Unless you happen to live close to the new coal-powered plant built to provide electricity for your ‘clean’ car. Why should the guy who chooses not to live in the city have to deal with your pollution?
I agree with most of what you’re saying, but some of your thought processes leave me a bit mindboggled. Pollution is pollution, no matter where you produce it, and sending it somewhere else is not a solution. I’m sure that the Swedish people took comfort during the 1970s and 80s in the knowledge that the pollution causing acid rain in their country was ‘distant’. In much the same way, all that nasty black shit in the air in Taiwan, emanating from coal-burning plants in mainland China, is equally part of the problem.
Now, what do I have to do to convince you that burning coal is not the answer to anything?
Dude, what is this vacuum-powered car? Vacuum energy is probably centuries away. Are you referring to the compressed-air powered vehicle?
Compressed air, like a battery, is simply a means of storing energy. The energy has to come from somewhere. No vehicle using stored ‘clean’ energy is clean until the energy comes from a clean source. The answer is not definitely yes.
Now, how efficient a storage medium is compressed air? According to the website for the li’l car featured, you need to run a 220v electric motor for 3-4 hours to drive the car 125-185 miles. So, how much fuel do you need to burn to run a 220v motor for 3-4 hours? And how much fuel would you need to burn to drive a low-power petrol-driven car for that distance?
How far could the same amount of electricity push a battery-driven car of the same power output?
These are the questions that should be answered before you start jumping up and down and saying that X is cleaner than Y.
And if coal is so clean, why did the UK give up using the stuff and convert a lot of it’s power stations to gas?
[quote=wikipedia]In 1990 just 1.09% of all gas consumed in the country was used in electricity generation. By 2004 the figure was 30.25%.
By 2004, coal use in power stations had fallen by 43.6% (50.5 million tonnes, representing 82.4% of all coal used in 2004) compared to 1980 levels, though up slightly from its low in 1999.[/quote]
Sorry, correction, air pressure powered car.
I thought that I had been clear in that electricity is not always from coal powered stations and may be obtained in more environmentally friendly measures, but in case of confusion I may clarify. An air powered car is more efficient than a fuel burning car because the electricity required to power a pump to compress the air does not have to come from burning fuel and so is more efficient and more friendly than an internal combustion engine. The problem is not with the design of the car, which is excellent. The problem is with the obtaining of electricity to compress the air. That having been said, it is not necessary to use electricity to power a compressor, a simple water or air powered compressor would also suffice.
Only if you refill it using a standard household compressor. Using an industrial compressor at a service station, it only takes 2-3 minutes.
So you and I both go to the service station. I have one of these compressed air cars, and you have a petrol car.
I need:
2-3 minutes of electricity for the air compressor
You need:
2-3 minutes of electricity for the petrol pump
So far, so good. Looks like we’re about even. However, in order to support the air compressor, I just need electricity. In order to support the petrol pump, you need:
Petrol which has to be extracted from oil by means of an entire industry
A truck to convey that petrol to the service station
Now let’s look at the pollution we both cause:
Compressed air car: Pollution caused by the power station supplying the electricity for the air compressor (could be oil, coal, nuclear, or hydro)
Petrol car: Environmental pollution caused by oil industry, local city air and noise pollution caused by petrol engine truck delivering petrol to the service station, local city air and noise pollution caused by your vehicle burning the petrol, pollution caused by the power station supplying the electricity for the petrol pump (could be oil, coal, nuclear or hydro)
It’s not difficult to see that the compressed air car comes out on top here, very easily. Your car requires two separate power sources to supply it, and only one of them can possibly be from a non-polluting industry. My car requires only one power source to supply it, and that power source can be from a non-polluting industry. Your car produces local air and noise pollution. My car doesn’t.
What the hell does -2-3 minutes of electricity from an air compressor mean? Last time I checked, electricity wasn’t measured by units of time.
Yet you fail to mention where the electricity used to power up the gas station’s compressor comes from OR the amount of electricity it uses and dispenses.
