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Understanding flourescent light bulbs

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  • Professor: Considering soil, water must join air preservation efforts
  • Temperature of flourescent light bulbs affects its lifespan, professor says
  • Improvements must be made in disposal of flourescent light bulbs

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Rachel Oliver
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HONG KONG, China (CNN) -- Save energy -- two words that have rapidly become a modern day mantra. But some are now asking, at what cost?

A Hong Kong electrical engineering professor says a short lifespan hurts the compact flourescent light bulb.

One person asking that question is City University of Hong Kong's professor Ron Hui, chairman of the electronic engineering department, and co-author of a recent paper published in a peer-reviewed journal on the environmental impact of fluorescent lighting.

Hui has a problem with compact fluorescent light bulbs (CFLs), specifically electronic ones. He wants them out of people's homes as much as an increasing number of governments around the world want incandescent light bulbs out of our homes. Hui wants them replaced by magnetic CFLs instead. Why? CNN spoke recently with Professor Hui.

CNN: What is the problem with CFLs?

Professor Ron Hui: We support the idea of energy-efficient lamps but we have to tell the public about the consequences. The lifetime of electronic CFLs (eCFLs) is very limited; on average nine months and no more than one year. Many have the misconception that energy saving equals being friendly to the environment. But to be environmentally friendly two factors must go hand in hand. First, we must not pollute the atmosphere; and second we must not pollute the soil and the water. EFLs do save energy, but if the lifetime is, say, 10,000 hours, that's 1.1 years. And every year we throw these products in the garbage bin, so that's hundreds of millions a year.

CNN: Most have the impression CFLs last a long time. But are you saying this is not the case?

Hui: The [eCFL] manufacturer will quote 7,000 to 10,000 hours of usage, but the actual operating time is based on the temperature. [eCFL's] component, the electrolytic capacitor, is highly temperature sensitive and at the moment, the best one has a lifespan of 10,000 hours at a temperature of 105 degrees Celsius (221 degrees Fahrenheit). But in practice, the temperature will be a lot higher and it could go above 130 degrees Celsius. Every 10 degree increase in operating temperature means the lifetime drops by 50 percent. Very often when eCFLs fail, it is the electrolytic capacitor that has failed. The failure rate is high, typically six to nine months, particularly in some regions.

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CNN: What is the main problem with how we dispose of these CFLs?

Hui: The problem is, when you open an eCFL, you will see an electronic circuit. On the printed circuit board we have a layer of anti-flame resistant coating made of PBDE -- this is highly toxic and in each lamp we have 3-5 milligrams of mercury. The safe intake of mercury for a human body is a few micrograms. One milligram is 1,000 micrograms. The problem is that eCFL is an integrated product. ... So the whole of it gets thrown away. And for the eCFL, you can't recycle it as you cannot reuse the used circuit board. And if you do recycle the tube, what about the e-waste? No one wants to talk about it.

CNN: Some say that in the absence of recycling schemes landfills remain an option. Are you saying that is not the case?

Hui: Government departments like the U.S. Environmental Protection Agency have misleading arguments, like landfills are OK. In many countries, like Hong Kong, the garbage truck will compress the garbage [en route to the landfill]. The lamps will be broken which means the mercury will be transferred all over the city. The Hong Kong government told us that the landfill can handle mercury. I told them the mercury vapor will escape before it gets there. Even if they can safely transport the CFLs [to the landfill], the safety layer has a lifespan of about 100 years. So you are building a time bomb for future generations.

CNN: But don't CFLs cut down on the overall amount of mercury produced compared to incandescent light bulbs?

Hui: Talking about the amount of mercury emitted from power stations is a false argument. With power stations, the contamination is in that area, but now we are talking about bringing that contamination into every home, every street. We may have less mercury in the whole production process than with incandescent light bulbs but the difference with CFLs is that the mercury will be in our homes and in our streets.

CNN: So if we can't use CFLs, what can we use?

Hui: We do have alternatives: a magnetic CFL (mCFL). Inside is iron core and copper wiring, that's all, no electronics. One company that makes these offers a lifetime guarantee of 17 years and at the end of that 17 years you can recycle the iron and copper so it is a recyclable technology. One Austrian company manufactures both and says their magnetic CFLs will last 30 years and after that you can still recycle it. In a dimmable system we have proved that magnetic ballasts are as energy-efficient as electronic ballasts. We believe magnetic ballasts are the most sustainable solution as we don't have the e-waste problem.

CNN: But you still have the problem with the mercury, don't you?

Hui: If you dropped both lamps, the mercury would be the same and it would still be harmful. Magnetic CFLs do have mercury too, but the lamp is detachable. So you can recycle the tube, and you can keep the magnetic ballast. Magnetic CFLs allow the tube to function through its lifetime; with eCFLs the electrolytic capacitor always fails first. The best solution is magnetic CFLs and to have a set up to recycle the tubes. I see no reason to generate hundreds of millions of tons of e-waste. After all, they dump it in China, India and Africa. Most of the e-waste collected in Europe [for recycling] ends up there. Before you build a nuclear station, you think about how to dispose of the waste. If we have no good reason to create all this e-waste then we should stop it.

CNN: How difficult is it to recycle the tubes?

Hui: We do have the technology to recycle the mercury, and the lamp manufacturers must pay for the recycling as they make the profit.


CNN: So what is needed here, government intervention?

Hui: eCFLs is a highly profitable business so it will be difficult for companies to pursue more environmentally-friendly products. Industry standards are heavily influenced by the companies as the members of the companies themselves are the ones drafting the standards. Hopefully when the public know more about this, then hopefully governments will [step in].We should educate the public with genuine information and then they can choose.

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