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Alternate Energy Sources: Car fuel
bluefoxicy
Registered User regular
Registered User regular
I'm sure this'll turn into a debate somehow.
I keep hearing: "We need to find an alternative to oil in cars."
Okay? So what? Hydrogen? Anything that depends on the grid? Short-distance vehicles? Grid-attached mass transit (electric sub-rail)?
Lemme outline this for you:
OIL - Foreign, or we have political bullshit drilling in places. Oil prices are on the rise, and there's all this political bullshit about global warming.
ELECTRIC - Short distance. Grid-attached. Most grid power comes from coal or oil. Even if we switch to nuclear, solar, geothermal, whatever, it takes me as much as it takes to power my house to go back and forth to my job* each day-- in raw power, 100% efficiency, moving that mass over that distance in that time. 1 car is equivalent to 30 houses and people have 2-3 cars; the grid power is so high you'd need tons of nuke plants, plus the grid can't transfer power like that (it fails when everyone on my block cranks their AC up during the summer, 2-3 times a year, and then we don't have power for 6 hours).
HYDROGEN - Good luck. It's another form of oil though (insomuch as it's power used here to generate a chemical storage medium to generate work power at the usage point i.e. your engine; chemically it's not related). For electrolysis from water, better have your own on-site power generation; for catalyzing and catalyst-assisted hydrolysis, this has potential. Other methods like extracting it from biodiesel production or otherwise from plants may be feasible. Probably economically, environmentally, and simply feasibly our best bet.
LP GAS - Another fossil resource. A rebrand of oil, less refining needed if you can strike a volcanic vent that just pumps LP gas like crazy.
DIESEL - Oil. Better mileage, fuel density, better efficiency, burns cleaner with low-sulfur diesels. An improvement on the current situation, without leaving it.
BIODIESEL - Corn and soybean. A good solution, as diesel is a good solution. Unfortunately, it also turns our food crops (corn, soy, which are in everything i.e. HFCS and soy lechten as well as being feed crop and being ultimately valued as a farm land resource more than just a product) into fuel crop, which drastically affects the cost of food and is a net economic disaster.
ETHANOL - It's biodiesel in principle, but we produce a different chemical (alcohol rather than oil). Can run in gasoline engines.
Hydrogen can run in slightly modified gas engines, and can be produced from the same sources as biodiesel and ethanol. Ethanol can run in slightly modified engines, or mix down into standard gasoline engines.
Biodiesel and hydrogen are our best long-term solutions. Diesel as an oil resource would improve fuel economy due to denser fuel along with more efficient engine design. My nearest gas station supplies $1.999 regular unleaded gasoline and $2.099 diesel; transitioning to diesel first to get ready for a transition to biodiesel would be economically feasible (we can mix diesel and biodiesel in any quantity safely, I think). Biodiesel would require current-tech diesel engines with little to no modification (it may be heavy enough that you need to actively evaporate it when the engine's just starting); hydrogen would require current-tech gasoline engines with minor modification, as well as modification to the fuel system. It is likely quite possible to make a hydrogen/gasoline/ethanol car that can run any of these 3 fuels, but a mixture would likely be catastrophic.
Ethanol and hydrogen our best short term. Ethanol can mix with gasoline and burn in gasoline engines. Ethanol can burn in current-generation gas engines straight, but corrodes them; replacing aluminum parts would make 100% ethanol feasible. Modifying gasoline engines on the assembly line is barely even a design problem, just really a material science problem. Hydrogen needs a new fuel delivery system in the car (fuel tank, pump, rail, injectors, and control software all need to account for transferring hydrogen rather than ethanol or gasoline). Both need an exhaust with a condenser to turn water vapor into a liquid water flow.
Hybrids are bullshit. You make diesel or hydrogen, and add a hybrid design to it; you don't tout hybrids as a replacement for gas, because the car still runs on gas. A hybrid can have the gas engine ripped out and replaced with diesel, ethanol, or hydrogen engines (note that 3 of these 4 things are effectively the same) and still work, and still give any benefit on top of the improvements that the new engine brings.