[quote=“Fortigurn”]
Now let’s look at the pollution we both cause:
Compressed air car: Pollution caused by the power station supplying the electricity for the air compressor (could be oil, coal, nuclear, or hydro)
Petrol car: Environmental pollution caused by oil industry, local city air and noise pollution caused by petrol engine truck delivering petrol to the service station, local city air and noise pollution caused by your vehicle burning the petrol, pollution caused by the power station supplying the electricity for the petrol pump (could be oil, coal, nuclear or hydro)
It’s not difficult to see that the compressed air car comes out on top here, very easily. Your car requires two separate power sources to supply it, and only one of them can possibly be from a non-polluting industry. My car requires only one power source to supply it, and that power source can be from a non-polluting industry. Your car produces local air and noise pollution. My car doesn’t.[/quote]
In fact its very difficult to conclude anything at all from what you’ve written, as you’ve not given any concrete figures for anything and you haven’t narrowed down the potential scenario’s to comparable examples.
Also you fail to mention that many modern petrol cars now emit more noise pollution from wind resistance than they do from the sounds of their engines. In built up areas the vast majority of noise pollution comes from car horns not the vehicles themselves…this won’t change with a gas compression car.
[quote=“Fortigurn”]Only if you refill it using a standard household compressor. Using an industrial compressor at a service station, it only takes 2-3 minutes.
It’s not difficult to see that the compressed air car comes out on top here, very easily.[/quote]
And how much energy does the industrial compressor use? Does it take the same household supply as the one that comes with your car? Or is it a much bigger beast, using far more energy to be able to pump all that air in such a short space of time?
Ultimately, you need enough energy to push the weight of the car and stored energy (fuel, batteries, compressed air, big springs, whatever) down the road. Energy efficiency is a measure of how much energy you have to put in to make that happen.
If you charge a battery at high speed it gets hot. Energy is wasted.
If you compress air at high speed it gets hot. Energy is wasted. I am guessing that the ‘industrial compressor’ you’re talking about would be running full time to compress air into a large tank that would then refill the smaller tank in your car as required, minimising the waste but not actually compressing the air in just a few minutes. However it works, it has to squeeze enough energy into the car to push it down the road.
Let’s say 30Amps x 220 volts = 6600w
6600w * 3 mins = 0.33kilowatthours of energy stored in your car assuming no loss due to heating, which is ridiculous.
How far is your car going to get on that?
Are there any engineers out there who are better at calculating this sort of stuff?
185 mile range under optimal conditions, say cruising at 30mph to reduce wind resistance with no stops or starts. That’s six hours driving.
Er, where have I screwed up? I calculate you have 55 watts of energy available to propel a car at 30mph, under best conditions. Someone do this properly for me.
How much energy is needed to push a 2-seater car made from lightweight materials at 30mph for six hours?
I know it isn’t. So measure it in kWh. Find an industrial air compressor, and a service station petrol pump, and compare the electricity demand of the two devices over 3 minutes. I don’t know these values, so I omitted them.
I actually mentioned that specifically later in my post.
What we can conclude is this:
The compressed air powered car does not emit the same local noise/air pollution as the petrol car (in terms of air pollution, it only emits slightly heated air)
The compressed air powered car requires only one power source (electricity), whereas the petrol car requires two (electricity and petrol)
The petrol car requires the support of the oil industry to provide petrol, creating pollutants in the process
Can you see any advantages here?
I failed to mention it because I wasn’t aware of it. Having said which, I don’t believe it for a moment.
In which built up areas? I hardly hear any car horns at all in Taipei, compared to somewhere like New York. But that aside, you seem not to have addressed the fact that the local noise and air pollution of a compressed air powered car is less than that of a petrol car.
Of course it’s a larger compressor, and uses more electricity than the household supply.
Yes, that’s right. Of course I’m not actually comparing the energy efficiency of the two vehicles, I’m comparing the air/noise pollution and energy demands of the two vehicles. In these terms, I believe the air compressed car is far superior.
