Friday, May 29, 2009

A Congressional Referendum For Daytime Padiddle…

Remember Padiddle? Punchbuggy’s wonderful little cousin where one is beaten severely for being the last person in the car to notice an oncoming auto with one headlight burned out? Well, The European Union has announced a plan to have all automobiles in Europe equipped with “daylight running lights” which in effect is driving around with headlights on all the time. This got me thinking. What if we did this in the US? It’s been proposed. They say the effect on gas mileage will be minimal at best… Since I get nervously suspicious every time they start telling me what matters, I decided to whip out my calculator and start looking at the math…

…It is far, far from minimal...

In order to understand the magnitude of the effect this law would have in the US, we need to know some basic facts and then agree on some assumptions. I will be very conservative in my approach so all you out there who feel obligated to doubt the conclusions of this post (an attitude I respect) you can at least know the conclusions as far as I can tell are best-case – meaning it could be (and probably is) much, much worse.

Let’s start with the wattage of the average auto headlamp: 55 watts. Since most vehicles on the road have two working headlamps, that would be 110 watts per vehicle.

In order to complete our analysis we need to know how many miles are driven in the US annually. According to the Federal Highway Administration and the National Highway Traffic Safety Administration (NHTSA) 3,029,822,000,000 miles were traveled in the US in 2007. That’s 3 trillion with a “t.” (If you need some reference on the magnitude of that number see my earlier post Million vs. Billion – A Drift To Innumeracy from October of 2008.)

We will assume for our purposes that the average speed across all vehicles is 30 miles per hour (it’s probably lower, but we’re going conservative here.) 30 miles per hour results in 2 minutes elapsed per mile traveled. This means total travel time in the US is 6,059,644,000,000 (6 trillion) minutes or 100,994,066,666 (101 billion) hours on the road annually.

Assuming (again, conservatively) that vehicles were travelling during the daytime hours only half the time on the road our calculation results in 50,497,033,333 (50.5 billion) daylight running hours. At 110 watts per hour, headlamps will use 5,554,673,666,630 (5.5 trillion) watt-hours or 5,554,673,667 (5.5 billion) kilowatt hours annually. The entire United States uses that much energy about every 15 hours.

Next, we have to determine how many kilowatt hours can be converted from a gallon of gasoline. This is a little trickier. An automobile must put a gallon of gasoline through two conversions before it can use it to light a light bulb. A gallon of gasoline contains 60 kilowatt hours of chemical energy. Your car engine converts that chemical energy to mechanical energy through the process of internal combustion. However, that process is ridiculously inefficient (are you listening Detroit?) and only 25% of that original chemical energy is retained as mechanical energy and 75% is lost as heat. Therefore, 60 kilowatt hours of chemical energy is converted to 15 kilowatt hours of mechanical energy.

But we’re not there yet. Your car must convert that new mechanical energy yet again before it can light those bulbs! The second conversion takes place in the alternator. Your alternator must convert that mechanical energy to electrical energy. The alternator is more efficient, but still loses 30% of the converted energy. So, only 70% of the mechanical energy is retained once it is converted to electrical energy. Therefore, from one gallon of gasoline, your automobile will produce a whopping 10.5 kilowatt hours of electrical energy.

When we divide the 10.5 kilowatt hours into the the 5,554,673,667 (5.5 billion) kilowatt hours needed annually to keep the headlights on in the US during the daytime we reveal that it will require 529,016,540 additional gallons per year. At $2.50 per gallon, that’s $1,322,541,350.00 ($1.3 billion) more spent annually by Americans for their gasoline…

The fossil fuel waste argument is only one aspect of the stupidity behind this proposal. For example, consider this: The average automobile releases 19.4 lbs of CO2 into the atmosphere per gallon of gasoline burned. Daylight headlights would result in an extra 10,262,920,876 (10.25 billion) lbs of additional CO2 into the atmosphere per year…

Still not convinced? How about this one: The above figures only factor in the headlights. The current proposals call for headlights but not any other lights. I ask which will be greater – the number of accidents prevented because the headlights are on, or the number of accidents caused because drivers (the same idiots that make this debate even necessary) are only paying attention to their headlights and forget to actually turn their lights on at night driving around with no rear lights or side lights? The solution, according to some law-makers, is to have all lights on constantly – sure Einstein; just double all the above figures – problem solved.

The only real upside I can see is more opportunity for games of Padiddle and the advantage that daylight will bring during those very serious matches. No more beatdowns because of those false-positive misidentifications of motorcycles – you’ll see’em coming… GO Congress! Instead of pulling out in front of cars at 1:00 pm because they’re somehow harder to see nowadays than they were 15 years ago (?!), we’ll all be beating the living shit out of each other like some kind of mobile cage match while screaming “PADIDDLE!” and driving head-on towards the moron with the one good headlight… awesome.

How about we just enforce the laws that say we have to freakin’ learn to drive, hmmm?? Is that too tough? Really…?


  1. Hey, I remember padiddles! :)

    Although, I can't agree with your argument on this rant.

    It doesn't take more fuel, releasing more CO2, to have your headlights on...they're driven by the electical system of your vehicle which is powered by your battery and the alternator, which provides power to run your electric items and recharges your battery while the vehicle is running.

    So, in reality, it will only result in more burned out bulbs, and possibly a few more burned out alternators, which need to be manufactured and transported to retail outlets. Also creating more waste to add to our already overflowing landfills. So, although I don't agree with your stated argument, there will be side affects of this change, just not as dramatic as your claims...

    ...IMO. Hey, I am allowed to have one, right? ;)

  2. Comments and opinions are always welcome!
    But I think you've made a mistake in disagreeing with me on this one. Headlamps really do use more fuel. You are correct in your assumption that the headlamps are driven by the electrical system. But, the alternator (unless yours is magic) is is powered by your engine's drive belt. Attached to the alternator is a voltage regulator. The alternator in your vehicle does not constantly supply voltage to the automobile - only when the auto needs it. The voltage regulator controls when the alternator charges and doesn't charge. When the available voltage drops below 13.5 volts, the regulator signals the alternator to start charging. When the available voltage climbs above 14.5 volts, the regulator signals the alternator to stop charging. This is how voltage output from the alternator is regulated. When headlamps are on they obviously draw on the available voltage. The total voltage necessary to power the automobile's electrical devices is increased. Therefore, the alternator must charge more often, exerting more load on the drive belt. This means your engine must work harder to turn the alternator more often... and... wait for it... burn more gasoline! (and cough out more CO2).
    Great points by the way in the second half of your comment... the fuel consumption from simply transporting all those new bulbs! Brilliant... wonder if we could calculate that??