If you want a world where no-one is poor, or hungry, or suffers... It's impossible.
However, a world where poverty and hunger are rare is entirely possible. In fact, we could do it right now, today.
... Though not through the means that most of those who loudly claim it as their goal, would think... or approve of.
The way to get there is by moving towards a post scarcity economy. Not to redistribute material wealth, but to make everyone so materially wealthy, that there would be no point.
And that IS possible.
We already live in a world where we can produce enough food, cheaply enough, for no-one to ever be hungry again.
... but most of it is wasted (seriously, most... between 60% and 80% of all food grown in advanced economies is wasted), because of government corruption, stupidity, or outright tyranny (most famines are not the result of nature, but of government).
That wasted food isn't given away for free, because high energy costs make transportation too expensive, and because government makes laws and regulations against doing so,mor that make doing so too risky and expensive.
What about other goods?
The three biggest components of the cost of most material goods, are labor, energy, and legal and regulatory costs (including taxes).
Material costs for most goods are a small fraction in comparison, rarely exceeding 20% of the total cost of an item, and often comprising less than 5%.
...And even then, much of the costs of the raw materials are themselves, labor, energy, and legal and regulatory costs (including taxes).
It's not greedy evil profit that makes and keeps things expensive... It's the cost of energy, the cost of labor, and the costs imposed by government and the legal system.
Right now, today, we could dramatically reduce the wasteful overheads imposed by government and the legal system, without hurting safety a single bit.
We could dramatically reduce taxes, and regulations, keeping only those that demonstrably improve safety to a reasonable degree for the costs they impose.
We could make industries far more competitive, by reducing barriers to entry created by governments.
We could dramatically increase employment at the same time, and wages, as businesses competed for workers, who had more money to pay those businesses.
We know all of these things work, because they always have, and always do. When we get out of the way.
But the single biggest thing we could do, to dramatically increase the material wealth of the world, and to dramatically improve the human condition...
Cheap energy.
If we could deliver energy so cheap that we didn't have to bother metering it, then we could achieve a near post scarcity economy, almost immediately.
With enough energy, cheap enough, we can achieve matter synthesis for many substances relatively easily.
With enough energy, cheap enough, aluminum, copper, gold, silver, silicon, and many other currently expensive materials, become dirt cheap.
With enough energy, cheap enough, plastics and anything derived from petrochemicals or other hyrdocarbons, become so cheap as to be effectively zero cost.
With enough energy, cheap enough, we have effectively unlimited clean fresh water, and can easily clean the air.
With enough energy, cheap enough, we can synthesize whatever fuels we want... Or mostly not bother, because the only thing we'd need chemical fuels for anymore was highly efficient long distance bulk cargo transportation, and air travel.
If you're really worried about carbon output from the human race... How about eliminating more than 80% of it, permanently?
With enough energy, cheap enough, we don't have to worry about efficiency of transport and storage technologies... though we will still develop them so that we can replace chemical fuels in air travel and bulk cargo transport, and to improve range and grid independence.
With enough energy, cheap enough, the cost of manufactured goods falls anywhere from 20% to more than 80%... and employment booms, and economies boom, and everyone gets much wealthier... rich and poor alike.
With enough energy, cheap enough, about 90% of the world's troublespots, stop being troublespots, and most of them we wouldn't have to care about.
If you want to "end war" it's impossible, but if you want to make it much rarer, smaller scale, and less destructive... cheap energy is the best way to do that.
Guess what?
We could do most of this, in less than 20 years, simply by deploying a widely distributed localized grid, of thorium reactors (technically, encapsulated pebble bed, low temperature and pressure gas coolant, thorium reactors... and/or natural convection, low pressure thorium salt reactors).
They have functionally negligible waste, their fuel cost per gigawatt is negligible, and they are many times safer than current coal and natural gas power. They are incredibly cheap to build and operate, they can't be weaponized, they can't have a meltdown or other destructive catastrophic failure... if you don't believe me, don't believe the propaganda, go an do the research yourself.
If we decided to get out of the way and get behind this entirely, we would have power at a cost of pennies per megawatt hour... a tiny fraction of a percent of the cost today (in the U.S. average is something like $0.13 kwh right now with taxes and fees adding about 20% on top of that. Some states run several times that, and much of Europe several times that again).
This isn't some pie in the sky dream, it doesn't require 50 years of engineering work or basic science. There are no breakthroughs required... Unlike EVERY OTHER FORM OF POWER that could possibly be an alternative to today's power infrastructure. Solar, wind, geothermal, none of them could ever be more than a fraction of our needs at ridiculously high cost. Fusion requires both basic science breakthroughs and much more engineering work to be viable (if it ever is). It's all decades away at best, if ever.
We could do this today.
Not 50 years from now... TODAY.
The 20 years isn't for more development, it's just how long it would take to complete the world wide economic transition to a cheap energy economy and infrastructure.
So, if what you really want, is to make a world where no-one goes hungry, and no-one is homeless... Then work for cheap and safe energy, and a huge reduction in government induced overhead. And it will happen.
Otherwise, what you really want, is a world where everyone is poorer, but where "evil profit" is eliminated, and "the rich" are punished, and everyone is economically "equal"; where the "right people are in charge", and will arrange the world the way you think is right, and punish the people you think are wrong.
Because that's all you're ever going to get, with more expensive energy, higher taxes, more government, and more redistribution.
Showing posts with label Environment. Show all posts
Showing posts with label Environment. Show all posts
Saturday, July 04, 2015
Tuesday, July 31, 2012
Whenever lefties say something stupid about "renewable energy"
... Which is of course fairly frequently, I tell them flat out "no, it won't work".
They then get this look on their faces like I'm just being an obstructionist ass and indignantly shout something like:
"Why not. These guys tell me we could have 20% of our power needs met by renewables RIGHT NOW, if we only had the political will/government subsidies/laws to force everyone to do it etc... etc... I bet you just hate the environment and love your SUV too much"
Well... it's a pickup truck, and yes, I do love it more than I love YOUR concept of what "the environment" is and/or should be (I LIVE in "the environment" you THINK you are talking about... I chose to move here specifically because of how it REALLY is... which has very little to do with how you THINK it is... but that's another story).
