Photon Guy Posted August 16, 2021 Posted August 16, 2021 I briefly talked about this before on this forum about the process of how a car works, gasoline burns and in doing so gives off kinetic energy which goes through a bunch of processes (pushing pistons, turning gears, ect.) until finally it gets to the wheels and serves its intended purpose, moving the car forward. Anyway I believe it was mentioned here that about 80 percent of the energy is lost, its lost in the form of heat and friction. If only 20 percent of the energy is used to make the car go that's quite inefficient, can we make cars more efficient?
Sensei Posted August 16, 2021 Posted August 16, 2021 35 minutes ago, Photon Guy said: can we make cars more efficient? 1) decrease mass of car/vehicle and fuel usage per kilometer will drop too. Engineers can use e.g. Aluminium alloys, Magnesium alloys, carbon fiber etc. And these technologies are used in more expensive cars. 2) use KERS to recover kinetic energy of cars during braking. 3) city electric cars don't need extra large battery (i.e. decreased mass of car), if they can be wirelessly and/or quickly charged on/by road e.g. waiting on traffic lights. And alternatives: 1) More home office = less traffic = less people killed on roads = more time spend with family and friends. 2) Free (and electric) public transport = less traffic = less killed on roads = controlled creation of energy & pollution in power stations. 3) creation of alcohol from air CO2 and water in special factories and usage instead of oil fuel. 39 minutes ago, Photon Guy said: If only 20 percent of the energy is used to make the car go that's quite inefficient, can we make cars more efficient? Oil & gas industry wants to increase carbon fuel usage, not limit it.. If behind a series of financial institutions controlling car making companies are also owners of oil&gas companies, decreased fuel usage of cars will affect their other investment. 1
Ken Fabian Posted August 16, 2021 Posted August 16, 2021 (edited) An ICE using petro-chem fuel that is 100% energy efficient is still making CO2 emissions. An EV or biofuel car built and running off 100% clean energy doesn't make CO2 emissions. It doesn't have to have 100% energy conversion efficiency to do so, just zero emissions energy; even wasteful energy and inefficient energy use will have zero emissions. Efficiency is a slippery concept; in a world where fossil fuels are abundant, cheap and there is no accountability for climate and other externalised costs (climate, health) the energy conversion efficiencies don't really matter. What people pay matters but not conversion efficiency. Where fuels are expensive conversion efficiency matters more. Where fuels come with externalised costs (climate, health) greater efficiency reduces those costs but only a shift to clean energy can eliminate them. Edited August 16, 2021 by Ken Fabian 1
Peterkin Posted August 16, 2021 Posted August 16, 2021 Just as matter of interest: 2 hours ago, Ken Fabian said: biofuel car What biofuel would power private passenger vehicles?
Sensei Posted August 16, 2021 Posted August 16, 2021 (edited) 26 minutes ago, Peterkin said: Just as matter of interest: What biofuel would power private passenger vehicles? Biofuel is mostly ethanol. Biofuel has one large disadvantage: if farmers earn more from plants for biofuel, they don't produce plants for food. Which can lead to increased price of food for people and farm animals.. Ethanol can be dehydrated to ethene and used for production of plastic and other organic compounds. Edited August 16, 2021 by Sensei
Peterkin Posted August 16, 2021 Posted August 16, 2021 I know what it is. I was wondering about the specific source of that much biofuel. Corn is an environmental and economic disaster. Other grains are sorely needed for food. Algae?
swansont Posted August 16, 2021 Posted August 16, 2021 8 hours ago, Photon Guy said: I briefly talked about this before on this forum about the process of how a car works, gasoline burns and in doing so gives off kinetic energy which goes through a bunch of processes (pushing pistons, turning gears, ect.) until finally it gets to the wheels and serves its intended purpose, moving the car forward. Anyway I believe it was mentioned here that about 80 percent of the energy is lost, its lost in the form of heat and friction. If only 20 percent of the energy is used to make the car go that's quite inefficient, can we make cars more efficient? Internal combustion is part of the problem - typically pretty low thermal efficiency of ~20-25%. Diesel is generally better. Getting away from the combustion format altogether is probably where the big improvement is. Electric motors are more like 75-80% efficient, and benefit directly from things like regenerative braking.
