It's the big picture that matters

Why simple choices like switching to fluorescent bulbs make difference.

By Bill Barnes

Lately I have been hearing a lot of rhetoric about why the "green" choice - whether it's light bulbs or cars-may not make sense. The problem is, the numbers that people use tend to be wrong or misleading. Let's look at a few examples.

Question: If we focus on the costs of continually replacing and operating light bulbs in a simple screw-in fixture, which costs more money, incandescent bulbs or compact flourescents?

Answer: Incandescent bulbs, by a long shot. Incandescent bulbs cost three to four times more to operate and they wear out much faster than CF bulbs. As the shelf price of CF bulbs has come down in recent years and the light quality has gone up, the rationale for buying CF bulbs has become incredibly compelling.

Let's back this up with some numbers. Say we replace five 100 watt (w) incandescent bulbs in your dorm with comparable CF bulbs. Further assume that they use about 1/3 of the energy (say 165 watts rather than 500 watts - and note that many CF bulbs use even less than 1/3). That saves you about 335 W for every hour that all five bulbs are on. If they're on for an average of four hours a day (and I know that many bulbs are on longer than this), that's over 1.5 kilowatt-hours (kWh) saved per day.

At about six cents per kWh of electricity, which is about what the University pays, that's over nine cents a day. It may not sound like much, but over a year those savings add up to about 33 dollars. Just for changing five light bulbs.

Yes, the bulbs are more expensive initially. Let's be conservative and give them a high cost ($5 each, which is higher than you will pay if you shop around).

Let's also be conservative and assume that they last only twice as long as the incandescent bulbs. Furthermore, let's just give out the incandescent bulbs for free.

Ok, so, we'll have to wait years for this little example to pay off, right? Wrong. Switching to five CF bulbs will cost $25. But remember what they save over a year, $33. Assuming you use them regularly, we will have the money back in a year.

Note that the bulbs still more than paid for themselves in a year even though I assumed that we only use the CF bulbs four hours a day, made the CF bulbs expensive, made them consume 1/3 of the wattage rather than lower than this, gave the incandescents out for free, and assumed the CF bulb only lasts for twice as long.

If we are more realistic about any of these, putting money into CF bulbs can result in much bigger savings.

As it is, the 25 dollars turned into over 30 dollars by the end of the year and over 60 dollars by the end of two. This is equivalent to well over a 50 percent annual return, with no risk! Find me that kind of return out in the markets!

So why do people still buy incandescent bulbs? Economists are asking this question lately, because "market economics" would predict a much quicker diffusion of CF bulbs.

Economists tend to assume that when there is a dollar in the street, people pick it up. So why are people throwing their money away?

Well, for one thing, as I stated above, the sticker price of the CF bulb on the shelf is still higher than incandescents. This in itself is a huge impediment to a purchase, because consumers often don't think holistically. They see that higher price, and they then turn to that familiar (seemingly cheaper) incandescent bulb. But they forget about the much lower operating costs and the longevity of the CF alternative.

The real world is replete with cases where people don't look at the big picture. People often make their decisions based not on the underlying economics or what is "rational," but on what they hear on the street and what they have done in the past. For example, my wife's parents have been recently saying that she should avoid buying a small car because it isn't "safe." Julie (and this is why I love her) tells them she actually feels safer in a small car. Who is right? What's the number that really matters?

The fatality and injury rate per mile driven for particular cars is a key. And guess what? Many good quality small cars (for example the VW Jetta) have numbers that are comparable or better than their larger counterparts, including SUVs.

As my wife intuitively knows, small cars on average stop much more quickly than big vehicles, maneuver around the problem without rolling over, and generally get in fewer accidents.

In the parlance of auto safety experts, this is higher "active safety." True - when small cars get in an accident they typically are more dangerous (there is less "passive safety"). But if you are truly concerned about safety, then you have to look at the big picture - adding both passive and active safety together.

Hmmmm ... relatively safe small cars that are much cheaper to buy and operate and that are better on the environment ...

And what's that you say about the mercury associated with CF bulbs? Well, even if we grant that they are nastier as a product, they are not nastier if you look at the whole picture.

Why? Because mercury is also emitted straight into the air by the utility companies powering your lights. And CFs use a lot less energy .. hence less mercury in use .. not to mention carbon dioxide.

So ... here's a plea from a hard-headed "business" perspective. When we make decisions, at home and in organizations, let's keep the (big picture) numbers in mind.