BUT...
No, that's not why it won't ever work.
"Ok... why not then, mr. pessimist".
Simple... Physics and Math.
...Not politics, not will, not lifestyle changes, not because we love our SUV's too much...
Just Physics and Math:
They then get this look on their faces like I'm just being an obstructionist ass and indignantly shout something like:
"Why not. These guys tell me we could have 20% of our power needs met by renewables RIGHT NOW, if we only had the political will/government subsidies/laws to force everyone to do it etc... etc... I bet you just hate the environment and love your SUV too much"
Well... it's a pickup truck, and yes, I do love it more than I love YOUR concept of what "the environment" is and/or should be (I LIVE in "the environment" you THINK you are talking about... I chose to move here specifically because of how it REALLY is... which has very little to do with how you THINK it is... but that's another story).
BUT...
No, that's not why it won't ever work.
"Ok... why not then, mr. pessimist".
Simple... Physics and Math.
...Not politics, not will, not lifestyle changes, not because we love our SUV's too much...
Just Physics and Math:
Monday, March 28, 2011
Wednesday, December 16, 2009
Monday, February 09, 2009
So, we're not all going to drown, or be killed by hurricanes?
This is the single best, and clearest, explanation of the Rationalist Position on wlobal warming I've Ever Seen
Key line: "So, why don't we ever talk about the suns contribution to global warming? ...Well, because we can't regulate it, tax it, or make it feel guilty for what it's doing".
Got it in one there friend.
There's no profit, political gain, or power to be grabbed from acknowledging the real causes, and real effects of whatever global warming there actually is. So, the interested parties simply ignore all that, shout down anyone who disagrees with them, and go about seizing as much power as they can, in a disorderly fashion.
From "What You Oughta Know", a website with videos explaining an assortment of general, and sometimes esoteric knowledge.
Oh and here are the links he mentioned in the video:
Oh and just for fun, here's the same sites take on "Liberals vs. Conservatives"... which is really a pretty solid explanation of the foundations of minarchist positions:
And a great take on the bailout:
Key line: "So, why don't we ever talk about the suns contribution to global warming? ...Well, because we can't regulate it, tax it, or make it feel guilty for what it's doing".
Got it in one there friend.
There's no profit, political gain, or power to be grabbed from acknowledging the real causes, and real effects of whatever global warming there actually is. So, the interested parties simply ignore all that, shout down anyone who disagrees with them, and go about seizing as much power as they can, in a disorderly fashion.
From "What You Oughta Know", a website with videos explaining an assortment of general, and sometimes esoteric knowledge.
Oh and here are the links he mentioned in the video:
Pacific Research Institute:
the documentary, more information
Reid A. Bryson - scroll down for ice cap article
Solar Activity: A dominant factor in climate dynamics - scroll down read sections in blue
BBC’s The Great Global Warming Swindle
Other possible causes for global warming
Oh and just for fun, here's the same sites take on "Liberals vs. Conservatives"... which is really a pretty solid explanation of the foundations of minarchist positions:
And a great take on the bailout:
Monday, March 19, 2007
There's an old saying...
...Actually two. The first is "if it's stupid and it works; it isn't stupid", the second is "if it seems too good to be true, it probably is".
What's amazing, is that sometimes, the first, can contradict the second in some pretty fun and interesting ways... but most of the time, it doesn't. Let's talk about one of those times.
So, the first saying...
One of the first examples given to illustrate the operating principles of small engines, is usually that of an air compressor. An internal combustion engine sucks in low pressure air, mixes it with fuel and a spark at something approaching a 14:1 ratio (with the fuel, not the spark), blows it up; and high pressure air comes out the other end... along with water vapor, carbon, carbon monoxide, carbon dioxide, nitrogen dioxide, ozone, partially burned and unburned fuel, and other nasty bi-products of the combustion of hydrocarbons.
Like almost all other reductions of complex machines into simple models, it's a stupid comparison; but it works (therefore, according to the maxim, it isn't stupid).
Now, what would happen if you took the fuel out? Well nothing because there would be no release of energy to make the pistons turn... so lets not simplify things that much. What if we take the fuel out AND we reversed the flow of high pressure air?
Well, hopefully something like this:
Actually, I was hoping for something a little less ugly and stupid looking but... as the saying says...
So the basic concept is this: Instead of high pressure exhaust coming out, we pump VERY high pressure air IN, which pushes the pistons (or turbines if you're so inclined, but I'm pretty sure they're using pistons in this application), turns the crank (and thus the transmission, and the wheels) and then exhausts as low pressure air (and a little water vapor and lubricating oil); basically an air compressor in reverse.
Here's the company line:
"Many respected engineers have been trying for years to bring a compressed air car to market, believing strongly that compressed air can power a viable "zero pollution" car. Now the first commercial compressed air car is on the verge of production and beginning to attract a lot of attention, and with a recently signed partnership with Tata, India’s largest automotive manufacturer, the prospects of very cost-effective mass production are now a distinct possibility. The MiniC.A.T is a simple, light urban car, with a tubular chassis that is glued not welded and a body of fibreglass."
...snip...
"Most importantly, it is incredibly cost-efficient to run – according to the designers, it costs less than one Euro per 100Km (about a tenth that of a petrol car). Its mileage is about double that of the most advanced electric car (200 to 300 km or 10 hours of driving), a factor which makes a perfect choice in cities where the 80% of motorists drive at less than 60Km. The car has a top speed of 68 mph.
Refilling the car will, once the market develops, take place at adapted petrol stations to administer compressed air. In two or three minutes, and at a cost of approximately 1.5 Euros, the car will be ready to go another 200-300 kilometres.
As a viable alternative, the car carries a small compressor which can be connected to the mains (220V or 380V) and refill the tank in 3-4 hours.
