The Big Picture

It’s amazing to me that  the big picture often gets overlooked. I am not talking about willful distortion, but about well-intentioned people looking at only one part of the equation in an attempt to arrive at a good but simple solution. Here are two examples, both concerned with reducing pollution.

All over the world, incandescent light bulbs are being phased out in favor of compact fluorescent lamps, which use less energy to emit the same amount of light. Incandescent bulb filaments create light by glowing white-hot, so a lot of electricity is converted into the wasteful byproduct of heat.

Compact fluorescent light bulbs have their own disadvantages: They contain mercury and are toxic, creating a disposal problem. (Don’t throw them in the trash!) They emit a colder, bluish light, which can contribute to the “winter blues” (now called “seasonal affective disorder”). However, the consensus is that to save the Earth, these negatives are worth it.

One question few people have asked is: “Where does the “wasted” energy of an incandescent bulb go?” The answer is simple. It heats the room.

I live in Seattle, where we turn on the lights mostly in winter, when it is cold. When it is cold, we also run the heater. Switching to compact fluorescent light bulbs will decrease my electricity consumption, but it will increase the gas used by my heating system. The net result will be zero energy savings.

For northern regions, the phase-out of incandescent bulbs looked only at one part of the equation, but not the big picture. Of course, if I still lived in Texas, and if I lived in an air-conditioned house rather than one with ceiling fans and cross-ventilation, then the switch to compact fluorescent bulbs would save energy twice: Once with the reduced consumption of the light bulb, and again with the reduced energy use of the air conditioning system. Also, the “winter blues” aren’t so much of a problem in Texas. So it would make sense to phase out incandescent light bulbs in Texas, but keep them in Seattle.

Cars are another issue that requires a nuanced view. Many people recommend replacing older cars with newer ones that get better gas mileage to reduce emissions. Such generalizations overlook the emissions and environmental impact of making the new car. Producing raw materials and manufacturing at car factories cause a lot of pollution. Car parts and finished cars are shipped all over the world, which uses a lot of energy. Generally, it is recognized that 10-15% of a car’s pollution is caused by its manufacture, the rest by driving it. (There also is the environmental impact of disposing of the old car.)

My family’s car is 19 years old, and gets about 25 mpg. That isn’t great: I could buy a Honda Fit that gets 33 mpg – a huge improvement of almost 30%. Wouldn’t that be great for the environment?

The surprising answer is “No.” Our car is driven about 4000 miles a year. That means that the Honda Fit would reduce our family’s annual gasoline consumption from 160 gallons to 121 gallons, a savings of 39 gallons. If the pollution of making the car is equivalent to about 600 gallons of gas (200,000 miles lifespan : 33 mpg x 10%), then the Honda Fit would take over 15 years to “amortize” the pollution caused by its manufacture – if it lasts that long.

Of course, if you drive 40,000 miles a year, then your Honda Fit would amortize its manufacture in less than 2  years, and both the environment and – somewhat later – your budget would come out ahead.

These examples show that simple “one size fits all” solutions tend to overlook crucial nuances. Compact fluorescent light bulbs make a lot of sense in hot climates, but not in Seattle. Replacing an old car with a new, more fuel efficient one makes sense for people who drive a lot, but not for many cyclists who use their bikes as their main transportation.

Similar questions occur in cycling. For example, are wider tires faster? Once again, the answer is: “It depends.” On a smooth indoor track at very high speeds (above), relatively narrow tires at high pressures may be most efficient.

For a long-distance ride at lower speeds (where aerodynamic drag is less important), on rougher roads (where suspension losses can be very large), much wider tires at much lower pressures undoubtedly roll faster.

Simple answers tend to overlook crucial factors. You really have to look at the big picture to make good decisions for your situation.

About Jan Heine, Editor, Bicycle Quarterly

I love cycling and bicycles, especially those that take us off the beaten path. I edit Bicycle Quarterly magazine, and occasionally write for other publications. One of our companies, Bicycle Quarterly Press publishes cycling books, while Compass Bicycles Ltd. makes and distributes high-quality bicycle components for real-world riders.
This entry was posted in Testing and Tech, Uncategorized. Bookmark the permalink.

