamp's glass bulbs resemble the bulb of a common incandescent A-lamp, they benefit from having a shape familiar to specifiers. The spherical shape also means that reflectors can more effectively control their light output than that of the more linear CFLs. The Genura also benefits by having the familiar shape of an R lamp.

The sulfur lamp produces a large amount of light, making it convenient for remote-source lighting applications. At the NASM, three 90«-long light pipes, each lighted at one end by a single sulfur lamp, replaced 94 HID lamps. Because the sulfur lamp is a small, high-intensity source, luminaires for the lamp need to be designed carefully to control glare and light distribution.

None of the electrodeless lamps are entering the market with dimming capability. However, all are potentially dimmable, and the manufacturers are waiting to see if the market wants a dimmable product.

Efficacy. The efficacies of induction lamps are like those of CFLs or HID lamps of comparable light output. On the other hand, estimates of the Solar 1000's potential efficacy exceed 120 lumens per watt, including ballast losses. Fusion decreased the sulfur lamp's input power - and increased its efficacy - by eliminating the external compressor used to cool the rotating glass ball. The compressor was the system's main source of noise, so Fusion also eliminated a source of complaint. Hashmi believes that replacing the magnetron with advanced solid-state technology may increase the sulfur lamp's efficacy to as much as 300 lumens per watt.

Life. Long life is the most touted feature of electrodeless lamps. Because they have no filament or electrode, they don't fail from sputtering, breakage by shock, or other electrode-related phenomena. Though an induction lamp will fail when its electronics fail, its life is limited primarily by the degradation of phosphors.

Life for induction lamps is often rated in hours to 30% lumen depreciation, the point at which lamps normally need to be changed. The E-Lamp and the QL reach 30% lumen depreciation at 30,000 hours and 60,000 hours, respectively.

GE lists the Genura's life in terms of the industry-standard average rated life (the time it takes for 50% of tested lamps to fail). The Genura claims a 10,000-hour average rated life, which is also its point of 30% lumen depreciation.

Recently, Intersource and Philips recast lamp lives as average rated life, and the results are startling. Intersource claims that the E-Lamp has a lamp life of 50,000 hours, and Philips claims a life of over 100,000 hours for the QL. The Genura's 10,000 hours seems unimpressive by comparison. McGowan explains, "The only thing similar is that they are all based on induction. But the designs of the products are completely different, and they are designed for different applications."

The sulfur lamp's bulb practically has an infinite life because the sulfur and argon in its fill do not react with each other or with the glass. The magnetron limits the sulfur lamp's life. Fusion rated the life of its older prototype at around 10,000 hours. Kipling says that Fusion now uses magnetrons with 15,000- and 20,000-hour lives. Replacing the magnetron with solid-state technology can further extend lamp life.

Cost. If life is the most touted feature of electrodeless lamps, cost is the most touted disadvantage. The OEM cost of the QL is around $200; adding a luminaire brings the system to a market price of $500 to $800. Philips emphasizes the long life and the benefits of installing the QL in areas where maintenance costs are high. Chapman says, "You have to look beyond initial cost of the system and at lifecycle costs instead." Hillmann is doubtful: "It would take a long time to pay that [high initial cost] back, especially when access could be had with a small lift or step ladder, given how much light you get out of the QL right now." Heelan agrees that it may be too expensive in some spaces. "But if you're looking at a municipality or a university," he says, "you're talking long-term, maintained usage. That's where the QL really makes a difference."

Some luminaire manufacturers haven't developed products for the QL because the systems can't compete against lower-cost HID systems. Hadco's luminaire is easily retrofittable. Fentress says, "The unit is designed to allow the customer to buy and use high-pressure sodium now, but tomorrow if the cost effectiveness of the QL is resolved, there would be no problem to switch out the source." Additionally, because replacing a QL is expensive, the QL luminaire needs to be resistant to vandalism. WILA produces QL downlights with nearly unbreakable acrylic lenses.

There's no comment from Fusion on the price of the sulfur lamp, currently made in ones and twos for demonstrations and tests. Kipling notes, "Ultimately, what does it cost to buy an inexpensive microwave oven?" Hillmann, who worked on the original NASM lighting design, thinks, "The Fusion lamp has a lot of potential...But what is the cost of the system that conveys that light?" The light pipes and guides now available are reportedly quite expensive. Hashmi says that some manufacturers are starting to produce less expensive alternatives.

Though the Genura appears successful in Europe, some European specifiers feel that it's too expensive. And those who have heard its U.S. price of around $20 also think that it's expensive. "For the efficacy you get," says Fentress, "you might as well buy a CFL." The E-lamp is similarly priced, but it will be packaged with luminaires whose prices are unknown at this time.

Barriers to a bright future
"The barrier [of initial cost] is what the buying decisions are going to be based on in the U.S., and the buying decisions in Europe and Asia, quite frankly, appear to be very different," observes Kipling. Both Kipling and Villere think that cost is the major, if not only, barrier to the use of their lamps in the U.S. As with many new products, electrodeless lamps will have to break the vicious circle of demand and cost. Philips runs into a sole-sourcing problem with the QL: no one besides Philips makes a QL-type system. When choosing equipment, many specifiers need to get competitive bids or alternate sources of supply. Philips may offer guarantees to address this problem. Heelan comments, "Even now with some lamps that have more than one manufacturer, sole sourcing is a big problem. It's a problem Philips has with the white sodium lamps. It's a big problem GE had when they first put metal halides on the market." And it could be a problem with the other electrodeless lamps entering the market.

Then there's the h-word. "So far it's a lot of hype," says Hillmann of the sulfur lamp. Not that the lighting community is uninterested in new technologies - it's become wary of situations like the 1992 announcement of the E-Lamp. Besides hearing about products and looking at them in installations, specifiers want to examine the product itself and get samples as soon as possible. They want to be satisfied that a product is well developed so that their clients' buildings won't be test sites.

If the announcement of a new and exciting product is distant from its real availability, manufacturers may find themselves in a bind. "It's no longer the latest and greatest when it is finally available. There's no excitement about it," says Fred Davis, president of Fred Davis Corporation, a wholesaler of efficient lighting products. "They [manufacturers] won't get the leading-edge part of the market, and that leading-edge part of the market is a natural lead-in to the larger part of the market." Davis thinks that delays in the North American release of the Genura may be detrimental from a marketing perspective. He says, "Right now there are reflector CFLs in the 20-watt range that are fairly compact. But by the time the Genura comes out, 23- or 25-watt CFLs might be available in a reflector that would be just as compact." Davis thinks the E-Lamp could also fall behind if its release is continually delayed.

Perhaps electrodeless lamps will become popular through government intervention such as the Energy Policy Act. Villere thinks, "We will see...the same thing happen in high-efficiency lighting that we saw in terms of safety and emission control in the automobile industry."

The lighting community remains wary but hopeful about the promises borne by electrodeless lamps. Some imagine installing a lamp and not worrying about it for over 20 years. Some have given up waiting for the E-Lamp and fear there may be a similar wait for the sulfur lamp. Some think the QL has no general applicability and the Genura is not precise enough for architectural applications. But given the right job, electrodeless lamps can be the right tool. The success of electrodeless lamps will depend on the interaction among manufacturers and the rest of the lighting community.