Induction lamps - from Energy Star.Gov, Building Lighting Chapter

Induction lamps, also called electrodeless lamps, consist of a high-frequency power generator, a coupling device that generates a magnetic field (essentially an antenna), and a glass housing that contains the gases and phosphor coating—no electrodes required. The main advantages of induction lighting are the ability to produce a substantial amount of light in a relatively compact package and a long lamp life due to the elimination of the electrodes. The major drawback of induction lighting is high installed cost. In applications where maintenance costs are high, though, induction lighting systems can be cost-effective.

Existing induction-lamp products are aimed at two distinct market niches. The higher-wattage versions available (55 to 165 W) offer very long life (up to 100,000 hours) and can be a good choice anywhere that relamping and maintenance are difficult or hazardous. These lamps have been used in all of the following locations:

Escalator wells
High-ceilinged spaces, including atriums (such as over open mall areas) and in warehouses and factories
Parking garages
Roadways, including bridges, tunnels, underpasses, and signs
Exterior pedestrian lighting

Lower-wattage induction lamps (20 and 23 watts) are also available as direct replacements for medium-base incandescent and compact fluorescent lamps. They offer efficacies of about 50 lumens per watt, CRIs of 82, and an expected life of 15,000 hours.