I’ll skip your calculations and cut to the chase:
Not very far, which is one of its main advantages over the petrol car. And of course, since it is designed for inner city use, it doesn’t have to go very far.
How many days of inner city driving does it take you to clock up 6 hours of driving? Let’s be really vicious, run the car in sub-optimal conditions, cut the available driving time down to half that, and say you only get 3 hours of driving. How many days does it take you to clock up three hours of driving? When I lived in Australia, 3 hours of driving would mean three and a half days of commuting between my house and my place of work, and that’s between suburbs (50 minutes of driving each day). That’s plenty of range for suburban driving, let alone inner city driving.
There’s simply no comparison with a petrol car. Using a petrol car for inner city driving is just plain stupid.
I know it isn’t. So measure it in kWh. Find an industrial air compressor, and a service station petrol pump, and compare the electricity demand of the two devices over 3 minutes. I don’t know these values, so I omitted them.[/quote]
I can’t be stuffed checking because I know whatever value I come up with doesn’t mean diddly anyway. All the figures quoted for this and that still don’t look at the big picture of what I described previously in terms of looking at the power costs involved in mining, exploration, transporting, purifying and distributing the power whether its coal, gas, oil, nuclear, solar, wind or hydopower. You see thats where 99% of the energy is expended. To then turn around after all of that is ignored and say yeh, so um forgetting about all that, my air compression car is more efficient is just ridiculous.
I can accept that.
[quote=“Fortigurn”]
The compressed air powered car requires only one power source (electricity), whereas the petrol car requires two (electricity and petrol)[/quote]
Eh? As I mentioned earlier you have blinkers on with this. Assuming that your car got its power from nuclear it requires the following energy:
Your ‘clean’ vehicle requires:
Nuclear fuel (Uranium / Plutonium). To get this fuel requires exploring, mining, extracting, purifying. All of that takes plently of energy which is usually extracted with oil which in itself required mining, extracting, purifying and distributing.
building a nuclear power plant takes 25 years to build and ~ 5~ 10 years of energy output put into it before there is a net energy gain…that means if it was operating for ~ 5~ 10 years, it would have produced just as much energy as was required to build it.
Transfer of nuclear to thermal power, to electricity.
Electricity from a power grid…no figures because it depends on the grid, but u have significant loss on the grid
Transfer from grid to kinetic energy and then stored gas underpressure, which is then depressured when transferring to your car.
Inside your car that gas is then transferred into kinetic physical motion.
[quote=“Fortigurn”]
I hardly hear any car horns at all in Taipei, compared to somewhere like New York. But that aside, you seem not to have addressed the fact that the local noise and air pollution of a compressed air powered car is less than that of a petrol car.[/quote]
Its true.
[quote=“Fortigurn”]
Of course I’m not actually comparing the energy efficiency of the two vehicles, I’m comparing the air/noise pollution and energy demands of the two vehicles. In these terms, I believe the air compressed car is far superior.[/quote]
No it isn’t. Only in terms of noise pollution. Your view that the energy demands of the air compressed car is misguided at best.
The only way it could be considered clean, is in the currently unrealistic model of using solar panels (which is perhaps only feasible in Australia and a few other places) to power the gas compressors. Any other way of powering them is still going to require vast inputs of non-clean energy.
[quote=“Fortigurn”]I’ll skip your calculations and cut to the chase:
Not very far, which is one of its main advantages over the petrol car. And of course, since it is designed for inner city use, it doesn’t have to go very far.[/quote]
The calculations are the important thing. I cold easily be wrong, but any competent engineer could show me where by explaining in cold hard numbers exactly how much energy the car would use.
And then he/she would tell me how much petrol a conventional car would use to travel the same difference.
Everything is just opinion, and pointless argument. I don’t have an emotional attachment to burning petrol, I gave up my car voluntarily a few years ago. I’m not interested in ‘winning’ this debate, I’m interested in knowing what method of delivering motive power to the wheels results in the burning of the least amount of fossil fuels.
