Reinventing the Light Bulb « Forbes ENG102 Weblog

 Reinventing the Light Bulb

October 14, 2008

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In response to the American oil crisis in 1973, an engineer with General Electric named Ed Hammer, invented the modern compact florescent bulb. While the bulb more than met with General Electric’s design goals, it was not practical for fabrication at that time. New factories would need to be built to make the new bulbs costing GE a whopping $25 million dollars to build. Shortly thereafter, GE shelved the idea. Unfortunately, for GE, the design leaked out and before long the CFLs began hitting the shelves followed by all their hype. . The light bulb as we knew it had been reinvented. Nevertheless, how does this new technology compare to our old technology as far as lifespan, light output, electricity usage, cost, safety, availability, and disposal. (Kanellos)

The average rated life span of a CFL is 8 to 15 times that of an incandescent. So what does that mean to you and me? An incandescent bulb has a rated lifespan of 750 to 1,000 hours. A CFL typically will last between 6,000 and 15,000 hours; five year lifespan. However, the lifetime of any bulb depends on many factors: operating voltage, manufacturing defects, exposure to voltage spikes, mechanical shock, and frequency of cycling on and off. (Masamitsu)

The life of a is cut 85% if it is only turned on for five minutes at a time, reducing its lifespan to the level of an incandescent lamp. The US Energy Star program recommends leaving a CFL’s on at least 15 minutes at a time. (Energy Star Program)

As CFLs age they produce less light, depreciating exponentially. The fastest loss being soon after the lamp is first used. By the end of a CFLs lifespan, you can expect that it will only be producing 70-80% of its original light output.

CFLs use between one fifth and one third of the power of equivalent incandescent bulb. In 2001, lighting accounted for 9% of the United States household usage. Therefore, in widespread use, CFLs could save as much as 7% of total US household usage. If incandescent lamps were replaced by CFLs within homes, the heat produced by the building’s lighting system will be reduced. At times when the building requires both heating and lighting, the building’s central heating system will then supply the heat. If the building requires both illumination and cooling, then CFLs will use less electricity themselves and will reduce the load on the cooling system compared to incandescent lamps. Therefore, your electrical savings would be two-fold. (Masamitsu)

While the purchase price of an integrated CFL is 3 to 10 times greater than that of an equivalent incandescent lamp, the extended lifetime and lower energy use will compensate for the higher initial cost. The manufactures of CFLs suggested, theoretically, one could look at his utility bill and imagine a 12% discount to estimate the savings of CFLs over the incandescent bulbs currently in use. Even in commercial settings, CFL are extremely cost effective. While CFLs require more energy in manufacturing than incandescent lamps, this is said to be offset by the fact that they last longer and use less energy than equivalent incandescent lamps during their lifespan.

CFLs, like all fluorescent lamps, contain small amounts of mercury as vapor inside the glass tubing and it is a concern for landfills. The mercury from CFLs is released and contributes to air and water pollution. Members of the National Electrical Manufacturers Association (NEMA) have voluntarily agreed to cap the amount of mercury used in CFLs. Some manufactures have bulbs available with very low emissions. In 2007, Traplight claimed its new Genesis Fusion line contained only 1mg of mercury, making it the lowest EnergyStar approved bulb in North America. (Energy Star Program)

Widespread use of CFLs has been slowed for fear of the amounts of mercury however; the amount of mercury released by a broken CFL bulb greatly exceeds EPA safety standards. Spent lamps should be recycled to contain the small amount of mercury in each lamp. Today it is believed that about 3 percent of CFL bulbs are properly disposed of or recycled. Safe disposal requires storing the bulbs unbroken until they can be processed. Home Depot is the first American retailer to make CFL recycling options available. The U.S. Environmental Protection Agency recommends that, in the absence of local guideline, fluorescent bulbs be double-bagged in plastic bags before disposal.

Some governments are considering stronger measures to entirely displace the current incandescent lamps. These measures include taxation, or bans on production of incandescent light bulbs. Australia and Canada have already announced nationwide bans on incandescent bulbs.

In the United States and Canada, the Energy Star program labels compact fluorescent lamps that meet a set of standards for starting time, life expectancy, color, and consistency of performance. The intent of the program is to reduce consumer concerns due to variable quality of products. Those CFLs with a recent Energy Star certification start in less than one second and do not flicker. There is ongoing work in improving the ‘quality’ of their light. (Energy Star Program)

Reinventing the Light Bulb « Forbes ENG102 Weblog