45 Responses to The Big Picture

  1. Andy says:

    In the case of choosing a higher fuel economy car, I can’t see how the initial energy inputs matters unless when you buy a new car you put the old one in the dumpster or leave it in the woods to rust. The assumption should be that any driveable car will still be used until eventually it has enough broken parts that it is no longer driveable. Buying a new one doesn’t mean the old one instantly stops existing though, so that shouldn’t necessarily be factored into the calculation.

    • If more people buy new cars, then there is less demand for old cars, and they do end up in the junkyard. It seems ridiculous to me that if the clutch needed replacing on our car, it would cost almost as much to fix as the car is worth… Compare that to 20-year-old constructeur bikes. Even my old Singer, with its 120,000+ miles, is worth more than my car. The car is half as old and has fewer miles! When new, the car cost 2-3 times as much as the Singer… So yes, buying new cars drives down the value of old ones and makes them less “cost-effective” to maintain and repair.

    • AC says:

      Remember “Cash for clunkers”? They did exactly that: They took cars that were roadworthy, many of them in very good shape, and marked them for destruction. A total farce.

  2. Andy says:

    I’ve read a lot about tire sizes and come to the conclusion that (at least for me) the width has little importance to speed/effort except on rough gravel roads, but weight and thickness are much more important generally. I sometimes encounter dirt roads on rides when I’m exploring, and do fine on dirt or small gravel on 23mm tires at ~90psi and can still keep up a good speed with little perceived extra effort. When I seek out dirt roads, I use 28mm tires at ~70psi since they don’t “jump” off the side of larger pieces of gravel. There have only been a few roads I came to that seemed to warrant anything wider, but I aim for what seems best for the majority of the ride.

    I have found that lighter weight tires of the same width do feel much better though. I’ve mostly used thick “city” tires for commuting, and changed to much lighter Paselas (saved ~400g for the pair). I get so few flats that it’s not worth worrying about – I recently found that I had the original tube on a front wheel, which has over 9000 miles on it now without any patches.

  3. Solomon Gursky says:

    While I appreciate and undestand your overall argument, your light bulb analogy is not quite accurate, because a lightbulb is a highly inefficient way to heat a room. If you have even a moderately efficient heating system, switching from incandescent to compact flourescent bulbs will give you a net energy savings–even in Seattle.

    • Actually, the light bulb is 100% efficient in converting electricity to heat. What else does it produce?

      • Todd S. says:

        This is a valid point. Last year, I helped my daughter with her science project which was measuring the radiant energy from light bulbs using a photovoltaic cell. Energy emitted by incandescent bulbs followed a very predictable arc depending on bulb wattage. The CF bulbs all produced almost negligible amounts regardless of wattage.

        I understand where you are going with this post, and I understand why there is so much pushback. Sadly, most these days don’t want to critically examine policy. There is nothing inherently wrong with CF or incandescent or LED bulbs. The problem is in mandating the use of one or the other. Any such mandate will have unforeseen negative consequences, just as all mandates eventually do.

      • Chris Lowe says:

        Only 90% of the energy from an incandescent bulb is turned into heat. There’s also the issue of how well that heat is circulated. Most lamps are pretty poor at doing that.

      • What happens to the other 10%? It turns into light, which then turns into heat when it hits a surface. As long as your light isn’t shining out the window, that happens inside your house.

        Anyhow, my intial point was not that compact fluorescent bulbs are a hoax or anything like that. It’s just that the benefits are not the same everywhere. The simple graphic that leads in the article equates one compact fluorescent bulb with nine incandescent bulbs, but during Seattle’s winter, the energy savings depend on how well the air in your house circulates and whether you heat with electricity or gas.

        Similarly, buying a new, fuel-efficient car makes sense if you drive a lot, but perhaps not if you don’t. And wider tires on a bicycle have greater benefits on some roads than on others. A nuanced view is important to get good results.

        I am flying to France for PBP, visiting family, and doing research for Bicycle Quarterly. The impact of that single 12-hour flight is greater than all my light bulbs and car use for the entire year. I wrote about that here.