TheVat Posted August 16, 2021 Posted August 16, 2021 The old-school EVs, that were conversions, still retained the inefficiencies of the traditional drive train where a single electric motor was coupled to two wheels. The later ones, with separate motors on each drive wheel (and the differential done electronically), reached those 75-80% numbers. I don't know if those numbers could (in terms of economical feasibility) be bumped up farther.... maybe more aerodynamic "teardrop" shapes, and some sort of ground-effect. Biofuels always seemed like a scam, something for cornbelt politicians to pitch to farming communities and Big Ag. When you factored in all the fossil fuel burned in the raising of the crop, transporting and processing and cooking it to make the fuel, plus the algal blooms and other riparian and marine water problems from the fertilizer runoff, it wasn't very "green. " I think algae, as @Peterkin mentioned, grown basically from solar power, is a bit better, but still works off the ICE model.
swansont Posted August 16, 2021 Posted August 16, 2021 I was referring to the motors themselves. All else being equal, going from even a 30% efficient ICE to a 75% efficient electric motor seems like a big win. And that's before you consider Ken F's point about CO2 reduction (which would be maximized if you got your electricity from a green source) At some point efficiency bumps up against the utility of the vehicle. If the aerodynamic shape means you can't carry the stuff you want to carry, your potential customer population shrinks. 20 minutes ago, TheVat said: Biofuels always seemed like a scam, something for cornbelt politicians to pitch to farming communities and Big Ag. Ethanol seems very much in this category. Unclear on the benefits other than corporate welfare. Other efforts seem niche and it's not clear to me that they scale very well.
dimreepr Posted August 16, 2021 Posted August 16, 2021 13 hours ago, Photon Guy said: can we make cars more efficient? That's the wrong question to ask... A more pertinent question is, can we make car's more effective?
Peterkin Posted August 16, 2021 Posted August 16, 2021 Cars, as they are now and as they're envisioned for the near future, convey passengers and baggage from one place to another reliably and quickly. In what way should a car be more effective?
exchemist Posted August 16, 2021 Posted August 16, 2021 21 minutes ago, Peterkin said: Cars, as they are now and as they're envisioned for the near future, convey passengers and baggage from one place to another reliably and quickly. In what way should a car be more effective? By not requiring everyone to own one, for a start. It's grossly inefficient use of resources, when you think about it. I think that driverless cars, that you summon when you need one, would be a far more efficient system.
Peterkin Posted August 16, 2021 Posted August 16, 2021 (edited) 9 minutes ago, exchemist said: By not requiring everyone to own one, for a start. It's grossly inefficient use of resources, when you think about it. I think that driverless cars, that you summon when you need one, would be a far more efficient system. Of course, reducing the absolute number of vehicles on any road (like closing downtown to all but foot-traffic, and restricting narrow streets to bicycles only and main streets to public transport) is an excellent idea. So is improvement of mass transit, both urban and highway. So are the driverless taxi cabs and vans (though self-driving cars have been getting some pretty bad press). But that doesn't make each vehicle more effective or more efficient. I wondered what Dimreepr meant by that distinction. Edited August 16, 2021 by Peterkin two unwanted words
studiot Posted August 16, 2021 Posted August 16, 2021 13 minutes ago, exchemist said: By not requiring everyone to own one, for a start. It's grossly inefficient use of resources, when you think about it. I think that driverless cars, that you summon when you need one, would be a far more efficient system. Sadly, that dream is fraught with many perils. Would you recommend everyone in a household or block of flats uses the same toothbrush so there is only one toothbrush?
exchemist Posted August 16, 2021 Posted August 16, 2021 1 hour ago, studiot said: Sadly, that dream is fraught with many perils. Would you recommend everyone in a household or block of flats uses the same toothbrush so there is only one toothbrush? Not a good analogy, I think. Zipcar already offers a service whereby you hire a car by the hour when you want one. I have a friend who does this in preference to the cost and bother of owning her own car. If you live in a flat, in a row of terraced houses, which is true of much of Victorian London for example, car ownership is distinctly a mixed blessing. Parking is already a problem. Having to charge an electric car in the street will be even worse. If you add to that the convenience of not having to drive the bloody thing, you can go to a party and have a few drinks, or watch a film or something while you are in transit. Sort of like Uber, but without the risk of getting raped, or catching Covid from the driver. I would agree this makes most sense in towns and cities, but I can see it coming quite fast, with electric vehicles. 1 hour ago, Peterkin said: Of course, reducing the absolute number of vehicles on any road (like closing downtown to all but foot-traffic, and restricting narrow streets to bicycles only and main streets to public transport) is an excellent idea. So is improvement of mass transit, both urban and highway. So are the driverless taxi cabs and vans (though self-driving cars have been getting some pretty bad press). But that doesn't make each vehicle more effective or more efficient. I wondered what Dimreepr meant by that distinction. Sure. At the level of the individual vehicle, the first thing must be to get away from heat engines, limited as they are by Carnot cycle efficiency constraints. While a lot of electricity is still generated by fossil-fuelled heat engines today, they are a lot more efficient than a car engine. Renewable generation sources, which are growing, avoid the problem. A hydrogen vehicle could be powered by a heat engine, which won't be any more efficient than today's vehicles, or by a fuel cell system, which should be better. But currently, hydrogen generation is itself inefficient, so I understand, unfortunately.