The temperature of the clean air expelled by the exhaust pipe is between 0 - 15 degrees below zero, which makes it suitable for use by the internal air conditioning system with no need for gases or loss of power."
How does it work?
"90m3 of compressed air is stored in fibre tanks. The expansion of this air pushes the pistons and creates movement. The atmospheric temperature is used to re-heat the engine and increase the road coverage. The air conditioning system makes use of the expelled cold air. Due to the absence of combustion and the fact there is no pollution, the oil change is only necessary every 31.000 miles.
At the moment, four models have been made: a car, a taxi (5 passengers), a Pick-Up truck and a van. The final selling price will be approximately 5.500 pounds."
Okay...
The geek in me is saying "oh cool", the engineer in me is saying "OK, how the hell are they gonna make THIS work?"
Not that a compressed air car can't work, obviously it can. The principle is very simple; the problem, as usual, is in the details. Specifically that little detail of efficiency.
Let's assume they pressurize the tanks to about 6000psi (about 400 bar, the highest conventional cascade compressor sets can go, the highest a reasonable pressure tank can store, and about twice a scuba tanks pressure).
If I'm reading correctly, they are taking 90 cubic meters of compressed air, and pushing a 1400lb or so vehicle, up to 68mph (110kph), with a 300km range.
I say 1400lb because thats about the minimum possible for the smallest model to hold two passengers, carry the essential propulsion gear, and electronics, and still have enough strength and structure not to collapse, even with advanced composites.
That car is going to need something like 20hp minimum, maybe 30hp (about 20kw); just to be able to get up to that speed (and more importantly, to be able to pull away from a stop sign on a hill).
Looking at a similarly specced vehicle, the French 2cv (or technically the 3cv model, which had 33hp -24kw-, and a 68mph top speed - that it took three minutes to accelerate to ) weighed about the same, and had about the same horsepower, and was dimensionally quite a bit smaller, so I think it's a reasonable estimate given newer more efficient materials end technology.
You really just can't move that much weight without pretty close to that much horsepower, and you really can't have a car that size with much less weight. Laws of physics being what they are and all.
So, to the second saying...
The rest of this will be in metric because those are the units easiest to work with here.
Given the range they've specified of 300km, and the power needed; we're looking at about 72KW/Hours of power; or 2,600,000,000 joules of total energy. Either 24watts for three hours, or 7 watts for 10 hours, the total energy is going to be about the same.
That has to come out of 90 cubic meters of high pressure air. At 400 bar, 90 cubic meters of compressed air, has about one and a half times that amount of potential energy.
Now remember, you can't get out more kinetic energy, than you have in potential energy. In fact, you can't even get as much out (that's called unity); because all systems are inefficient at converting potential energy to kinetic energy, to some degree.
So, it's good that there's 1.5 times as much potential energy as the engine needs right?
Here's the problem though, there is no way in hell that the thing is even 50% energy efficient. In fact, it would be an engineering miracle if they got out much more than 25% of what they put in.
Not only that; but you've actually only got about 2/3 of that energy as usable, because even at 100% efficiency you're going to need to flow about 200bar of pressure to get that 24kw (and given the volume of air available and 3 hour range).
Ok, so once again, 90 cubic meters; only presuming a minimum 200bar operating pressure, and 25% efficiency: You'd need to pressurize the tank to at least 1200 bar, or almost 20,000 psi. That's 4 times the highest pressure scuba tank (some HPBA systems are at 300 bar) or six times a standard tank.
Now these are all just really rough numbers, and who knows, maybe there IS an engineering miracle here. Also, its entirely possible they ARE pressurizing the thing to 1200bar; there are plenty of industrial applications that use pressures that high. In fact, there are common industrial applications (and equipment) for low density fluids (very few substances remain a gas at such high pressures, and nitrogen which air is mostly made up of, isn't one of them) at up to 150,000 PSI. It's just that such high pressures are not easy (and not cheap) to deal with, to store, to distribute, and to create in the first place.
Speaking thereof, the energy required to pump the high pressure air is going to be tremendous; because typical air compressor systems are terrifically inefficient; never mind the transportation and distribution infrastructure, which at least double that energy cost for production.
So yeah, your three minute fill up may have no direct emissions; but you're using probably 1440 KWh of energy total (inc. manufacture and distribution of the high pressure gas). At bout 8 cents per KWh (American national average. In India, where the car will be made, the national average is about 6 cents per Kwh) that would be $115.
$115 ??? but the article says about $2.80 (1.50 euro, at about $1.87 per euro at the moment). At $0.05 per Kwh in India, they're saying that they are using 56kwh of power total.
Honestly, I don't see how that's possible. For one thing, there's no way you could get 700kg to 110kph on 18.5kw; even assuming 100% efficiency (which is impossible).
But wait, theres more: they say that the car will come with a compressor that will reach a full charge in 3 to 4 hours, off a 240v Indian standard socket (240v at 15amp, for 3.6Kwh per hour, 4 hours, total energy about 15Kwh). Once again, assuming 100% efficiency, thats only 5Kw of power to move that 700kg, 110Kph.
That is absolutely impossible. Even at 500kg, thats not possible... hell it's maybe just barely possible at 250kg, and thats lighter than any but the lightest motorcycles and riders.
Hell, it's not even possible for a small compressor operating off standard mains current to achieve anything close to the operating pressures required.
The best portable commercial systems can flow about 15cfm at 6000psi (about 4 hours to fill the cars tank to 6000psi), and require either a 40amp 240v circuit; or a 25hp diesel motor. They are also about the size of a desk, weigh several hundred pounds, and start at about $30,000.
Let's just go over this one more time.
1. It is impossible to get more energy out, than you put in (you can't reach over unity).
2. In fact, its impossible to get even as much energy out, as you put in (you can't reach unity).
3. The best possible energy efficiency for systems of this type might be 25%, or assuming a technological miracle let's say 50%.