Obviously, meeting ALL the world’s energy needs from clean sustainable sources is the best option, but until that happens we have to be realistic about what we’re doing.
Any car uses energy to move around, whether the energy is obtained by burning oil, coal or old coconuts. For a given weight of vehicle the amount of energy should be approximately equal, but the efficiency of the transfer/storage system determines how much energy you have to put in to get that same amount of useful energy out.
What percentage of energy input is lost when compressing air at high speed, compared to charging a battery, or replacing a slow-charged battery pack? What percentage is lost throughout the storage process, compared to just transmitting the power directly to the wheels? Answer these questions and you have a measure of how much energy is wasted by each system.
The aim is to cut the waste, to do the least harm, not just to send the pollution elsewhere.
Or, my favourite option, use public transport and walk if you live in an urban environment so that we don’t have to devote such immense resources to building roads and providing healthcare to people injured by motorists on unnecessary journeys.
As a ‘competent’ engineer who studied mining, mechanical and electrical engineering (major), I can tell you that coming up with meaningful figures without using a specific example is almost impossible.
Most figures you see floating around haven’t taken into account a vast number of highly significant factors, but instead are there as marketing BS used simply to mislead the layman or push a political agenda.
Of course the biggest problem is that companies developing this stuff do it to generate a profit whilst ignoring or circumventing as many environmental problems as they can legally because it almost never makes financial sense to care about the environment.
Meanwhile the government whose job it is to protect the environment has more pressing issues at hand such as allowing dirty industries because it will mean cheaper electricity or more jobs, and ultimately thats what wins peoples votes.
I recommend you both watch a doco. called “The end of suburbia” which details exactly how General Motors bought up the railway only to replace it with a motorway because they’d sell more cars that way.
I haven’t said a word about whether or not it’s more efficient. I’m not arguing about whether or not it’s more efficient.
I don’t have to assume that. But I was speaking of power sources, not power supply industries and the power each industry requires for its various processes. You still have this idea that I’m comparing energy efficiency.
Not local air pollution? A compressed air powered car produces the same amount of local air pollution as a petrol car? The same amount of CO2, CO, fumes, whatever? Really?
Do you mean my view that the energy demands of the air compressed care are less than that of the petrol car is misguided? I haven’t actually argued that.
Such as hydro? And really, is it going to be producing the same amount of local air and noise pollution as a petrol car? If we took all the non-commercial petrol vehicles out of Taipei, and replaced them with these, would there be:
More local noise/air pollution
The same amount of local noise/air pollution
Less local noise/air pollution
[quote=“Loretta”]The calculations are the important thing. I cold easily be wrong, but any competent engineer could show me where by explaining in cold hard numbers exactly how much energy the car would use.
And then he/she would tell me how much petrol a conventional car would use to travel the same difference.[/quote]
That would be interesting. But I’m not arguing that the compressed air car is more energy efficient.
I agree. I happen to believe that cars requiring only electricity to power them is a good start, since they can be independent of fossil fuels. You can supply the electricity through solar, wind and hydro power, none of which are fossil fuels. You cannot possibly make a petrol car which can be powered independent of fossil fuels.
I agree. Working on producing vehicles which are independent of fossil fuels has to be part of the solution. As long as we rely on petrol powered vehicles, we’re basically wasting our time, energy, and resources. They’re a complete dead end.
I agree entirely, that’s what I do. But of course you get people saying you’re just sending the pollution elsewhere by using the MRT, which relies on electricity produced by oil, coal, gas, or nuclear power, so you might as well use your petrol car because no real benefits accrue from using public transport. I remain unconvinced by such arguments.
Since I’m not actually trying to argue whether or not the compressed air car is more efficient than the petrol car, I don’t really need meaningful figures. I’m looking at it from the point of view of air and noise pollution. It’s looking pretty good from that point of view. I’m also looking at it from the point of view of independence from fossil fuels. It’s looking pretty good from that point of view also.
