First, why you should believe a word I say - I've spent the last five years (my college life, basically) working with solar-electric vehicles. I'm an electrical engineer by profession, and an auto enthusiast the rest of the time. I'd love it if my truck was powered by a small tokamak under the hood cranking several cool megawatts into a couple of traction motors on the axles. Oh yeah, and I want to get 1000 miles/gram of deuterium. It'd be a lot easier to fix when it breaks than a bigass V8 with tons of moving, wearing parts. Unfortunately, nobody yet offers such a powerplant that fits in the form-factor of a Chevy smallblock.
While lots of you would like to believe that it's all a big conspiracy by government, auto manufacturers, and big oil, the simple truth is that it isn't. It's an engineering issue - gasoline simply continues to be one of the best all-around compromise solutions for our current situation. While I know that's flame-bait, here's my reasoning (these should be fairly close, but as I should be working right now, I'm trying to hurry - if I screwed up a calculation, please dispute it...):
Typical Energy Densities in kWh/kg Hydrogen...32.9 Gasoline...14 CNG/LNG...9.8 Ethanol...2.8 Pb Acid Batteries...0.04 NiCd Batteries...0.08 NiMH Batteries...0.12 Li Polymer Batteries...0.23
Hydrogen is better, but it's an issue of producing/manufacturing/distributing it. Electrolysis isn't that efficient, and the energy still has to come from somewhere - free hydrogen just doesn't occur naturally, so it's more of an intermediate stage between some other form of energy and something you can haul around. By the time you factor in the efficiency of electrolysis (the only feasible process for mass hydrogen production that I'm aware of - anybody more knowledgable about this than me?), it's about the same energy density as gasoline, and you've wasted 30% of your input energy. Same to worse with most other alternative chemical fuels.
Solar? Forget it - even if photovoltaics were 100% efficient (which isn't and won't ever be possible), that's still only 1kW/m^2 average in the US. (Practical terrestrial grade cells are currently 15-17% efficient and about $9US/W. By the time you get them encapsulated and strung together, they're about $25-30US/W. Prohibitively expensive, big, and most of all, fragile. Imagine instead of just replacing a panel and doing some painting next time you're in a wreck, replacing a $50,000 array as well, because it has hairline cracks all through it... ouch...)
It's fairly obvious that current batteries are not practical for any long-range vehicle, and especially not one designed for extended (multiple refuel/rechargings per day) as batteries just don't recharge that fast. Piling in enough batteries to give a common sedan adequate range for most Americans out here in the West (the Eastern megalopolis is another issue, with the close proximity of everything). On average, I put on about 1k miles/week, and that's more than any currently-available system other than ICE/gasoline can practically handle.
So, why not build an ultralight car and just reduce the amount fuel it needs for propulsion? Twofold: 1) ultra-light probably means moving away from steel, which significantly raises the cost and 2) ulta-light probably can't take much punishment without being irreparably damaged or injuring the occupants.
While I don't dispute that gasoline is not the final solution, for right now it's the best we've got. Certainly it can be made less-poluting (better engines, better emissions equipment, oxygenated fuels), and I'd be willing to pay a bit more for that. And I'd like to see more time and research thrown at improving alternative fuel sources [Especially my dream fusion tokamak I asked for earlier...;)] Just right now I don't think it's practical to switch most countries over. The Eastern US and most of Western Europe I think are notable exceptions, though - because of the small distances involved in normal travel, vehicles with less range and longer recharge/refuel cycles are practical. Anybody else from got any thoughts on this?
Quickie SUV Anti-Rant Just because all you anti-big-truck fanatics are bitching in here: Let it be said I do drive a large truck (1993 4WD K-Blazer) and the only way you'll get it away from me is to pry it from my cold dead hands. I don't care what gas costs, that's really irrelevant to me. The fact that I'm not cramped into a little itty bitty car shell is the only way I can possibly stand doing 1200 mile days (IL to CO). I've always driven large trucks (up to and including large tractor/trailer rigs, I used to hold a CDL, but no longer have a use for it...), unlike most of the yuppies buying SUVs these days, I actually use mine for hauling and towing and back-roading in places that would kill cars dead. Most importantly, I also realize that I'm driving a 3-ton kinetic weapon, and if I make mistakes at speed and I hit another vehicle, most likely someone is going to die. Just having moved to Colorado for work, I'm surrounded by people who don't understand that a K-Blazer/Yukon/Tahoe/Suburban is a full-sized truck and drives like such, not a passenger car. They also don't realize the implications of making a mistake while driving such a thing. When handled and maintained correctly, they're a beautiful pieces of engineering that can go places that eat little cars for lunch. The problem isn't the vehicle - it's the stupid fscking people who don't fscking know how to drive such a creature properly and responsibly. (Sorry to check my fs twice in one sentence...) They make the rest of us look bad. Did I mention that my SUV used to run Linux (for a vehicle telemetry project)?:) End of SUV-hater-hating rant.