*I have to drive a 3200 pound car 6.8 miles to work and 6.8 miles back. It takes roughly a half hour, actually less than that. There are hills involved both up and down both ways, but I accounted for flat ground because when you normalize it one path is the opposite advantage of the other.
I keep hearing: "We need to find an alternative to oil in cars."
Okay? So what? Hydrogen? Anything that depends on the grid? Short-distance vehicles? Grid-attached mass transit (electric sub-rail)?
Lemme outline this for you:
OIL - Foreign, or we have political bullshit drilling in places. Oil prices are on the rise, and there's all this political bullshit about global warming.
ELECTRIC - Short distance. Grid-attached. Most grid power comes from coal or oil. Even if we switch to nuclear, solar, geothermal, whatever, it takes me as much as it takes to power my house to go back and forth to my job* each day-- in raw power, 100% efficiency, moving that mass over that distance in that time. 1 car is equivalent to 30 houses and people have 2-3 cars; the grid power is so high you'd need tons of nuke plants, plus the grid can't transfer power like that (it fails when everyone on my block cranks their AC up during the summer, 2-3 times a year, and then we don't have power for 6 hours).
HYDROGEN - Good luck. It's another form of oil though (insomuch as it's power used here to generate a chemical storage medium to generate work power at the usage point i.e. your engine; chemically it's not related). For electrolysis from water, better have your own on-site power generation; for catalyzing and catalyst-assisted hydrolysis, this has potential. Other methods like extracting it from biodiesel production or otherwise from plants may be feasible. Probably economically, environmentally, and simply feasibly our best bet.
LP GAS - Another fossil resource. A rebrand of oil, less refining needed if you can strike a volcanic vent that just pumps LP gas like crazy.
DIESEL - Oil. Better mileage, fuel density, better efficiency, burns cleaner with low-sulfur diesels. An improvement on the current situation, without leaving it.
BIODIESEL - Corn and soybean. A good solution, as diesel is a good solution. Unfortunately, it also turns our food crops (corn, soy, which are in everything i.e. HFCS and soy lechten as well as being feed crop and being ultimately valued as a farm land resource more than just a product) into fuel crop, which drastically affects the cost of food and is a net economic disaster.
ETHANOL - It's biodiesel in principle, but we produce a different chemical (alcohol rather than oil). Can run in gasoline engines.
Hydrogen can run in slightly modified gas engines, and can be produced from the same sources as biodiesel and ethanol. Ethanol can run in slightly modified engines, or mix down into standard gasoline engines.
Biodiesel and hydrogen are our best long-term solutions. Diesel as an oil resource would improve fuel economy due to denser fuel along with more efficient engine design. My nearest gas station supplies $1.999 regular unleaded gasoline and $2.099 diesel; transitioning to diesel first to get ready for a transition to biodiesel would be economically feasible (we can mix diesel and biodiesel in any quantity safely, I think). Biodiesel would require current-tech diesel engines with little to no modification (it may be heavy enough that you need to actively evaporate it when the engine's just starting); hydrogen would require current-tech gasoline engines with minor modification, as well as modification to the fuel system. It is likely quite possible to make a hydrogen/gasoline/ethanol car that can run any of these 3 fuels, but a mixture would likely be catastrophic.
Ethanol and hydrogen our best short term. Ethanol can mix with gasoline and burn in gasoline engines. Ethanol can burn in current-generation gas engines straight, but corrodes them; replacing aluminum parts would make 100% ethanol feasible. Modifying gasoline engines on the assembly line is barely even a design problem, just really a material science problem. Hydrogen needs a new fuel delivery system in the car (fuel tank, pump, rail, injectors, and control software all need to account for transferring hydrogen rather than ethanol or gasoline). Both need an exhaust with a condenser to turn water vapor into a liquid water flow.
Hybrids are bullshit. You make diesel or hydrogen, and add a hybrid design to it; you don't tout hybrids as a replacement for gas, because the car still runs on gas. A hybrid can have the gas engine ripped out and replaced with diesel, ethanol, or hydrogen engines (note that 3 of these 4 things are effectively the same) and still work, and still give any benefit on top of the improvements that the new engine brings.
