Wednesday, December 26, 2007

Let There Be (Efficient) Light

Like many of us, the U. S. Congress often puts off things till the last minute. Last week, just before breaking for the Christmas recess, our elected representatives passed an energy bill. Unlike earlier toothless bills, this one will grow some teeth if we wait long enough and don't let another Congress pull them first. Besides an increase in the CAFE auto-mileage standards, the bill will make it illegal by 2012 to sell light bulbs that don't meet a certain efficiency standard. And most of today's incandescents can't meet the mark.

Now what has this got to do with engineering ethics? You could argue that there's no ethical dilemmas or problems here. You could say it's legal, and therefore ethical, to design, make, and sell cheap, inefficient light bulbs right up to the last day before the 2012 deadline, and thereafter it will be illegal, and then unethical, to do so. No ambiguities, no moral dilemmas, cut and dried, end of story. But simply stating the problem in that way shows how there has to be more thought put into it than that.

For example, systems of production and distribution don't typically turn on a dime. One reason the legislators put off the deadline five years into the future is to give manufacturers and their engineers plenty of time to plan for it. And planning, as anyone who has done even simple engineering knows, is not always a straightforward process. To the extent that research into new technologies will be required, planning can be highly unpredictable, and engineers will have to exercise considerable judgment in order to get from here to there in time with a product that works and won't cost too much to sell. That kind of thing is the bread and butter of engineering, but in this case it's accelerated and directed by a legal mandate. And I haven't even touched the issue of whether such mandates are a good thing, even if they encourage companies to make energy-efficient products.

In the New York Times article that highlighted this law, a spokesman for General Electric (whose origins can be traced directly back to incandescent light-bulb inventor Thomas Edison) was quoted as claiming that his company is working on an incandescent bulb that will meet the new standards. Maybe so. There are fundamental physical limitations of that technology which will make it hard for any kind of incandescent to compete with the compact fluorescent units, let alone advanced light-emitting diode (LED) light sources that may be developed shortly. But fortunately, Congress didn't tell companies how to meet the standard—it just set the standard and is letting the free market and its engineers figure out how to get there.

I have not seen the details of the new law, but I assume there are exemptions for situations where incandescents will still be needed. For example, in the theater and movie industries, there is a huge investment in lighting equipment that uses incandescents which would be difficult or impossible to adapt to fluorescent units for technical reasons. It turns out that the sun emits light that is very close to what certain kinds of incandescent bulbs emit, and for accurate color rendition the broad spectrum of an incandescent light is needed. And I have a feeling—just a feeling—that, like candles, incandescent light bulbs will be preserved in special cultural settings: displays of antique lighting and period stage sets, perhaps. Surely there will be a way to deal with that without resorting to the light-bulb equivalent of a black market.

But most of these problems are technical challenges that can be solved by technical solutions. One of the biggest concerns I have is an esthetic one: the relative coldness of fluorescent or LED light compared to incandescent light. This is a matter of the spectral balance of intensity in different wavelengths. For reasons having to do with phosphor efficiencies and the difficulty of making red phosphors, it's still hard to find a fluorescent light that has the warm reddish-yellow glow of a plain old-fashioned light bulb, which in turn recalls the even dimmer and yellower gleam of the kerosene lantern or candle. Manufacturers may solve this problem if there seems to be enough of a demand for a warm-toned light source, but most people probably don't care. For all the importance light has to our lives, we Americans are surprisingly uncritical and accepting of a wide range of light quality, from the harsh glare of mercury and sodium lamps to the inefficient but friendly glow of the cheap 60-watt bulb. I'm not particularly looking forward to getting rid of the incandescent bulbs in my office that I installed specially as a kind of protest against the harsh fluorescent glare of the standard-issue tubes in the ceiling. But when it gets to the point when I have to do it, I hope I can buy some fluorescent replacements that mimic that warm-toned glow, even if I know the technology isn't the same.

Sources: The New York Times article describing the light-bulb portion of the energy bill and its consequences can be found at A February 2007 news item describing General Electric's announcement of high-efficiency incandescent lamp technology (though not giving any technical details) is at

1 comment:

  1. Induction lighting is one of lifes great mysterys, why doesnt anyone know about them. When the lighting application requires the performace of HID or metal halide bulbs only induction lighting can measure up. LEDs are great in low light scenarios but in applications like street lighting they just will not do and unlike CFL bulbs the mercury in Miser induction lights is solid.
    The bulbs can be bought at