Velo News reports that Marcus Burghardt averaged 309 watts of power for a three-hour section of the stage. Looking at CNET's handy table of power consumption in the various modes of HDTV's, once you get to the 42-inch size, you're in the range of his power output. Add another 38 W or so for your surround sound system and around 20 watts for the cable box, and you're pretty much guaranteed to be consuming more power with those electronics than he averaged to slog himself 120 or so miles. That's also similar to seven 75-watt incandescent light bulbs or seventeen 18-watt compact fluorescent bulbs (equivalent light output). Almost all of those 300 watts end up as heat in your house. On these hot days of the summer (depending where you live), that's heat your air conditioner has to remove to keep you cool.

Evidently, his highest 5-second power output was over 1,300 watts. A typical hairdryer or coffeemaker will have a 1,500 watt heating element in them. That might be somewhat humbling, as his superhuman effort is outdone from an energy perspective when a cup of coffee gets brewed. On the other hand, I'm pretty thankful I don't have to exert that much effort to have my morning coffee.

I have a chart hanging in my office that shows the time to exhaustion for a range of power output on a bike. I wish I knew the source, but I can't find it right now. In any case, it has two curves: healthy humans and first class athletes. Obviously, the riders in the Tour are elite athletes, and most of the rest of us are nowhere close. 300 watts lands somewhere around 7 hours on the first class athletes curve. However, it is in the 15-20 minute time to exhaustion for healthy humans. The chart ends at 373 watts (0.5 horsepower), so the 1,300 watt level is literally off the chart. :)

For healthy humans, the 8-hour time to exhaustion relates to around 75 watts. Think about spending your whole workday pedaling a bike generator (assuming no generator inefficiency) just to power a 75-watt light bulb or perhaps two 4-foot T-12 fluorescent tubes (typical 34 or 40 watts each).

A last bit of perspective is to look at a automobile engine. What do most cars and SUV's have as their rated horsepower? I think it's something like 150 to 300 horsepower for most mainstream consumer passenger vehicles. That's about 112,000 to 224,000 watts (112-224 kW). That's pretty stunning. I know that under normal conditions, the power output is less than that, and that the rated horsepower is measured at the flywheel and not at the tire-to-road interface, but it's sort of irrelevant to this sort of order of magnitude look at things.

OK, now that we all feel guilty, go ride your bike somewhere and shut off that light when you're not using it! :)