Ethiopian Review

Thomas Edison exhibits a replica of his first successful incandescent lamp, which gave 16 candlepower of illumination. Today, there is a 50,000-watt, 150,000-candlepower lamp

Across Europe, it’s just about lights out for the humble incandescent bulb. The European Union began phasing out incandescents on Sept. 1, banning stores from buying new stock.

It’s all part of an effort to drive consumers toward a better bulb: compact fluorescent lamps (CFLs), which last 10 times longer while consuming less than a third of the electricity as incandescents. At up to $10 each, CFLs are more expensive, but experts say they pay for themselves in energy savings in just a few months. The E.U. is even touting the switch as an economic stimulus; experts estimate that the swap to CFL will save customers €5 billion annually. Bucks for bulbs, anyone?

Though Thomas Edison is usually cited as the father of the lightbulb, it’s more accurate to give Edison credit as the creator of the first commercially viable lightbulb. As early as 1820, inventors were honing in on the principles that would lead to the first electric illumination. An English inventor, Joseph Swan, took their early work and developed the basis of the modern electric lightbulb in 1879 — a thin paper or metal filament surrounded by a glass-enclosed vacuum. When electricity runs through the filament, the bulb glows. Edison refined the design, trying filaments made out of platinum and cotton before eventually settling on carbonized bamboo, capable of burning for more than 1,200 hours. With Edison’s design — and the settlement of a lawsuit with Swan that resulted in the two inventors’ joining forces in 1883 — electric lighting became viable for the first time.

The development of the lightbulb sparked the spread of electric power in the U.S. Edison was behind the creation of the first commercial power plant in 1882, and New York City had electricity by 1892. By the late 1930s, the Rural Electrification Administration, one of President Franklin D. Roosevelt’s New Deal programs, had brought electric lighting to nearly every corner of the country. Development didn’t stop on the bulb, either: researchers have honed Edison and Swan’s design further, refining the filament by using tungsten metal and filling the vacuum with gas, both of which increase the life span of a bulb. Still, even modern bulbs are inefficient — less than 6% of the energy used by a bulb goes into producing light. The rest is given off as heat.

CFLs are designed to address this inefficiency. The technology for the bulbs was developed as early as the 1890s as lights, but General Electric perfected the design during the U.S. energy crisis in the 1970s. CFLs use electricity to excite mercury vapor, which produces ultraviolet light that is filtered through a coating on the bulb to become visible light. GE shelved the design, as the bulbs would have required new manufacturing plants, but the specs leaked over the years. Though assembling a CFL is still costly, the bulbs are environmentally friendly and save consumers money in the long run, forming the basis of the E.U.-mandated switch.

But this mass changing of the bulbs isn’t universally appreciated. CFLs emit light in a different spectrum than their incandescent counterparts, producing a light that’s “cooler” — tinged a light blue or green — than the yellowish hue of an incandescent. Many people complain that the effect is less aesthetically pleasing. CFLs also have environmental issues because of the danger of mercury exposure if the bulbs should break — making disposal tricky. And some people allege that constant exposure to fluorescent light causes health problems, though experts are largely skeptical of the claim.

These concerns, however, take a backseat to those over lightbulbs’ environmental impact — replacing a single incandescent bulb with a CFL in every U.S. household would be the environmental equivalent of taking 7.5 million cars off the road. The U.S. plans to follow Europe’s lead and outlaw incandescents in 2012. Still, at least one light will stay on: the Centennial Light in Livermore, Calif., has been shining continuously in the same firehouse since 1901, making it the longest-burning bulb on the planet.

(By Dan Fletcher | TIME.com)