With the world gradually turning its back on inefficient (incandescent) lighting, what should you use as a green replacement? The phasing out of incandescent light bulbs began several years ago with much of Europe banning incandescent bulbs in 2009.1 In the United States, incandescent light bulbs will begin to disappear in 2012, with nearly all banned by 2014.2 The U.S. ban does not specifically target incandescent light bulbs, but it does target inefficient bulbs. The ban will affect an estimated 4 billion U.S. light sockets, and once they contain energy-efficient alternatives, “household utility bills will be slashed by more than $18 billion a year, while the atmosphere will be spared 100 million tons of power plant carbon dioxide emissions.”3 Unfortunately for incandescent bulbs, no improvements in their energy efficiency are likely, leaving the market open for new forms of residential lighting. So let’s discuss lighting options on the market, focusing on: compact fluorescent lights (CFLs), halogen lights, light-emitting diodes (LEDs), and electron stimulated luminescence (ESL).
Compact Fluorescent Light (CFL)
CFLs have received hype in recent years for their energy efficiency. Because they are a cheap and readily available alternative, most environmentally conscious consumers recognize them as the go-to green light bulb. A CFL bulb costs around $4 and is 75% more efficient than the old incandescent bulbs.5 They also last around 8 times longer than incandescent bulbs—10,000 hours versus 1,000 hours—meaning you will not need to buy them as frequently.6 CFL shortcomings include their narrow spectrum of light, producing what many call a “cooler” light, they cannot be dimmed, and they contain toxic mercury.7 The mercury is of further concern because it is vapor, and therefore far more easily ingested than liquid mercury (assuming you are not eating an animal such as fish that consumed mercury).8 Vapor mercury is very dangerous and should be treated with great caution during CFL cleanup and disposal. Further concern for the environment emerges when one considers where most CFL bulbs end up. California law mandates proper recycling of CFLs, however, only 20 percent or less of CFLs are being recycled.9 This means California dumps millions of CFLs into landfills where their mercury can potentially enter the groundwater supply, endangering humans and the environment.10 CFLs are cheap and efficient, but they are not the best long-term investment and may be doing a great deal of environmental damage.
Halogen Lights
Halogen lights render “sharp” light, are relatively cheap, turn on without any delay (unlike many CFLs), and do not contain toxic mercury.12 However, they may not be much of an improvement over incandescent bulbs when considering energy efficiently. Lumens—a measure of the power of light perceived by the human eye—divided by watts gives consumers a sense for the energy efficiency of their light bulb.13 Incandescent bulbs produce 10 lumens per watt, while halogens produce 15 lumens per watt.14 When compared to CFLs’ 50-60 lumens per watt, halogen bulbs show hardly any improvement over incandescent bulbs. Finally, halogen lights only live about as long as incandescent bulbs, which is not very long, and get extremely hot—creating a fire and safety hazard.15 When looking at the big picture, halogens may be sharp, but they are not sustainable. I cannot recommend halogens as a viable green lighting option.
Light-emitting diode (LED)
LEDs are commonly cited as the future of lighting due to their high efficiency, durable nature, and lack of mercury.17 The federal government, through the Department of Energy, has even invested $37 million in grants funding research and development for LED technology.18 LEDs have a significantly higher level of energy efficiency than incandescent, CFL, and halogen bulbs. LEDs range from 60 to 135 lumens per watt.19 They can also be extremely small, durable, produce a great range of colors, and last way longer than anything else on the market (35-50,000 hours).20LEDs present many clear advantages over CFLs, but a few technicalities may prevent people from fully embracing LEDs in their homes.
Since most white LED light comes from the mixture of red, blue, and green lights, it produces a different spectrum than the sun. As a result, LEDs often make objects appear more blue or green than natural, and red objects are particularly altered from how they “naturally” appear under the sun.21 However, technology is always improving, and we may see more “natural” looking LEDs in the near future. Another interesting disadvantage of LEDs is their inability to cope with heat. They may be incredibly efficient and long-lasting in ideal conditions, but when exposed to hotter environments, the efficiency drops and the life-span plummets.22 To combat this heat accumulation issue, many LEDs have heat dissipation requirements which involve heat sinks or fans surrounding the bulb to keep it cool.23 All that aside, you are probably most concerned with the price, and therein lies the big problem with LEDs. Their initial cost is usually rather high—ranging from $40-$100 for a bulb. If you can average that cost over the life of the bulb and factor in how much energy you are saving, then they are definitely worth it, but spending that much money for one light bulb intimidates many people.
Electron Stimulated Luminescence (ESL)
A new company known as Vu1 (pronounced “view one”) has come up with an entirely new energy efficient lighting technology that uses “accelerated electrons to stimulate phosphor to create light,” a process similar to old television screen luminescence.25 They claim their lights are very energy efficient, provide superior quality, are fully dimmable, and contain no toxins.26 Their R30 (reflector flood light bulb) has a life of 11,000 hours, is 75% more efficient than an incandescent bulb, and currently sells for $20, making it more affordable than similar LEDs on the market.27 It produces around 30 lumens per watt (less than CFLs or LEDs, but substantially better than incandescent bulbs) and has a lifespan comparable to most CFLs. The biggest downside to this technology, other than the price tag, is the fact that it is brand new. General Electric or Philips does not produce these bulbs, rather, a startup company that is struggling to get their bulbs to market makes them. Vu1 claims that a standard “Edison type” or “A-type” bulb will be on the market later in 2011, however, the future of any startup company is always uncertain.28 Right now, these bulbs are not yet available for purchase, but when they do become available I would recommend trying one out!29
The Future of Sustainable Lighting
It is extremely difficult to find a perfect replacement for incandescent light bulbs. Lights like halogen may offer a sharp alternative, but they are hardly better when considering efficiency and the environment. CFLs and LEDs clearly dominate the market in efficiency, but they each have their own drawbacks, whether it be inferior lighting quality, toxic mercury, or an unreasonable price tag. ESL presents an intriguing balance between efficiency and light quality, but their future is difficult to predict without a product yet available for consumers on the market. The lighting industry is rapidly changing, so stay vigilant, and always consider the tradeoffs of every brand, and make sure to dispose of your bulbs properly!
Vocabulary to consider when buying a bulb:
