Quote:
Originally Posted by HarryT
To the consumer, it doesn't. That's why, I think, the EU's method of doing it - by passing legislation to ban the sale of incandscent lightbulbs - is, I think, the only way that you're going to make people change.
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Quote:
Originally Posted by Steve Jordan
@Xenphon: So leave my 1 bulb because it does so little damage? I submit that if it was the only bulb out there, fine. But in fact, it has millions of friends, and the damage is cumulative... As I said, everyone has an excuse to slack off somewhere. Problem is, we all end up slacking off... and look where we are...
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Actually, I was attempting what I thought would be a straight-forward economic argument. Remember the following useful and well proven concepts: time-value of money, time required to pay back investment, value of energy/pollution saved given when the savings happens.
With those concepts in mind, here's the questions that lead to the economic argument:
- Given the current usage of that specific light-bulb, what is the time needed to pay back investing in a more expensive bulb?
- What fraction of my total electric usage is represented by the attic bulb, and what fraction is represented by the other lights where I might place a CFL instead?
- If I spend $5 on a CFL for my attic, does that reduce my ability to spend $5 on a CFL that would go in a more heavily used fixture?
Oh yeah, a further piece of data about that bulb -- it's an old-fashioned bulb of a size and shape I haven't seen in any store in my memory (which suggests that it was installed before the mid-60s). It appears to be roughly a 100W bulb, but it's difficult to tell, because it isn't marked (I just looked last night!).
If I estimate the life of such a bulb at 1000 hours usage (arbitrary, probably too high, but typical of the bulbs I might buy to replace it now), we see that it will consume 100KWh over its entire service life. That's about $10 worth of electricity (in back-of-the-envelope numbers). Now, even though I estimate that it is likely to be
more than 40 years old, let's use the 20 years I've lived in the house as a baseline (that is, we're assuming it burns out this evening after a total lifespan of 20 years). We'll also assume that the use of electricity (and the price of electricity!) is evenly spread across the entire period -- 50 cents of electricity each year.
Note that this set of assumptions boils down to using the attic light for 50 hours per year; in reality I probably haven't used it as much as 50 hours over the entire 20 years we've been in the house! But never mind, we'll run with it.
More facts: a comparable CFL costs $5 at my local big-box store (actually a bit less, but we're using round numbers to make the calculations easy), and consumes 28W for the same light output. We'll call that 25W for simplicity. A new 100W incandescent costs $1 (actually rather less, but... round numbers!)
First we'll calculate the payback period for a CFL in the attic (Q1 above):
So if I install a CFL in the attic I spend $5 today, and gain back $0.375 each year into the future. If I install another 100W incandescent, I spend $1 today and gain back nothing each year. Without considering the time value of money, the payback period for putting a CFL in my attic is...
Ten years eight months.
Normal financial estimation says that (low-risk) investment paybacks under 3 years are "no-brainers." Jump on the opportunity right away.
Paybacks under 7 or 8 years are worth investigating; paybacks over 8 years are questionable. Remember, this is BotE estimation for simple stuff, not questions of "corporate strategy" or long-term R&D.
Simple stuff, like light-bulbs and insulation, and vehicle purchases.
If we estimate the time value of money using a 3% deflator, we would say that this years savings is worth $0.375 today, next year's saving is worth $0.36, and the final (10th) year's savings is worth $0.28. This adds another couple of years to the payback period.
BotE says not to put a CFL in the attic... at this time!
Now let's look at Q2: Is there some other bulb in the house I might replace with a CFL instead of the attic bulb?
Answer:
Sure. I have some closets whose lights are used substantially more than the attic light. I probably replace their bulbs every 3rd or 4th year. Assuming, once again, 1000-hour 100W bulbs (for simplicity) and the same costs as above, I'm looking at $10 in electricity spread over 3 or 4 years. Using 4 years as the number, BotE says that payback period is right around 2 years. Time to replace those bulbs, even if they haven't burned out yet!
(Good thing I already did...)
Now for Q3:
Even assuming it costs $0.50 per year, that attic bulb is insignificant in my total electricity usage picture. If I want to invest $5 ($4, really due to the up-front price-difference in bulb cost) in reduced usage, I should put the money where it will make a larger difference. Specifically, that attic bulb is certainly the very last one that I should consider replacing. Every other light in the house sees substantially more use.
Before spending extra money replacing that particular bulb, I should first spend money on:
- High-efficiency bulbs everywhere else in the house.
- Making sure that wall-wart transformers that are plugged in to the wall are energized only when the device they power is active, and not at any other time.
- A more efficient refrigerator!
- A more efficient fan on my furnace.
- A more efficient air-conditioner (if I use one at all, which I mostly don't).
- A very very long list of other items that matter more.
In fact, the list of items that matter more than the attic light is
so long that I cannot afford to do them all in any one year. Thus, any extra money I spend on the attic light
really does reduce my ability to deploy that money on
solving a more important problem with greater impact on energy usage and the environment. Really!
So, what I believe I have shown above is that efficient lights aren't the right solution for rarely used fixtures, unless and until all the higher-benefit/shorter-pay-back problems are addressed first.
To connect back to the original discussion:
Don't legislate lower efficiency things out of existence! Instead, educate people about the choices they are making. You'd be surprised what response you get when you point out that folks are unthinkingly leaving money on the table (or worse, sending it to "the big bad utility company!") when they could have used it for something they wanted more but couldn't afford.
I submit that Steve's propose Onuissance is better served through education than legislation in cases like this.
Xenophon