4. Even at 100% efficiency (which is impossible), 20-24kw (28-33hp) would be required for the vehicle to reach 110kph.
5. Even at 100% efficiency (which is impossible) 20-24kw for three hours (the specified range) would require 60-72Kwh (or 5-7kw for 10 hours, requiring pretty much the s
6. Even at 100% efficiency for both the engine, and the compressor system, the MOST possible energy that could be stored by the compressor system specified (230v at 15amp) in 4 hours would be 15Kwh; or 5Kw per hour for the three hour range specified.
7. It is impossible that such a vehicle would weigh less than 500kg. In fact it is nearly impossible it would weigh less than 700kg.
9. 5Kw will not move even 500kg to 110kph, never mind 700kg. In fact, that power would only move such a weight to about 20kph.
So, what they are describing is flat out impossible. Either the company promoting this wonder care are outright lying (possible, but seems unlikely), shading the truth to a ridiculous degree (highly likely, but still not enough), the reporter is a credulous idiot (almost certain, but also not enough in and of itself), or all three.
Personally, I'm thinking all three.
UPDATE:
Reader Smitty gives us a link to the actual designer of the vehicles in question.
Thank you very much sir, I appreciate that. I must have been stupid and not seen that among all the clutter on the article page.; and believe me I was looking.
At any rate, the first thing to note is, the vehicle is not in fact exclusively powered by compressed air. Apparently the motor is a hybrid diesel electric, with a low speed circuit powered by compressed air. This low speed circuit can be boosted by the electric portion of the drivetrain.
The low speed circuit operates at up to about 36kph generally. Above that speed the diesel circuit kicks in, up to about 60kph, when the compressed air circuit kicks out and the diesel goes it on it's own until top speed of 110kph. In addition to primary power, the diesel circuit is used to recharge the compressed air tanks when the pressure gets too low, or there is extra capacity the engine doesn't need for propulsion.
The waste heat from the diesel circuit is also used to maintain operating temperature of the engine, and reheat the super cooled exhaust air (very high pressure fluid, being released into very low pressure, means vapor phase change refrigeration whether you want it to or not). It is unclear what the range is when traveling exclusively on the air circuit.
Honestly, that's great. It's a good idea for using the waste energy of a vehicle to do something useful. Of course, the marketing page for the vehicles, and the article, make no mention of any of this. They refer to the car exclusively as a zero emissions vehicle, say it produces zero pollution, and explicitly say it doesn't burn any fuel, therefore never requires an oil change.
Lesse, shading the truth just a bit hard, a little bit of outright lying, and a credulous reporter?
Yeah I think so.
Now, as to my engineering assumptions; I haven't been able to find specific details as to how much HP the engine produces while on compressed air circuit vs diesel circuit, but this page does give some basic tech specs (in spanish):
Empty Weight: 550kg
Horsepower: 25bhp
Range without refueling in city driving: 150km
Stick in two small people and you get, 700kg or so, which is right in line with what I was saying, and with 25hp they are getting their top speed of 110kph... but their range is half what the article said, and that's at their projected "city speeds" of 36kph.
That's OK, seriously it's a significant engineering achievement. That's a VERY light, comparatively roomy city car that's incredibly efficient. It uses every possible means of increasing that efficiency, and apparently does a damn good job of it.
...just don't advertise it as an absolute zero emissions, pollution free wonder car that runs on compressed air, because it isn't.
What it is, is a more efficient and better conceived hybrid... and for once a hybrid that isn't a net environmental detriment (look it up, the electrical systems in hybrids cost more energy to produce than they save, and they are terribly harsh on the environment to dispose of).
That's great; more power to them, and I hope the car is a huge success.
Just one thing though: please stop trying to convince us you can do the impossible. We engineer types really don't like it when you do that; it makes us all twitchy.
What's amazing, is that sometimes, the first, can contradict the second in some pretty fun and interesting ways... but most of the time, it doesn't. Let's talk about one of those times.
So, the first saying...
One of the first examples given to illustrate the operating principles of small engines, is usually that of an air compressor. An internal combustion engine sucks in low pressure air, mixes it with fuel and a spark at something approaching a 14:1 ratio (with the fuel, not the spark), blows it up; and high pressure air comes out the other end... along with water vapor, carbon, carbon monoxide, carbon dioxide, nitrogen dioxide, ozone, partially burned and unburned fuel, and other nasty bi-products of the combustion of hydrocarbons.
Like almost all other reductions of complex machines into simple models, it's a stupid comparison; but it works (therefore, according to the maxim, it isn't stupid).
Now, what would happen if you took the fuel out? Well nothing because there would be no release of energy to make the pistons turn... so lets not simplify things that much. What if we take the fuel out AND we reversed the flow of high pressure air?
Well, hopefully something like this:
Actually, I was hoping for something a little less ugly and stupid looking but... as the saying says...
So the basic concept is this: Instead of high pressure exhaust coming out, we pump VERY high pressure air IN, which pushes the pistons (or turbines if you're so inclined, but I'm pretty sure they're using pistons in this application), turns the crank (and thus the transmission, and the wheels) and then exhausts as low pressure air (and a little water vapor and lubricating oil); basically an air compressor in reverse.
Here's the company line:
"Many respected engineers have been trying for years to bring a compressed air car to market, believing strongly that compressed air can power a viable "zero pollution" car. Now the first commercial compressed air car is on the verge of production and beginning to attract a lot of attention, and with a recently signed partnership with Tata, India’s largest automotive manufacturer, the prospects of very cost-effective mass production are now a distinct possibility. The MiniC.A.T is a simple, light urban car, with a tubular chassis that is glued not welded and a body of fibreglass."
...snip...
"Most importantly, it is incredibly cost-efficient to run – according to the designers, it costs less than one Euro per 100Km (about a tenth that of a petrol car). Its mileage is about double that of the most advanced electric car (200 to 300 km or 10 hours of driving), a factor which makes a perfect choice in cities where the 80% of motorists drive at less than 60Km. The car has a top speed of 68 mph.
Refilling the car will, once the market develops, take place at adapted petrol stations to administer compressed air. In two or three minutes, and at a cost of approximately 1.5 Euros, the car will be ready to go another 200-300 kilometres.
