Light bulbs as we know them will soon become a thing of the past. In less than 8 months, incandescent light bulbs – the ones folks have been using since Edison discovered how to make one work – will be phased out. They will be replaced with equivalent LED (light emitting diode) or OLED light bulbs (organic light emitting diode).

As of January 2012, 100 watt light bulbs will become illegal to manufacture or distribute. The law is part of a mandate instituted by Congress in 2007 in an effort to encourage energy efficiency. By 2014, all incandescent light bulbs with 40 watts or more will become outlawed.

The problem with incandescent light bulbs is that they waste much of their energy producing heat. The 100 watt light bulb, for instance, produces so much heat that Hasbro’s Easy Bake Oven uses it to cook food. The idea is to produce the same brightness without wasting the energy to produce heat.

The challenge today is to make an LED bulb, an OLED, or a compact fluorescent bulb that will fit the traditional sockets now used by incandescent bulbs. The problem with fluorescent bulbs is that they emit a toxic mercury vapor when they break and brighter models don’t fit in standard fixtures. LED bulbs produce a small amount of heat but are expensive, and the heat they produce shortens the life of the microchips used to run them. OLEDs are glowing sheets that use special chemicals that spoil when introduced to oxygen.

At Philadelphia’s LightFair, several companies will be introducing new LED bulbs, some with the equivalent brightness of a 100 watt bulb. To be sure, though, these replacements will be expensive compared with the traditional incandescent bulb. While the government’s goal is to have 60 watt bulbs cost no more than about $10 by 2015, the current cost of LED bulbs are steady at around $40 to $50 each.

According to Bob Karlicek, the director of Smart Lighting Research Center in New York, a new approach to lighting is needed. In order to use LED most effectively, new fixtures and lamps are needed to spread out the LEDs and avoid the heating problem. Only then will LEDs become a viable, affordable substitute for the incandescent bulb.