Fun facts, kinda OT, for the bored Options

[lapuwali]

1 US gallon of gasoline contains 104,000 BTUs of energy.
1hp = 2,540 BTU/hour of energy consumption.

A typical car requires about 9hp to cruise at 60mph, given aero loads and rolling resistance from tires.

So, if engines were 100% efficient at extracting energy from gasoline, you'd get 273 mpg at 60mph in a typical car. Since most cars actually get less than 30mpg, most engines are extracting roughly 10% of the energy in the gas and applying those to actually propelling the car. Most of the energy is being thrown out as waste heat directly out of the exhaust, or in heating up the coolant, the engine itself, the gearbox, and the tires.

btw, hydrogen has 180,000 BTU/US gal, so if a liquid H2 fuelled engine were produced that only had the same efficiency as a 27mpg gasoline engine, you'll see 45mpg typically.

Pure ethanol has only 70,000 BTU/US gal, for only 18mpg. E85 would bring this up to 20mpg. Britt noted E85 where he lived was $2.10/gal v. $2.58/gal for gasoline, meaning E85 costs 81% as much, but only takes you 74% as far...

Now, as for the efficiency of a Mr. Fusion powered car...

[lapuwali]

QUOTE (sgomes @ Aug 23 2005, 07:30 PM)

QUOTE (lapuwali @ Aug 23 2005, 07:09 PM) electricity is also a "net loss" form of energy storage. Please please please I'm not trying to start an argument... I'm just curious as to what you mean by this statement. Aren't ALL forms of energy transfer in the universe "net loss"? Some more than others.

Hey, I don't mind a good argument, and I can keep it civil. (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

That statement is roughly as true as saying "hydrogen is a net loss", though one has to do a lot of hand-waving to get there...

Since, as said, entropy is the ultimate process here, and we're ALL using power that somehow came into being through a process we don't understand, and is winding down all the time (no matter what we do), then everything is a net loss. All we can do is convert things from one form into another. We can take solar power and convert it into electricity and store it chemically in a battery. How much power does that take? Do we count all of the wattage coming off the sun? How efficient is THAT process? Where exactly do we measure the losses? Do we NOT count all of the Sun's energy that's not even falling on the Earth?

In other words, my reaction to "that's a net loss" is "so what?". And if I bend and twist terminology enough, I can say (and defend) the idea that hydrogen is "renewable", since it isn't destroyed in the process of being used, and can readily be converted back into a useful form in a timescale that's reasonable, using a level of power that's reasonable.

If none of that made any sense, well, it's late...