As a viable alternative, the car carries a small compressor which can be connected to the mains (220V or 380V) and refill the tank in 3-4 hours.
The temperature of the clean air expelled by the exhaust pipe is between 0 - 15 degrees below zero, which makes it suitable for use by the internal air conditioning system with no need for gases or loss of power."
How does it work?
"90m3 of compressed air is stored in fibre tanks. The expansion of this air pushes the pistons and creates movement. The atmospheric temperature is used to re-heat the engine and increase the road coverage. The air conditioning system makes use of the expelled cold air. Due to the absence of combustion and the fact there is no pollution, the oil change is only necessary every 31.000 miles.
At the moment, four models have been made: a car, a taxi (5 passengers), a Pick-Up truck and a van. The final selling price will be approximately 5.500 pounds."
Okay...
The geek in me is saying "oh cool", the engineer in me is saying "OK, how the hell are they gonna make THIS work?"
Not that a compressed air car can't work, obviously it can. The principle is very simple; the problem, as usual, is in the details. Specifically that little detail of efficiency.
Let's assume they pressurize the tanks to about 6000psi (about 400 bar, the highest conventional cascade compressor sets can go, the highest a reasonable pressure tank can store, and about twice a scuba tanks pressure).
If I'm reading correctly, they are taking 90 cubic meters of compressed air, and pushing a 1400lb or so vehicle, up to 68mph (110kph), with a 300km range.
I say 1400lb because thats about the minimum possible for the smallest model to hold two passengers, carry the essential propulsion gear, and electronics, and still have enough strength and structure not to collapse, even with advanced composites.
That car is going to need something like 20hp minimum, maybe 30hp (about 20kw); just to be able to get up to that speed (and more importantly, to be able to pull away from a stop sign on a hill).
Looking at a similarly specced vehicle, the French 2cv (or technically the 3cv model, which had 33hp -24kw-, and a 68mph top speed - that it took three minutes to accelerate to ) weighed about the same, and had about the same horsepower, and was dimensionally quite a bit smaller, so I think it's a reasonable estimate given newer more efficient materials end technology.
You really just can't move that much weight without pretty close to that much horsepower, and you really can't have a car that size with much less weight. Laws of physics being what they are and all.
So, to the second saying...
The rest of this will be in metric because those are the units easiest to work with here.
Given the range they've specified of 300km, and the power needed; we're looking at about 72KW/Hours of power; or 2,600,000,000 joules of total energy. Either 24watts for three hours, or 7 watts for 10 hours, the total energy is going to be about the same.
That has to come out of 90 cubic meters of high pressure air. At 400 bar, 90 cubic meters of compressed air, has about one and a half times that amount of potential energy.
Now remember, you can't get out more kinetic energy, than you have in potential energy. In fact, you can't even get as much out (that's called unity); because all systems are inefficient at converting potential energy to kinetic energy, to some degree.
So, it's good that there's 1.5 times as much potential energy as the engine needs right?
Here's the problem though, there is no way in hell that the thing is even 50% energy efficient. In fact, it would be an engineering miracle if they got out much more than 25% of what they put in.
Not only that; but you've actually only got about 2/3 of that energy as usable, because even at 100% efficiency you're going to need to flow about 200bar of pressure to get that 24kw (and given the volume of air available and 3 hour range).
Ok, so once again, 90 cubic meters; only presuming a minimum 200bar operating pressure, and 25% efficiency: You'd need to pressurize the tank to at least 1200 bar, or almost 20,000 psi. That's 4 times the highest pressure scuba tank (some HPBA systems are at 300 bar) or six times a standard tank.
Now these are all just really rough numbers, and who knows, maybe there IS an engineering miracle here. Also, its entirely possible they ARE pressurizing the thing to 1200bar; there are plenty of industrial applications that use pressures that high. In fact, there are common industrial applications (and equipment) for low density fluids (very few substances remain a gas at such high pressures, and nitrogen which air is mostly made up of, isn't one of them) at up to 150,000 PSI. It's just that such high pressures are not easy (and not cheap) to deal with, to store, to distribute, and to create in the first place.
Speaking thereof, the energy required to pump the high pressure air is going to be tremendous; because typical air compressor systems are terrifically inefficient; never mind the transportation and distribution infrastructure, which at least double that energy cost for production.
So yeah, your three minute fill up may have no direct emissions; but you're using probably 1440 KWh of energy total (inc. manufacture and distribution of the high pressure gas). At bout 8 cents per KWh (American national average. In India, where the car will be made, the national average is about 6 cents per Kwh) that would be $115.
$115 ??? but the article says about $2.80 (1.50 euro, at about $1.87 per euro at the moment). At $0.05 per Kwh in India, they're saying that they are using 56kwh of power total.
Honestly, I don't see how that's possible. For one thing, there's no way you could get 700kg to 110kph on 18.5kw; even assuming 100% efficiency (which is impossible).
But wait, theres more: they say that the car will come with a compressor that will reach a full charge in 3 to 4 hours, off a 240v Indian standard socket (240v at 15amp, for 3.6Kwh per hour, 4 hours, total energy about 15Kwh). Once again, assuming 100% efficiency, thats only 5Kw of power to move that 700kg, 110Kph.
That is absolutely impossible. Even at 500kg, thats not possible... hell it's maybe just barely possible at 250kg, and thats lighter than any but the lightest motorcycles and riders.
Hell, it's not even possible for a small compressor operating off standard mains current to achieve anything close to the operating pressures required.
The best portable commercial systems can flow about 15cfm at 6000psi (about 4 hours to fill the cars tank to 6000psi), and require either a 40amp 240v circuit; or a 25hp diesel motor. They are also about the size of a desk, weigh several hundred pounds, and start at about $30,000.
Let's just go over this one more time.
1. It is impossible to get more energy out, than you put in (you can't reach over unity).
2. In fact, its impossible to get even as much energy out, as you put in (you can't reach unity).
3. The best possible energy efficiency for systems of this type might be 25%, or assuming a technological miracle let's say 50%.
4. Even at 100% efficiency (which is impossible), 20-24kw (28-33hp) would be required for the vehicle to reach 110kph.
5. Even at 100% efficiency (which is impossible) 20-24kw for three hours (the specified range) would require 60-72Kwh (or 5-7kw for 10 hours, requiring pretty much the s
6. Even at 100% efficiency for both the engine, and the compressor system, the MOST possible energy that could be stored by the compressor system specified (230v at 15amp) in 4 hours would be 15Kwh; or 5Kw per hour for the three hour range specified.
7. It is impossible that such a vehicle would weigh less than 500kg. In fact it is nearly impossible it would weigh less than 700kg.
9. 5Kw will not move even 500kg to 110kph, never mind 700kg. In fact, that power would only move such a weight to about 20kph.
So, what they are describing is flat out impossible. Either the company promoting this wonder care are outright lying (possible, but seems unlikely), shading the truth to a ridiculous degree (highly likely, but still not enough), the reporter is a credulous idiot (almost certain, but also not enough in and of itself), or all three.
Personally, I'm thinking all three.
UPDATE:
Reader Smitty gives us a link to the actual designer of the vehicles in question.
Thank you very much sir, I appreciate that. I must have been stupid and not seen that among all the clutter on the article page.; and believe me I was looking.
At any rate, the first thing to note is, the vehicle is not in fact exclusively powered by compressed air. Apparently the motor is a hybrid diesel electric, with a low speed circuit powered by compressed air. This low speed circuit can be boosted by the electric portion of the drivetrain.
The low speed circuit operates at up to about 36kph generally. Above that speed the diesel circuit kicks in, up to about 60kph, when the compressed air circuit kicks out and the diesel goes it on it's own until top speed of 110kph. In addition to primary power, the diesel circuit is used to recharge the compressed air tanks when the pressure gets too low, or there is extra capacity the engine doesn't need for propulsion.
The waste heat from the diesel circuit is also used to maintain operating temperature of the engine, and reheat the super cooled exhaust air (very high pressure fluid, being released into very low pressure, means vapor phase change refrigeration whether you want it to or not). It is unclear what the range is when traveling exclusively on the air circuit.
Honestly, that's great. It's a good idea for using the waste energy of a vehicle to do something useful. Of course, the marketing page for the vehicles, and the article, make no mention of any of this. They refer to the car exclusively as a zero emissions vehicle, say it produces zero pollution, and explicitly say it doesn't burn any fuel, therefore never requires an oil change.
Lesse, shading the truth just a bit hard, a little bit of outright lying, and a credulous reporter?
Yeah I think so.
Now, as to my engineering assumptions; I haven't been able to find specific details as to how much HP the engine produces while on compressed air circuit vs diesel circuit, but this page does give some basic tech specs (in spanish):
Empty Weight: 550kg
Horsepower: 25bhp
Range without refueling in city driving: 150km
Stick in two small people and you get, 700kg or so, which is right in line with what I was saying, and with 25hp they are getting their top speed of 110kph... but their range is half what the article said, and that's at their projected "city speeds" of 36kph.
That's OK, seriously it's a significant engineering achievement. That's a VERY light, comparatively roomy city car that's incredibly efficient. It uses every possible means of increasing that efficiency, and apparently does a damn good job of it.
...just don't advertise it as an absolute zero emissions, pollution free wonder car that runs on compressed air, because it isn't.
What it is, is a more efficient and better conceived hybrid... and for once a hybrid that isn't a net environmental detriment (look it up, the electrical systems in hybrids cost more energy to produce than they save, and they are terribly harsh on the environment to dispose of).
That's great; more power to them, and I hope the car is a huge success.
Just one thing though: please stop trying to convince us you can do the impossible. We engineer types really don't like it when you do that; it makes us all twitchy.
Thursday, February 24, 2005
Fusion, will it ever happen
Someone brought up some alternative energy articles at the nation of riflemen forum, and it broguht me over to SDB's archive at uss clueless which got me to thinking again about fusion, and more specifically how terrestrial fusion isnt going to be a viable solution for a hell of a long itme if ever.
Anyway I wrote this a while back, and I'm updating it here because it's something I want to talk about with "my audience".
I said above, IF fusion is ever going to be viable, meaning that I think there are some reasons that's going to be tough. There's a few BIG issues here on the fusion topic:
More in the extended entry...
1. Touch off point/break even point.
This is the amount of energy and reactive mass (which are ultimately the same thing but that's another topic) required to produce a self sustaining reaction that outputs more energy then it sucks in. Basically how do we get the damned thing primed. Thus far we have been mostly unsuccessful in reaching the breakeven point. The few times it was MAYBE achieved it didn't last long and it was uncontrolled which brings up point two.
2. Controllability
We have no idea how to control a self sustaining fusion reaction, or if it is even possible to control. the best ideas so far involve massive torroidal field generators which control plasma flow. Small problem, what happens when the energy of the fusion reaction vastly exceeds the energy of the fields controlling that reaction? Oh and assuming we contain the reaction how do we throttle it without dropping below the touchoff point? Because the natural tendency of the reaction is to grow til the point where it is either fuel exhausted, too unstable to continue, or otherwise self limiting for various reasons.
According to everything we know (which I'll admit isn't a hell of a lot) these self limiting points are far greater than we can currently handle, or even have any concept of how we might handle them in the future.
If you don't believe me think about this. The largest fusion reactions we as humans are able to produce are in the gigaton range, the largest we can control are in the several molecule range (yes I know there's no basis for dimensional analysis here because the units are incompatible). These gigaton reactions are not inherently self limiting in the pure sense, though because of the methods used to initiate the fusion as well as the materials used in the devices and produced during the reaction (primarily tritium and helium which tend to absorb neutron flux) they actually are.
5. Neutron flux and hard alpha
Guess what folks, fusion reactions aren't 'clean' in that they do produce massive amounts of radiation that is harmful to carbon based life forms.Primarily these are in the form of neutron flux and alpha particle radiation.