*I have to drive a 3200 pound car 6.8 miles to work and 6.8 miles back. It takes roughly a half hour, actually less than that. There are hills involved both up and down both ways, but I accounted for flat ground because when you normalize it one path is the opposite advantage of the other.
People call me Wood Man, 'cause I always got wood.
bluefoxicy on
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Diesel helps; we should make it easier to make and sell diesel cars in this country. Hydrogen and electric are more about carbon emissions than about preservation; it's much easier to reduce the emissions on one power plant than it is to reduce the emissions on ten thousand cars.
And if we start building more nuclear power plants, hydrogen and electric become way more desirable. They cease to be powered by fossil fuels.
Really, a big part of it needs to be conservation. We need to move closer to where we work and spend our leisure time, ride buses, bikes, or walk more, shop within walking distance, etc. There is no one, single panacea as far as alternative energy sources go.
I think it is clear that the grid is going to need extensive upgrading, whether or not we move to an electric car. A smart grid that can more efficiently regulate the flow of electricity is badly need.
Also, whatever we do, its going to be tough. Its going to require a massive reorientation to an entirely new energy source. Its going to be hard, but it has to be done.
Twitter
We can move them all to Florida. They'll fit right in.
Oh god don't do that to those poor poor people!
Twitter
To the Arizonians or the Floridians? I'm honestly not sure who you think would be hurt.
And using current technology, how big of a solar panel would someone need in a sunny area to power their electric car?
I think it's more than just a huge solar panel. You'd need to redesign the car itself to make things more efficient. That's why most hybrids only get 5-10 mpg more than their non-hybrid counterparts, while the dedicated hybrids (Prius, Insight) get almost double the fuel economy that other hybrids get.
Have you SEEN a prius?
If you ripped the electric motor out it might actually get 30-35mpg. The aerodynamics are amazing. Just look at the (ugly ass) thing.
If you're happy to go pure electric, then you can do fun stuff like this:
Refining biodiesel can be done chemically, biochemically, and enzymically. For the most part, you can let bacteria do a lot of the work without electricity/fire driven process.
If you could generate hydrogen chemically or catalytically (it's doable, or at least we can reduce the power costs and do it more efficiently), hydrogen fuel cars are a net win.
Bioreactors can do it as well: if I ingest fructose (Agave nectar is mostly fructose), flora in my intestines make both ethanol (hey, tequila!) and hydrogen gas. The hydrogen dissolves into my blood, and I exhale hydrogen (and fart it out). A big bioreactor (effectively a glorified septic tank) can produce both hydrogen and ethanol, or focus primarily on one or the other. A car could probably be made that can run on both these fuels safely, but not in combination....
Telling people to not use their cars as much is a path to failure. People don't want to do that. Deploying a better public transportation system would be a good thing though, especially if you could land stations right by (or inside) shopping malls and major hotels and have park-and-ride otherwise. It's not a short distance thing; if you have to drive half way across the city to work, it's easier to take the subway if trains arrive every 15 minutes (you skip rush-hour traffic).
Remember though, I live 6 miles from work and it takes as much energy as I need to run my house for a month to get to work and back if we go full electric.
I'm not seeing how removing the transmission, drive-shaft, or differentials are positives. Could you explain that?
Any type of hydrogen generation from water is snake oil and does nothing that a pure electrical system could not do better.
You're never going to make an energy profit seperating water into hydrogen and oxygen just so you can take the hydrogen and combine it back with oxygen again in a combustion reaction to produce water. Catalysts don't change that, they reduce wasted energy but there's no way to make an energeticly unfavorable reaction favorable, otherwise you'd have a perpetual motion machine.
You might as well just use whatever energy source you're splitting the water with to actually power the car.
The only possible benefit would be if you could somehow make hydrogen in a central location and transport it more cheaply than sending electricity through wires, or if by using hydrogen as a storage medium you could store more energy more efficiently than batteries.
Energy efficiency. Any time you have any mechanism between the source of energy (in the case of a car, the engine) and its output (the wheels), you will always have loss of power (e.g. friction). I'll have to do some digging, but I believe that transmissions* are only about 80% efficient at best. I haven't come across numbers for the drive-shaft or differentials, but I do not believe that they're anywhere close to 100% efficient either.