      • Erik says:

        Dear Jan and others,
        Just to clarify:
        – incandescent bulbs only produce 2% light and 98% heat
        – most electricity is produced in gas or nuclear power plants, which have an efficiency of 60% (gas) and 30% (nuclear).
        – a standard (in Europe at least) condensing gas boiler has a heat efficiency of 98 %. (sometimes claimed to be 110% but this is theoretically not correct.
        So is the heat, produced by a incandescent bulb, lost? Not entirely, but it has an heating efficiency considerably lower than that of a normal heating system (0.98*0.6 vs 0.98), and is not emitted in an efficient location (high in the room). Am I claiming we will safe the world with fluorescent bulbs? Not at all, they greatly reduce the power that is being used for lightning, but that is only a small part of our energy consumption. However the fact that it halves the power consumption without making big sacrifices makes it an interesting action to take. The color difference you claim is entirely due to the fluorescent matter that is being used, in practice it is possible to find fluorescent bulbs that emit light that has the exact same characteristics (color temperature and color rendering index)
        However, apart from all the stuff you use or buy, your energy consumption is mainly dependent on your on behavior. Our total energy consumption consists of transport, housing, food, each representing about a third of the total.

    • Solomon Gursky says:

      While I am not an expert on these things, my understanding is that electric resistance heating in general is less efficient than other types. If you have to stick to electric, than a heat pump system (which operates more by transferring thermal energy) can be vastly more efficient in moderate climates like Seattle. And combustion systems using natural gas or oil are much more efficient (or at least much more cost effective) in Northern climates. Instead of burning gas to heat water to make steam to turn a turbine to create electricity, and then trasnmitting that electricity over a long distance to your light bulb or other resistance device to create heat, a furnace in your house just burns the gas to heat your house directly. If electric heat was cheaper, in-home furnaces would be a lot less prevalent in New England.

      • I was basing my analysis on the simple fact that energy cannot be destroyed, but only converted from one state to another. OK, if you have canned lights in the ceiling, you probably are heating your attic…but you have to heat something to consume the electricity. And yes, power lines also emit energy – you can hear it in the rain. But gas lines also leak, etc., etc. So we could get into the finer parts of “It depends where your lights are installed and how your electricity is generated and how your house is heated”, but the main point is that all these are factors that will play an important role in the analysis.

        Another cycling analogy (yes, this is a bike blog) is the question whether aerodynamics or rolling resistance offer more important gains in speed. For a very fast rider, it’s probably aerodynamics, but for a slow rider it’s definitely rolling resistance. When you add the fact that it’s hard to improve aerodynamics by more than 5% for a rider who already has a “sporting” position on the bike, whereas tire resistance can vary by 100%, then you complicate the picture further, it’s not even certain that for a fast rider, the bigger gains may not come from switching tires as well…

      • John B says:

        Solomon, electric resistance heating is VERY efficient. Oil, gas or propane lose some heat up the chimney, depending on the efficiency of the furnace. The disadvantage of electric heat is its higher cost.

  4. afeman says:

    Jan,
    Your example with the light bulbs only account for the heat energy produced at the end of the line, which is valid only if you heat electrically. Against non-electrical heat there are other factors like line loss, which I understand can be tens of percent. And it’s been years since I’ve had trouble getting warm CF bulbs in warm colors. Maybe yours have lived too long?

  5. Michael Hook says:

    I agree with most of your points, but I question the one about fluorescent bulbs contributing to seasonal affective disorder, speaking as someone who experiences the symptoms quite strongly in Canadian winters, during a stretch of cloudy days, or even if I’m too busy with indoor activities to get outside much. People often give me odd looks when I say that I actually dislike the yellow color of incandescent lights — I much prefer lights that better approximate sunlight.

    I found this to be a fairly clear introduction to different light colors:

    http://www.eejitsguides.com/environment/esbulbs.html

    After reading that, I think I might look for some 5400K bulbs and try them out. I may well be wrong, but I suspect that the main reason 2700K lights are so popular is that they used to be the only ones commonly available and we’ve just gotten used to them.

    Another one:

    http://www.topbulb.com/find/full_spectrum.asp

  6. Steve says:

    You need to factor in the fuel source and transmission losses of the delivery systems to get the full picture in your light bulb example.

    In most of the US (even in the hydroelectric happy Northwest) you’d be replacing coal emissions used to generate the electricity with natural gas emissions. Natural gas produces less CO2 and coal also produces sulfur and nitrogen emissions.

    Electrical system losses range between 6-8% just getting the electricity from the power plant to your house. Natural gas systems lose about 1-2% in getting the gas to your house. So generally if you have one of the newer 90% AFUE gas furnaces you’re probably still close to the same overall system efficiency to produce the BTUs from the incandescent bulbs.

    So on balance, you’re better off with the fluorescent bulb. Even though you’re losing the heat produced as a byproduct, you’re replacing it with a cleaner burning fuel (if you’re using natural gas) that on balance is just as efficient.

    And the real breakthrough is going to be switching to LED bulbs. No mercury, better color rendition, and longer life.

    • It’s hard to say whether electricity generation or the mining of natural gas cause more pollution. My point was the most advice simply equates the extra energy consumed by incandescent bulbs as wasted energy… but that in the real world, it’s not that simple.

      • Michael Richters says:

        Indeed, it’s not that simple. But you’ve grossly oversimplified the situation yourself. First of all, by far the largest percentage of electrical generation in the United States comes from coal-fired power plants, which are far less efficient. Coal plants have an average efficiency of ~33%, and constituted 45% of the electrical generation in the US in 2009 (next was natural gas, at 24%, which is only ~50% efficient). Then there are transmission losses. Also, incandescent bulbs aren’t really very good at circulating heat to where it is needed. You did mention ceiling fans helping with that problem, but they also use electricity, and generate very little heat.

        On another note, though it’s true that compact flourescent bulbs contain some mercury (in tiny amounts), fossil fuels (coal, oil, gas) also contain mercury, and over the lifetime of a CF bulb, substantially more mercury would be emitted by power plants — into the environment — by using incandescent bulbs instead. The mercury in the CF bulb stays there, unless it’s broken. On balance, CF bulbs are much less dirty environmentally (as far as mercury is concerned, anyway), even if they break. The mercury problem with them is that, if they break, the mercury can be aerosolized, making it very locally toxic.

  7. valsidalv niksul says:

    Come on, Jan, we all know that an incandescent bulb is a pretty darn inefficient way to heat a room :-)

  8. While I agree with your central thesis, I do feel compelled to point out a few key points you’re omitting in your example of your current car versus a Honda Fit. You postulate a modest reduction in gasoline consumption (39 gallons per year) at the cost of the environmental impact of disposing the car and the manufacture of the new car. That I don’t dispute. However, it’s not only an issue of gasoline consumption. For every mile you drive your 19 year old car, you’re also producing far more emissions than you would with a new car that must comply with much more stringent emissions requirements. I don’t know the exact numbers, but in terms of CO and other combustion byproducts, as well as particulate emissions, new LEV and PZEV standards are much more stringent than old standards. That should be factored into your comparison, in order to create a more complete “big picture”.

    As for your Texas versus Seattle comparison, do you mean to say that you rarely switch on your lights in seasons other than when you have to switch your heat on? Even here in the Northeast, we only use our home heat between November and April. Surely in Seattle, with a properly insulated home, you should only need to heat your house within an even narrower window of time. And another factor that should be considered in the “big picture” is the source of the energy: What is the net environmental impact of natural gas distribution compared with electricity production? And how significantly is the ratio of those two impacts skewed by a switch from incandescent to CFL? I’m not trying to make the argument that CFLs are better than incandescents in terms of environmental impact; I’m only arguing that by not considering the environmental impact of the energy sources driving your home heating and your lighting, you are not looking at the big picture.

    • AC says:

      Living in Vermont, which is definitely known more for its winters than its summers, I still find myself loving my CFLs in the summertime. I don’t feel my face melting off reading a book by a table lamp anymore.

  9. Chris Lowe says:

    Several of your arguments on CFLs are incorrect.

    The amount of heat given off by an incandescent bulb is nominal and switching to CFLs (or even better to LED) will still save you energy. In a cold climate it won’t be the 70+% savings that CFL advocates claim but it will almost certainly still be a savings and not the zero energy savings you claim. Seattle City Light actually addresses this very issue here: http://www.seattle.gov/light/conserve/resident/cv5_lw2.htm#faqs The CBC also ran an article (http://tinyurl.com/3pav68q) where they found that even in Winnipeg – which is much colder than Seattle – CFLs still saved 17% on energy. Keep in mind gas is cheaper than electricity. Also most light bulbs are up on the ceiling or shrouded by a lamp shade and have no means with which to circulate the heat they generate making them pretty inefficient heating devices. If you were to switch to CFL bulbs and see an increase in your heating bill it’s almost certainly because your house is poorly insulated to begin with and simply adding weather stripping to your doors and windows will change that. Relying on the heat from incandescent bulbs would be a very poor way of compensating. Of you’re really concerned about heating and energy savings your best solution is insulating your walls with recycled insulation (usually made from old blue jeans) which uses zero energy and is often lacking in most of the older homes found in Seattle. Insulating walls is a cheap (though messy) DIY job. I do think that CFL bulbs have been wildly oversold and they’re not nearly the energy savers that their advocates make them out to be. However they do still yield a savings.