Neutron flux is one of the primary sources of background radiation in the universe, all that nice radio noise, microwave radiation through space etc... But that's at light-years distance. At anything less than half an AU it starts getting more dangerous.
Hard alpha is the emission of high energy alpha particles. These nasty little buggers can at most cause the disintegration of your molecular structure (not atomic structure, molecular structure) and at the least cause genetic defects in a few cells. It's kind of like shooting marbles with your molecules, cept the relatively large molecules that make up much of our bodies are like 1" aggies and the little alpha particle is a BB some asshole just shot at them.
Yes, all of these are shieldable... the massive magnetic fields used to control the reaction, and the multiple layers of heavy shielding in the reactors... Though they wear out eventually, and if the magnetic fields were to collapse while the fusion reaction was going on...
.. That would be bad...
6. Fuel
So far the best success we've had with fusion comes from using hydrogen isotopes (some blend of tritium and deuterium) as the reactive mass. There's three problems with this. First, too little tritium and deuterium and the reaction starves out. Second, too much and the reaction absorbs itself because tritium and deuterium absorb the neutron flux that is generated by and sustains the reaction. Third, tritium is literally the most expensive commercially available substance on the planet. The amount of tritium in a high quality watch is far less than a milligram and yet costs in the neighbourhood of $10. By comparison a gram of .999 fine commodity gold is also about $10. Doing the math out that means tritium is at least a thousand times more expensive than gold.
Also we still haven't figured out a way to produce tritium on a large scale that doesn't involve nuclear fission reactors, and there is no way to store it for long periods of time because tritium has this irritating tendency to decay into other substances (deuterium, helium, and hydrogen).
7. Usability
Okay so lets assume we have a controlled self sustaining reaction that doesn't explode massively, instantaneously burn all matter on the planet, or emit so much hard alpha and neutron flux that we all dissolve into flaming little puddles of semi organic goo that glow like light sticks. Let us further assume that we have figured out how to fuel these reactions without bankrupting national economies.
Big assumptions those.
But let's say we do get past these issues, and I am sure that eventually we will if we research enough, what do we do with this fusion reaction?
The instinctive gut response is "use the energy". Ok, how? The most widespread way we as a species have come up with to put energy to use is electricity. Alright so we turn it into electricity.
How?
In the past three hundred years we have come up with precisely four ways for generating practical amounts of electricity (and a couple of interesting but impractical things too, but I won't get into them here): Interesting chemical reactions (this includes solar), smashing crystals, rubbing dissimilar materials together, and moving magnets near each other.
How is it that we will use the fusion reaction to do one of these things?
Okay how do we use the energy form a fission reaction to generate electricity? Well primarily we use the waste heat of the reaction to boil water, which then builds into high pressure vapor, which can be forced through a turbine.
That process will use what, a millionth of a percent of the energy released in the fusion reaction, a billionth? And of course the rest will be waste.
That much waste heat will be at minimum interesting to deal with.
Oh if only there were direct conversion. Of course then we wouldn't need fusion in the first place, or rather we wouldn't need terrestrial fusion, because all of our energy needs would be supplied by direct conversion of sunlight (instead of the now 10% or so maximum conversion efficiency we have with photovoltaic cells).
Anyway I wrote this a while back, and I'm updating it here because it's something I want to talk about with "my audience".
I said above, IF fusion is ever going to be viable, meaning that I think there are some reasons that's going to be tough. There's a few BIG issues here on the fusion topic:
More in the extended entry...
1. Touch off point/break even point.
This is the amount of energy and reactive mass (which are ultimately the same thing but that's another topic) required to produce a self sustaining reaction that outputs more energy then it sucks in. Basically how do we get the damned thing primed. Thus far we have been mostly unsuccessful in reaching the breakeven point. The few times it was MAYBE achieved it didn't last long and it was uncontrolled which brings up point two.
2. Controllability
We have no idea how to control a self sustaining fusion reaction, or if it is even possible to control. the best ideas so far involve massive torroidal field generators which control plasma flow. Small problem, what happens when the energy of the fusion reaction vastly exceeds the energy of the fields controlling that reaction? Oh and assuming we contain the reaction how do we throttle it without dropping below the touchoff point? Because the natural tendency of the reaction is to grow til the point where it is either fuel exhausted, too unstable to continue, or otherwise self limiting for various reasons.
According to everything we know (which I'll admit isn't a hell of a lot) these self limiting points are far greater than we can currently handle, or even have any concept of how we might handle them in the future.
If you don't believe me think about this. The largest fusion reactions we as humans are able to produce are in the gigaton range, the largest we can control are in the several molecule range (yes I know there's no basis for dimensional analysis here because the units are incompatible). These gigaton reactions are not inherently self limiting in the pure sense, though because of the methods used to initiate the fusion as well as the materials used in the devices and produced during the reaction (primarily tritium and helium which tend to absorb neutron flux) they actually are.
5. Neutron flux and hard alpha
Guess what folks, fusion reactions aren't 'clean' in that they do produce massive amounts of radiation that is harmful to carbon based life forms.Primarily these are in the form of neutron flux and alpha particle radiation.
Neutron flux is one of the primary sources of background radiation in the universe, all that nice radio noise, microwave radiation through space etc... But that's at light-years distance. At anything less than half an AU it starts getting more dangerous.
Hard alpha is the emission of high energy alpha particles. These nasty little buggers can at most cause the disintegration of your molecular structure (not atomic structure, molecular structure) and at the least cause genetic defects in a few cells. It's kind of like shooting marbles with your molecules, cept the relatively large molecules that make up much of our bodies are like 1" aggies and the little alpha particle is a BB some asshole just shot at them.
Yes, all of these are shieldable... the massive magnetic fields used to control the reaction, and the multiple layers of heavy shielding in the reactors... Though they wear out eventually, and if the magnetic fields were to collapse while the fusion reaction was going on...
.. That would be bad...