When we can make a petrol car which is independent of fossil fuels, and only produces slightly warmed air as a byproduct of being used, that will be an intelligent alternative to this vehicle. Until that time, this vehicle is an intelligent alternative to the inner city use of petrol cars. Inner city use of a petrol car is not intelligent at all.
Here are some specifications for a electrical car (battery powered):
Curb weight (without driver, lead acid batteries): 785 kg
Motor: 72V DC, 13 kW
Batteries: Maintenance-free lead batteries, ca 8.4 kWh or optional ca 10.5 kWh available.
Charging time: 0-100% in 6-8 hours, 30-100% in 3 hours
Range: Lead-acid batteries 50-100 km, depending on road conditions
Battery life: Approx. 20.000km
You will need 8,4 - 10,5 kWh to drive a 785kg car 50-100km.
I guess the energy consumption would be same/similar for compressed air.
Then you need to take onto consideration the energy loss from the power-plant to your power-outlet and loss during charging - how much energy need to be produced at the plant to store 10kWh in the batteries or compressed air-tank, but those calculations are out of my league.
I am sure there are better cars out there, but this is just an example for reference if someone want to calculate power consumption for various alternatives.
Ok, take a hypothetical scenario where the car was twice as big (proper family car) and could travel twice as far so used 4 times the energy (lets say 40 kWhours) and could travel 200km.
Assume that instead of batteries it uses compressed gas and that the energy consumption was the same.
Given that solar cells can provide (low cost ones) 5 KwH/m2/day then assuming you used the car once fully per day, then all it would take is ~ a single metre squared panel a day to precompress enough air to run one of these cars! The great advantage of this system over batteries is that you could have multiple tanks and the storage of compressed gas is quite efficient.
I want to point out that the weight of the battery-pack for the car above is 385kg. If the airtank needed to store similar amount of energy is comparable, then it will be a hell of a job to replace the empty tank with a full one.
With those calculations, it certainly looks like a very viable option.
Attach air hose. Squeeze trigger. Fill tank with air. I’m not sure I see the problem. Certainly no more difficult than filling a 70 litre petrol tank. It’s not as if you have to physically remove the empty tank and replace it with a full one.
[quote=“Fortigurn”]With those calculations, it certainly looks like a very viable option.
Attach air hose. Squeeze trigger. Fill tank with air. I’m not sure I see the problem. Certainly no more difficult than filling a 70 litre petrol tank. It’s not as if you have to physically remove the empty tank and replace it with a full one.[/quote]
Ohh, I see, I was thinking more in terms of replaceable gas tanks we see here in Taiwan - but with air in this case.
Oh, OK. And there was me thinking that pollution was in some way related to the amount of fuel burned unnecessarily because of inefficiencies. There was me thinking that anything which reduced the amount of fuel burned nunecessarily was a good thing. Wasting my time. Sorry, I was trying to address the earlier post you made.
The answer to your question is ‘yes, increasing the amount of electricity we use increases the amount of pollution from the electricity sources you list.’ Do you think that replacing all those cars with electric vehicles can be done without making more electricity?
[quote=“then you”]If we took all the non-commercial petrol vehicles out of Taipei, and replaced them with these, would there be:
More local noise/air pollution
The same amount of local noise/air pollution
Less local noise/air pollution[/quote]
We know the answer to that, but without an increase in efficiency the net amount of pollution will increase. Obviously the debates about global warming, acid rain, the ozone layer, etc have passed you by and you’re only concerned with the immediate impact on yourself in your inner city.
I agree. [/quote]
So I’m confused. What exactly is our point? That compressed air cars don’t burn fuel in cities? No contest. Now let’s talk about the environment, shall we?
In what way does storing energy by means of compressed air in any way at all affect the way in which the energy is obtained in the first place? This device simply sends the pollution elsewhere, and may in fact lead to an increase in the total amount of pollution. It just makes it conveniently go somewhere else so you can pretend it’s not happening.
This vehicle is not independent of fossil fuels and won’t be until the energy to power it is produced from clean sustainable sources.
But at least we agree on something.