    As for the color issue, this kept me from switching to CFL for a long time but you can now find bulbs in the 2700 degree Kelvin range which is the same as an incandescent bulb. After some trial and error we eventually found bulbs that have a nice, warm light and start up quickly (another big problem I had with CFL bulbs). You can also switch to LED bulbs which avoid the issue entirely. We plan to start replacing our CFL bulbs with LED bulbs now that the costs are starting to drop.

    The mercury issue is mostly a non-issue. The amount of mercury in a CFL is 1/100th what you’d find in a traditional thermometer and chances are there are many other far more toxic substances already in your home (like the asbestos found in old tile adhesive or the lead found in old paint). You can also recycle them for free at most hardware stores and many drug stores (I know here in Seattle Bartells takes them in). LED bulbs have no mercury in case you’re really concerned.

    • We soon get into splitting hairs, but I turn on the lights in the room where I am and read a book, so the light bulb heats the immediate area where I am, whereas my (typical American) heating system heats the entire house equally. Yes, I could install radiant heating that allows me to heat individual rooms (like they do in Europe), but as a matter of fact, few American homes are equipped that way. So in my case, the light bulb is heating the place where I sit, and I can keep the rest of the house cooler.

      • Chris Lowe says:

        Radiant heating is a great example of where the nuanced view kicks in. When we bought our current home it still had the original 1961 furnace in it. The tank was nearly empty when we moved in and within 2 months we used up the last of the oil and figured this would be good time to upgrade the heating system. We looked at radiant heating in addition to a high efficiency gas furnace. Putting in radiant heating throughout the house would have required us to rip out the existing wood floor and add in new flooring. In addition to the cost it would also required tossing perfectly good flooring and making new flooring. Having gas plumbed in was free since we also switched to a gas powered tankless water heater and a gas cooking range (in Seattle they add the line for free if you convert at least three appliances). If we were building the house from scratch radiant would make more sense.

        There’s also the Jimmy Carter solution of putting on a sweater. Carter took a lot of flack for that but he was absolutely correct!

      • valsidalv niksul says:

        If you turn on a standing lamp with an incandescent bulb in the room where you’re sitting and reading, the heat the bulb generates will rise to the ceiling and pool there, rather than heat the area where you are, which is much closer to the floor than to the ceiling. If it’s an overhead light you use, you’re more effectively heating the crawl space or the room above than the one you’re occupying.

        Not to derail the thread, but good luck at P-B-P.

  10. charlie white says:

    I too live in Seattle, and I sometimes turn on my lights when my furnace is not running. I try to run my heat as little as possible, not every time I have on lights do I want the heat. In fact, I would say about 75% of the time I don’t want the heat/wasted energy.
    As for the fuel efficient car, you are mostly correct. If you don’t drive much, and are happy with your existing car (assuming you own one) don’t buy a new car for the sake of saving energy. However, the majority of car owners purchase cars out of desire instead of need. So, if you are going to buy a new car anyhow, why not buy the more fuel efficient one?

    • So, if you are going to buy a new car anyhow, why not buy the more fuel efficient one?

      Absolutely. It’s like bikes: I don’t worry about whether my current bike is not optimal, but when I buy a new one, I might just as well get one that is better.

    • Ford Kanzler says:

      What’s the impact formula for people purchasing used, high-mileage cars like a 20-year-old Honda Civic that gets 35mpg?

      • It depends how much you drive. If you drive 40,000 miles a year, then the impact of driving will quickly outpace the impact of manufacturing. Also, if you assume that most cars are driven about 200,000 miles or more during their lifetime, it makes sense to make them as fuel-efficient as possible. So buying a new gas-guzzler is the worst-case scenario. If everybody had bought fuel-efficient cars 20 years ago, there would be many more available used today.

  11. John says:

    Your overall point I agree with, Jan, However as others have pointed out, the cfl analogy just isn’t correct. There are, and were energy engineers involved that have considered the full impact of the cfl retrofit. We have considered their lifetimes in different climates and in different applications, the delta T, fuel prices, mercury, electricity prices, the efficiencies of furnaces, lumens, maintenance, efficacies, CRI, CCT, and on and on. Even here, in cold and snowy Vermont, the cfl makes a lot of sense financially and environmentally.