CharonY Posted August 16, 2021 Posted August 16, 2021 7 minutes ago, exchemist said: Not a good analogy, I think. Zipcar already offers a service whereby you hire a car by the hour when you want one. I have a friend who does this in preference to the cost and bother of owning her own car. If you live in a flat, in a row of terraced houses, which is true of much of Victorian London for example, car ownership is distinctly a mixed blessing. Parking is already a problem. Having to charge an electric car in the street will be even worse. If you add to that the convenience of not having to drive the bloody thing, you can go to a party and have a few drinks, or watch a film or something while you are in transit. Sort of like Uber, but without the risk of getting raped, or catching Covid from the driver. In some major cities alternatives (or cabs, which could be considered a shared car of sorts) are more popular or affordable than car ownership. I have read that in parts of New York City car ownership is down to 22% (which is quite significant as elsewhere in the US the average ownership is closer to two cars per household). In Singapore car ownership is so expensive that ownership is only around 10% though they also have a great transit system. While a transit system tends to be more efficient energy -wise, in some areas car sharing might work better. The benefits of the latter might be saved resources from production. Whether it saves operating emissions might depend on whether folks are willing to share the same drive.
Peterkin Posted August 16, 2021 Posted August 16, 2021 13 minutes ago, exchemist said: While a lot of electricity is still generated by fossil-fuelled heat engines today, they are a lot more efficient than a car engine. Renewable generation sources, which are growing, avoid the problem. Cleaner, cheaper, quieter, neater! Any reason there can't be a wind turbine and a solar array over, and the best available storage battery under, every charging station? https://www.energy.gov/energysaver/hybrid-wind-and-solar-electric-systems 3 minutes ago, CharonY said: In some major cities alternatives (or cabs, which could be considered a shared car of sorts) are more popular or affordable than car ownership One such alternative is clean, cheap, quiet and and healthy.
CharonY Posted August 16, 2021 Posted August 16, 2021 9 minutes ago, Peterkin said: One such alternative is clean, cheap, quiet and and healthy. Well, but also impractical for a range of purposes.
Peterkin Posted August 16, 2021 Posted August 16, 2021 14 minutes ago, CharonY said: Well, but also impractical for a range of purposes. But very practical for the purpose it serves. As is every other form of transport. Different kinds or vehicle for different environments and uses. Of course, all of this is very much beside the point of the OP question.
studiot Posted August 16, 2021 Posted August 16, 2021 (edited) 1 hour ago, exchemist said: Not a good analogy, I think. 1 hour ago, CharonY said: In some major cities alternatives (or cabs, which could be considered a shared car of sorts) are more popular or affordable than car ownership. I freely admit the toothbrush example was extreme for effect. However the topic is about making existing cars more efficient (and deciding what that means). Substituting other forms of transport, limiting their use and so on is surely off topic ? However I view greater 'efficiency' as fraught with perils. And rather insulting to motor engineers as well. I well remember the time when some practical people had the large square Volvo estate and many more aspired to have one but could not afford to. You could get a (several) standard 8 x 4 sheet into one of those. Volvo used to advertise their safety record, as their cars were built safe and sturdy all round. However they were heavier than average and less aerodynamically efficient. So they were less fuel efficient. Yes you can make an IC car more fuel efficient by reducing the panel size, doing a way with the chassis, load capacity, reducing the size of battery it has to carry and many more such savings, perhaps remove the aircon. But such vehicles are demonstrably less safe to drive. Now let us look at this dream 2 hours ago, exchemist said: I think that driverless cars, that you summon when you need one, would be a far more efficient system. Let us say you live in a dormitory town/village of say 15,000 working people. There is such a town near Exeter. Now let us ask if 10,000 of those people want a car at 0830 in the morning to get them to work (in Exeter) for 0900. Now let us consider that Mr Smith's car arrives, but the last use was to ferry four drunk students home the previous night. Not only were they drunk but they went by the curry takeaway and left all of their rubbish in the vehicle, and two of them threw up into the bargain. Who will police this ? So let us look at reducing uneccessary journeys from the point of view of the uneccessary journeys police. Should the right of 5 million football fans to attend away games every week be curtailed ? This would certainly reduce the 'efficiency' of trnasport systems by taking something away. And how about the uneccessary journeys police ? We recently had that high profile case of "Is it necessary to drive up to the (nearby) Peak District for some mental health well being during the Covid pandemic. The efficiencies always affect ordinary folks whicls the rich and powerful are insulated. The BBC did a recent freedom of information act survey of our government departments concerning which Ministers and Ministries were 'environmentally friendly' and published some very sad results. The Department of the Environment has no (yes zero) electric or hybrid vehicles. Boris will not give up his diesel (yes polluting diese) car. Nor will the Minister of Transport and many more I give you the words of whoever wrote the short story Repent Harlequin, said the Tick Tock Man Edited August 16, 2021 by studiot