6. Fuel
So far the best success we've had with fusion comes from using hydrogen isotopes (some blend of tritium and deuterium) as the reactive mass. There's three problems with this. First, too little tritium and deuterium and the reaction starves out. Second, too much and the reaction absorbs itself because tritium and deuterium absorb the neutron flux that is generated by and sustains the reaction. Third, tritium is literally the most expensive commercially available substance on the planet. The amount of tritium in a high quality watch is far less than a milligram and yet costs in the neighbourhood of $10. By comparison a gram of .999 fine commodity gold is also about $10. Doing the math out that means tritium is at least a thousand times more expensive than gold.
Also we still haven't figured out a way to produce tritium on a large scale that doesn't involve nuclear fission reactors, and there is no way to store it for long periods of time because tritium has this irritating tendency to decay into other substances (deuterium, helium, and hydrogen).
7. Usability
Okay so lets assume we have a controlled self sustaining reaction that doesn't explode massively, instantaneously burn all matter on the planet, or emit so much hard alpha and neutron flux that we all dissolve into flaming little puddles of semi organic goo that glow like light sticks. Let us further assume that we have figured out how to fuel these reactions without bankrupting national economies.
Big assumptions those.
But let's say we do get past these issues, and I am sure that eventually we will if we research enough, what do we do with this fusion reaction?
The instinctive gut response is "use the energy". Ok, how? The most widespread way we as a species have come up with to put energy to use is electricity. Alright so we turn it into electricity.
How?
In the past three hundred years we have come up with precisely four ways for generating practical amounts of electricity (and a couple of interesting but impractical things too, but I won't get into them here): Interesting chemical reactions (this includes solar), smashing crystals, rubbing dissimilar materials together, and moving magnets near each other.
How is it that we will use the fusion reaction to do one of these things?
Okay how do we use the energy form a fission reaction to generate electricity? Well primarily we use the waste heat of the reaction to boil water, which then builds into high pressure vapor, which can be forced through a turbine.
That process will use what, a millionth of a percent of the energy released in the fusion reaction, a billionth? And of course the rest will be waste.
That much waste heat will be at minimum interesting to deal with.
Oh if only there were direct conversion. Of course then we wouldn't need fusion in the first place, or rather we wouldn't need terrestrial fusion, because all of our energy needs would be supplied by direct conversion of sunlight (instead of the now 10% or so maximum conversion efficiency we have with photovoltaic cells).
Wednesday, February 16, 2005
Withdrawal from the Kyoto treaty?
Today is the day that the harmful/useless feelgood transnational socialist piece of bullshit commonly known as the Kyoto Protocol Treaty goes into effect.
I've heard a couple people say things like "Evil BushHitler withdrew us from the Kyoto treaty", or "It's good that we withdrew from Kyoto" etc...
Actually there was no withdrawal, and it had nothing to do with Bush.
Although the president is empowered by the constitution to negotiate treaties, (and Clinton had a negotiating team in Kyoto), the presidents signature on a treaty means nothing unless it is ratified by the senate.
Under Clinton, the senate refused to even hold a ratification hearing for kyoto. I don't recall if there was ever a motion to vote it up or down, or if it was just a motion to consider the treaty, but either way it was voted down resoundingly (as in 80-20, but its 6:40 am and I'm too lazy to look it up).
Even if ALGORE had been elected we STILL wouldn't be in the kyoto economic death pact, because the senate said no.
This puts us in company along with at least 140 other countries BTW. In fact there are only 30 signatories, out of somewhare around 190 nations (I forget the official total, and as I said, it's too early for research). India and China didnt even bother showing up, and they are BY FAR the biggest polluters in the world (combined more than 10 times as much as the U.S., of course they also have about 10 times our population).Even better, only 2 of the 15 EU signatories have said they will fulfil their Kyoto requirements.
But of course it's all Bushes fault, because he hates the environment and thinks the faster we destroy the world, the faster Jesus will come.
Yeah, right, sure, go hug a tree ya idjits.
Tell ya what. If you have spent a month total in your life sleeping in the woods and mountains away from "civilization" eating that which you can find and/or Kill (and I have), THEN you are somewhat qualified to speak with me about the conservation of the environment. Do your research, read the science (not the agenda papers, real science), and then we can talk O.K.
If you fly in a private jet, or are driven anywhere in a limo, just shut the fuck up.
I've heard a couple people say things like "Evil BushHitler withdrew us from the Kyoto treaty", or "It's good that we withdrew from Kyoto" etc...
Actually there was no withdrawal, and it had nothing to do with Bush.
Although the president is empowered by the constitution to negotiate treaties, (and Clinton had a negotiating team in Kyoto), the presidents signature on a treaty means nothing unless it is ratified by the senate.
Under Clinton, the senate refused to even hold a ratification hearing for kyoto. I don't recall if there was ever a motion to vote it up or down, or if it was just a motion to consider the treaty, but either way it was voted down resoundingly (as in 80-20, but its 6:40 am and I'm too lazy to look it up).
Even if ALGORE had been elected we STILL wouldn't be in the kyoto economic death pact, because the senate said no.
This puts us in company along with at least 140 other countries BTW. In fact there are only 30 signatories, out of somewhare around 190 nations (I forget the official total, and as I said, it's too early for research). India and China didnt even bother showing up, and they are BY FAR the biggest polluters in the world (combined more than 10 times as much as the U.S., of course they also have about 10 times our population).Even better, only 2 of the 15 EU signatories have said they will fulfil their Kyoto requirements.
But of course it's all Bushes fault, because he hates the environment and thinks the faster we destroy the world, the faster Jesus will come.
Yeah, right, sure, go hug a tree ya idjits.
Tell ya what. If you have spent a month total in your life sleeping in the woods and mountains away from "civilization" eating that which you can find and/or Kill (and I have), THEN you are somewhat qualified to speak with me about the conservation of the environment. Do your research, read the science (not the agenda papers, real science), and then we can talk O.K.
If you fly in a private jet, or are driven anywhere in a limo, just shut the fuck up.
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