    As others have alluded, I think LED’s will be lighting the future due to better directional lumen manipulation (less lost light), better efficacies, excellent CRI, CCT, elimination of Hg, and much longer lifetimes (especially in cold climates, or continuous on/off scenarios)… but I digress.

    Hopefully the take-home point of the post wasn’t lost by too many after reading this inaccuracy.

    • phr3dly says:

      In principle I support lightbulbs with lower “waste” energy usage (heat). Jan makes the point about their use in Seattle, but of course if one lives in a climate where A/C is used, then the opposite is true. The waste energy of the lightbulbs packs a double-whammy. You waste energy heating a warm room, then waste more energy cooling it.

      In a perfect world, light bulbs would light. And do nothing else. Heaters would heat, and do nothing else. But we don’t live in a perfect world. In the world we live in there are tradeoffs.

      The tradeoffs with CFLs include:
      * Highly variable bulb lifetimes (despite what the marketing literature says)
      * High up-front cost
      * High disposal cost
      * Less “point heating” for those in cool climates, requiring use of space heaters or inefficient whole-house heating.
      * Poor light temperature (again, despite what the marketing literature says)

      Many intelligent and thoughtful people have considered CFLs, including their alleged long-term cost savings, and chosen incandescents because they are a better fit for a particular use-case.

      But as you point out, this is missing the forest for the trees. Jan’s point in general was not about lightbulbs, but rather that individuals may have different cost-benefit analyses than policy makers (or lightbulb engineers).

      • John says:

        Excellent points fr3dly, however a few items I’d like to clear up.

        The variable bulb lifetimes and poor light temperature issues you speak of are product specific concerns. Just like any other thing, there is a large variation in product quality between different manufacturers and even within those product lines. An Energy Star rated product is at least known to have passed a rigorous series of testing and should be sought when purchasing cfls. However, if it’s to be located in cyclic on/off scenarios, in cold temperatures, or you plan to use a non-PAR cfl lamp in a recessed can; there are better lighting options available.

        Prices will eventually come down on LED’s to a point that will make much of fluorescent lighting outdated.

        http://spectrum.ieee.org/semiconductors/optoelectronics/silicon-is-key-to-quest-for-5-led-lightbulb

  12. Phil Miller says:

    To bring back your original point and feed it back to the light bulbs: An incandescent light bulb in the ceiling is an inefficient heater. The heat is already up there (ummm heat rises?) But if you put one in your ceiling fan, then the heat circulates. Need bulbs for your can lights? Use CFI’s. Need on in a desk lamp in the winter, use an incandescent. Need on above your bed for reading? Use an LED. Now if your spare light bulb storage cabinet isn’t bulging yet… You don’t have enough products that aren’t being used! (The marketing doctors have struck again… They’ve gotten you to buy things you aren’t even using yet! :-)

    • phr3dly says:

      This is an example where the engineering analysis fails — from an engineering standpoint an LED makes perfect sense for a bedside light. From a practical perspective, spending $40 for a LED lightbulb instead of $0.39 for a 40W incandescent that will last virtually forever in that use-case is a poor economic decision.

      Much like with cars (for a typical driver, replacing a 40 MPG car with a hypothetical 10000 MPG car will save less gas than replacing a 15 MPG car with a 25 MPG car), saving energy in a use-case where energy use is already very low is a fool’s errand.

      In CS this is referred to as Amdahl’s Law. It can be summed up as you shouldn’t waste time optimizing stuff that represents a vanishingly small fraction of a problem.

  13. Gert Pagter says:

    I will not comment that much on the light. Apart from warn against the cold light, which does not only give You the “winter blues”. It also increases agression.
    About tyre width and pressure. A german cycling magazine http://www.tour-magazin.de/
    has had some tests over the years with varying tyre widths and pressures.
    As I recall the results.
    – Wider tyres at same pressure have lower rolling resistance, and are a little bit more comfortable (Test was made with 28, 25 and 23 mm Continental Grand prix 3000 or 4000)
    – Increased drag from wider tyres are not measurable until speeds of 35-40km/h
    – Test with a 23 mm Continental Grand prix 3000 ridden at 6 bar (87 PSI) and 8 bar (116 PSI) showed that the lower pressure dramaticly reduced the shock forces in the saddle post. At the same time the expected increase in energy consumption due to the higher rolling restistance was barely noticeable. Probably because the tyre at lower pressure had better road contact.