By comparison, if you look at the link, they're using hub motors which deliver power directly to the wheels without the need for transmission/gearing/differentials, thus eliminating the losses in those components.
So you end up doing more for the same amount of input power.
* I'm unaware if the figure I read was quoted for manual or automatic.
Nothing will happen without a systematic upgrade to how we power the grid. Right now that is mostly by coal, and if we don't change that we're not going to get anywhere.
Like Than said, it's a lot easier to clean up one power plant than ten thousand cars. It's also easier to switch the power source, say, if you figure out a cheaper method than coal - such as developing a new solar array in the Mojave.
One side-effect of retrofitting current vehicles to biodiesel is that it's really, really easy to make out of the leftovers from all the McDonalds fryers.
I believe the idea is that you simply run an electric motor on each wheel you want to provide power to. No transmission because you can get power from an electric motor at a much wider rpm-range than a gas engine. No drive shaft because the motor is local to the wheel. No differential because you can provide power to your drive wheels at whatever levels you want independantly.
Except you're using more input power, because you skipped the part about the whole point of overdrive. And you're making the car less safe because you're making it less stable while turning or driving on anything but perfect dry tarmac because you skipped the whole point of differentials. And honestly I'm not sure what the whole "getting rid of the drive-shaft" part is even about apart from snake-oil, because if I'm understanding their website right they're just doing the same thing the two-box design did fifty years ago.
And this is why PR is an immoral profession.
As for full electric cars, this was a somewhat mentioned benefit, but they are much simpler devices than internal combustion driven cars. There are a lot fewer parts. The cost of maintenance on electrics should be a good deal lower than on IC cars, which is good for the car driver but not so good for car companies that try to pick up margins on things like extended warranties and dealership mechanics.
The fundamental problem with electric cars is that battery technology is not good enough now for them to directly compete with gas cars in both price and quality and easy of use. If they can solve that (a very big if), then if you upgrade the grid electric cars should be very viable. Efficiency wise they should be a lot better than IC cars even if you burn fossil fuels to generate the electricity because it's a lot easier to improve the efficiency of a large, stationary power plant than it is to do so for hundreds or thousands of small engines with highly volatile energy demand.
This is the point. At this point hydrogen fuel cells can store more power than batteries at the same size.
I don't have the numbers on me to debate this particular point, I'm afraid.
You do realise that because each wheel has its own hub motor, and because each hub motor is independent, you can end up having each motor run at a different speed - thus acting like differentials?
You don't need a perpendicular drive shaft anymore, since each hub motor is quite literally inside the wheel itself. You have a motor, and the shaft of the motor is more or less physically directly connected to the wheel. (I say more or less, because if you go look at the datasheets for some of their hub motors, you end up bolting the wheel on, just like normal).
Of course you would never make an energy profit from electrolysis, but the process could be used in conjunction with renewable and nuclear energy. We need some form of portable energy storage and hydrogen fuel cells are our best bet right now.
Unless we have a breakthrough in capacitor technology.
You need numbers to determine whether spinning more times per minute requires more input energy than spinning less times per minute? It sounds like I should be afraid too...
What tells these motors what speeds to run at when you want them to run at different speeds? "A computer, duh!" is not a sufficient answer, because then I want to know what tells the computer what speeds to tell the motors to run at. Unless the programmer rides around in the car's undercarriage all the time, "the programmer!" isn't an answer either.
So yes, exactly what I said. Right. PR people should be shot.
Except maybe get power? Energy efficiency in an electric motor is inversely proportional to the cube of the size of the motor; energy efficiency relates directly to output working power. A small motor passing lots of current will overheat and melt, and needs more size to act as its own heat sink (lower resistive load). So a powerful electric motor must also be large, and energy inefficient.
Your statement is also overly broad. A catalyzing water-to-component-elements reaction, either partially catalyzing (makes separation an endothermic reaction that occurs at elevated temperatures, or room temperature with small amounts of electricity) or fully catalyzing (drop this metal into the water, and it explodes endothermically into hydrogen and oxygen gas with no input until it gets too cold), would pose an improvement over electrical systems because you could draw on ambient energy (you would cool the room in the process, drawing heat energy out of the surroundings).