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While lots of you would like to believe that it's all a big conspiracy by government, auto manufacturers, and big oil, the simple truth is that it isn't. It's an engineering issue - gasoline simply continues to be one of the best all-around compromise solutions for our current situation. While I know that's flame-bait, here's my reasoning (these should be fairly close, but as I should be working right now, I'm trying to hurry - if I screwed up a calculation, please dispute it...):
Typical Energy Densities in kWh/kg
Hydrogen...32.9
Gasoline...14
CNG/LNG...9.8
Ethanol...2.8
Pb Acid Batteries...0.04
NiCd Batteries...0.08
NiMH Batteries...0.12
Li Polymer Batteries...0.23
Hydrogen is better, but it's an issue of producing/manufacturing/distributing it. Electrolysis isn't that efficient, and the energy still has to come from somewhere - free hydrogen just doesn't occur naturally, so it's more of an intermediate stage between some other form of energy and something you can haul around. By the time you factor in the efficiency of electrolysis (the only feasible process for mass hydrogen production that I'm aware of - anybody more knowledgable about this than me?), it's about the same energy density as gasoline, and you've wasted 30% of your input energy. Same to worse with most other alternative chemical fuels.
Solar? Forget it - even if photovoltaics were 100% efficient (which isn't and won't ever be possible), that's still only 1kW/m^2 average in the US. (Practical terrestrial grade cells are currently 15-17% efficient and about $9US/W. By the time you get them encapsulated and strung together, they're about $25-30US/W. Prohibitively expensive, big, and most of all, fragile. Imagine instead of just replacing a panel and doing some painting next time you're in a wreck, replacing a $50,000 array as well, because it has hairline cracks all through it... ouch...)
It's fairly obvious that current batteries are not practical for any long-range vehicle, and especially not one designed for extended (multiple refuel/rechargings per day) as batteries just don't recharge that fast. Piling in enough batteries to give a common sedan adequate range for most Americans out here in the West (the Eastern megalopolis is another issue, with the close proximity of everything). On average, I put on about 1k miles/week, and that's more than any currently-available system other than ICE/gasoline can practically handle.
So, why not build an ultralight car and just reduce the amount fuel it needs for propulsion? Twofold: 1) ultra-light probably means moving away from steel, which significantly raises the cost and 2) ulta-light probably can't take much punishment without being irreparably damaged or injuring the occupants.
While I don't dispute that gasoline is not the final solution, for right now it's the best we've got. Certainly it can be made less-poluting (better engines, better emissions equipment, oxygenated fuels), and I'd be willing to pay a bit more for that. And I'd like to see more time and research thrown at improving alternative fuel sources [Especially my dream fusion tokamak I asked for earlier...;)] Just right now I don't think it's practical to switch most countries over. The Eastern US and most of Western Europe I think are notable exceptions, though - because of the small distances involved in normal travel, vehicles with less range and longer recharge/refuel cycles are practical. Anybody else from got any thoughts on this?
Quickie SUV Anti-Rant Just because all you anti-big-truck fanatics are bitching in here: Let it be said I do drive a large truck (1993 4WD K-Blazer) and the only way you'll get it away from me is to pry it from my cold dead hands. I don't care what gas costs, that's really irrelevant to me. The fact that I'm not cramped into a little itty bitty car shell is the only way I can possibly stand doing 1200 mile days (IL to CO). I've always driven large trucks (up to and including large tractor/trailer rigs, I used to hold a CDL, but no longer have a use for it...), unlike most of the yuppies buying SUVs these days, I actually use mine for hauling and towing and back-roading in places that would kill cars dead. Most importantly, I also realize that I'm driving a 3-ton kinetic weapon, and if I make mistakes at speed and I hit another vehicle, most likely someone is going to die. Just having moved to Colorado for work, I'm surrounded by people who don't understand that a K-Blazer/Yukon/Tahoe/Suburban is a full-sized truck and drives like such, not a passenger car. They also don't realize the implications of making a mistake while driving such a thing. When handled and maintained correctly, they're a beautiful pieces of engineering that can go places that eat little cars for lunch. The problem isn't the vehicle - it's the stupid fscking people who don't fscking know how to drive such a creature properly and responsibly. (Sorry to check my fs twice in one sentence...) They make the rest of us look bad. Did I mention that my SUV used to run Linux (for a vehicle telemetry project)? :) End of SUV-hater-hating rant.