    So in P-B-P, where the roads are not that smooth I will be riding 25mm tyres at 6 bar (87 PSI). It will not reduce my speed much. But it will increase the comfort a lot.

  14. cept says:

    I recommend the Science Friday podcast piece about CFLs and lightbulbs: http://www.podtrac.com/pts/redirect.mp3/traffic.libsyn.com/sciencefriday/scifri20110715-hr1.mp3

  15. Steve Palincsar says:

    I’d like CFLs a lot more if they gave the service life that’s claimed for them. Instead, I’m seeing roughly 10% of the claimed life.

  16. This discussion highlights the complexity, and the fun, of trying to account for the implications of our actions, and our choices in life. Not easy. It’s the Human Condition. It’s the joy of Accounting, which isn’t bookkeeping; it’s about value(s).
    Also: All the best to the Riders of PBP 2011! Hip, Hip, Hurrah!

  17. don cardwell says:

    It seems the standards for energy efficiency were based on the advantages of the halogen-incandescent lamp over the garden variety incandescent, about 30% more efficient. Halogens (1950s technology, really) have begun appearing in all manner of useful design (including conventional ‘light bulbs’) and happily fill the gaps between CFL, Fluorescent, and LED. By 2020, lamps will need to produce 40 lumens per watt, about what CFLs manage, and perhaps by then LEDs will be perfected. In the meantime, Halogens offer an immediate improvement over old incandescents with none of the drawbacks.

  18. TS Wu says:

    The examples discussed above are basically forms of LCA or Life Cycle Analysis, in which one attempts to calculate the full environmental impacts of making, using and throwing away a product. ‘Course, when you start trying to calculate the energy used to build the truck used to mine the steel used to make the… it’s no wonder to me why a presenter at a conference on this topic I attended years ago quipped: “LCA: the academician’s dream, the lawyer’s nightmare.”

    As with many things, you’re taking something with many attributes and trying to roll them up into a single attribute- like grade point average- a single number that represents how well you did in school. I suppose you might do the same in choosing a bike. Perhaps Jan your point is that one should know what their goal is given the type of terrain or situation of the ride, and choose accordingly. The oft-heard critique of “racing-bicyclitis” is arises from matching a racing goal with a non-racing riding situation.

    PS- Speaking of cool, blue light, there was an interesting NYT article about studies that show LED powered lights that tend to be heavy in the blue spectrum have been shown to reduce the amount of melatonin produced. I know I much prefer to keep my eyes off the screen just before bed: http://www.nytimes.com/2011/08/11/garden/almost-time-to-change-the-light-bulb.html

  19. GP says:

    Personally, I plan to slowly transition directly from incandescent bulbs (I like the Reveal brand for its noticeably less yellow light) to LEDs, where appropriate. I’m not rushing out to do anything at the moment, and I don’t have a single CFL in our home….
    In the mean time, I’ve replaced all of our home’s windows and doors with triple-pane Pellas with low-e glass, argon, etc. and re-insulated our attic to R49, in addition to finishing off our basement and using R13 in all of those walls. Next month, we are switching to a modulating two-stage 95% AFUE furnace with a DC motor from our old 90% one with an AC motor, and from an 8.0 SEER a/c unit to a 20.0 SEER one. Next on the list (when we can do it) is a new refrigerator, as ours is for sure not an efficient one. After that, I’ll target replacing the washing machine and dryer with significantly more efficient units.

  20. Sorry Jan, while you are SO right on so many things you’re wrong on the CFL vs incandescent question. Here’s a quick summary: http://thinkprogress.org/romm/2008/03/26/202477/please-dont-use-incandescent-bulbs-for-heating/ In essence, the post suggests you take one step further back than you did, and examine the even bigger picture. :)

  21. Ford Kanzler says:

    Similar big picture concerns exist around waste recycling. Some perspectives point to there being more pollution created and energy wasted on recycling than is saved in the process. Seems a shame since people likely get some psychic rewards from feeling like they’re doing some good by recycling. Consumer goods packaging practices have a long way to go in helping with this problem. Consumer products companies likely do not pay for or even pass on the full cost of dealing with their packaging or the disposal of the goods after use. I understand this requirement is now being enforced in Europe.

Comments are closed.