See above. Catalysts can, in best case, lower the activation energy of the reaction to room temperature. On a physical level, a catalyst causes intra-molecular stress; the charge distribution on a catalyst causes parts of the molecules of the chemical to be reacted to move, with some atoms going in one direction and others going in another. This weakens the electrostatic bonds between them, either breaking them or allowing less activation energy to break them.
The energy source in a catalytic reaction would include ambient heat. As combustion produces heat, the separation of water and hydrogen must consume energy; any catalytic reaction (partial with electrical assistance or complete) would be endothermic, and cool its environment. You could thus enhance such a reaction by heating the medium; or produce it slowly.
Solar heat (solar water heat, water coupling to heat the very cold reaction tank) would harness solar power more efficiently than photovoltaic cells (actually, absolutely 100% efficient use of all heat actually transferred to the reaction medium; all loss is incurred in transit, so better insulated pipes and a more efficient heat exchanger would be the only thing you could do to improve efficiency of energy collection). This could be a method of collecting solar power more efficiently-- which means you can ship solar energy now.
There have been a few claims of sunlight + catalyst + water making hydrogen, but nothing I can find as substantial (MIT seems to have invented an electrolysis process that doesn't need a base environment and called it a catalyst... I suppose not needing free OH- floating around is a plus). Any such development would effectively be free energy (not quite, but you get the idea).
Photolysis of water could do this - finding a way to hook into photosynthetic processes, which do exactly this, seems technically possible, but likely to remain in the realm of science fiction in the near future. That said, if hydrogen and oxygen were captured directly, the efficiency seems likely to be significantly higher.
This is true right now, but it's hard to justify pouring billions into a process that has most of the disadvantages of electric as far as stress to the grid, requiring new plants, etc, but is also much less efficient, and could be completely obsoleted simply by the invention of a more energy-dense battery system.
+1 Insightful
You need to run for some political office. You have something called "Foresight."
Good lord. Do you understand how variable-torque drive systems operate? This is very similar.
By 'two-box' systems do you mean portal hubs? Because that isn't what he's talking about.
...
The second law of thermodynamics says hello.
I do actually, since while power (and subsequently energy) is directly proportional to the angular velocity, it is also proportional to the amount of torque required.
Unless you are asserting that torque is constant and that a vehicle does not accelerate/decelerate?
The same thing that tells a normal differential that two wheels should run at different speeds - torque feedback from the wheel. Or are you somehow implying that this form of feedback suddenly disappears in the absence of a differential?
You're not telling people anything, but believe me, they'll get the hint.
Absolutely incorrect, corn ethanol may or may not be energy negative (there's plenty far more compelling reasons not to turn our food supply into fuel), but that's beside the point. There's other forms of biodiesel in the world that are well energy positive and economical, not to mention several types of ethanol that we need more R&D with.
Cellulosic ethanol could turn out to be fucking amazing, and we already know sugar cane ethanol can offset a statistically significant portion of our usage if we combine it with conservation and hybrids.
Anyone saying biodiesel is a silver bullet is out of their minds, but it's just as incorrect to dismiss it out of hand.
Electric cars however are pretty spiffy. I got the chance to drive one years ago.
It would take some time, and some economy of scale to drive battery prices down, but its doable.
Except we don't, most cars just have open diffs. If they're 4/AWD they usually have two open diffs. Computers that tell the transmission when to shift aren't really relevant, the computer knows how fast the engine is spinning and how wide open the throttle is and can decide when to shift. The closest thing to what you're claiming is Mitsubishi's AYC which is prohibitively expensive and so only appears on their high-end sportscars.
Variable torque drives are neat but that's a handwave not an answer as they don't really do what I'm asking.
No, the two-box design is not a portal-hub, it's the reason why the majority of cars built in the last twenty years don't have a perpendicular driveshaft, though I see no reason why the two would have to be mutually exclusive either.
And if power is only being requested by one input then power requested for all four motors is the same even though we have more than one power-source.