SergUpstart Posted August 16, 2021 Posted August 16, 2021 I have an idea how to make long-range trucks more efficient. They must have combined wheels that will allow them to move both on rails and on highways. For the transfer between remote cities, trucks are linked and the locomotive takes them from one city to another, upon arrival at the place, they are uncoupled and each goes to its destination. 1
exchemist Posted August 16, 2021 Posted August 16, 2021 (edited) 20 minutes ago, studiot said: I freely admit the toothbrush example was extreme for effect. However the topic is about making existing cars more efficient (and deciding what that means). Substituting other forms of transport, limiting their use and so on is surely off topic ? However I view greater 'efficiency' as fraught with perils. And rather insulting to motor engineers as well. I well remember the time when some practical people had the large square Volvo estate and many more aspired to have one but could not afford to. You could get a (several) standard 8 x 4 sheet into one of those. Volvo used to advertise their safety record, as their cars were built safe and sturdy all round. However they were heavier than average and less aerodynamically efficient. So they were less fuel efficient. Yes you can make an IC car more fuel efficient by reducing the panel size, doing a way with the chassis, load capacity, reducing the size of battery it has to carry and many more such savings, perhaps remove the aircon. But such vehicles are demonstrably less safe to drive. Now let us look at this dream Let us say you live in a dormitory town/village of say 15,000 working people. There is such a town near Exeter. Now let us ask if 10,000 of those people want a car at 0830 in the morning to get them to work (in Exeter) for 0900. Now let us consider that Mr Smith's car arrives, but the last use was to ferry four drunk students home the previous night. Not only were they drunk but they went by the curry takeaway and left all of their rubbish in the vehicle, and two of them threw up into the bargain. Who will police this ? So let us look at reducing uneccessary journeys from the point of view of the uneccessary journeys police. Should the right of 5 million football fans to attend away games every week be curtailed ? This would certainly reduce the 'efficiency' of trnasport systems by taking something away. And how about the uneccessary journeys police ? We recently had that high profile case of "Is it necessary to drive up to the (nearby) Peak District for some mental health well being during the Covid pandemic. The efficiencies always affect ordinary folks whicls the rich and powerful are insulated. The BBC did a recent freedom of information act survey of our government departments concerning which Ministers and Ministries were 'environmentally friendly' and published some very sad results. The Department of the Environment has no (yes zero) electric or hybrid vehicles. Boris will not give up his diesel (yes polluting diese) car. Nor will the Minister of Transport and many more I give you the words of whoever wrote the short story Repent Harlequin, said the Tick Tock Man I'm not suggesting anyone will police anything. There is no need to go off the deep end like some Republican anti-masker (only kidding😄). I'm suggesting that in cities - I did say cities- I can easily see driverless cars, that you summon like a taxi, could replace private car ownership for a lot of people, if it is done well. As my previous posts have pointed out, the elements are already there: services such as Uber and Zipcar are already popular. (Zipcar and Uber have systems to clean cars, obviously. It works already today. So this objection is not real.) As @CharonYpoints out a few posts up, Singapore and New York already show the trends I have in mind. Once it works well in the cities, it can expand from there. Don't forget also that the next generation of potential car owners - people like my 18yr old son- are questioning very seriously whether they should have a car at all, due to environmental impact. I think we could underestimate the extent to which the new generation is willing - eager, even - to do things differently from their fuddy-duddy, climate-destroying parents. Edited August 16, 2021 by exchemist
TheVat Posted August 16, 2021 Posted August 16, 2021 5 hours ago, swansont said: I was referring to the motors themselves. All else being equal, going from even a 30% efficient ICE to a 75% efficient electric motor seems like a big win. And that's before you consider Ken F's point about CO2 reduction (which would be maximized if you got your electricity from a green source) At some point efficiency bumps up against the utility of the vehicle. If the aerodynamic shape means you can't carry the stuff you want to carry, your potential customer population shrinks. Ethanol seems very much in this category. Unclear on the benefits other than corporate welfare. Other efforts seem niche and it's not clear to me that they scale very well. Yes, my post was rushed and I should have made clear I was quite aware of the vastly greater efficiency of an electric motor, no matter how it's coupling to the wheels. I'm likely to have my next car be an EV especially given that my state's grid is presently 70% clean energy, one of the best in the nation in that respect. Ground-effect I only mention whimsically, given it's likely cost for personal vehicles. (the savings in road repair, and therefore in fresh asphalt, might be something, though...)
studiot Posted August 16, 2021 Posted August 16, 2021 10 minutes ago, exchemist said: I'm not suggesting anyone will police anything. No you didn't you obviously believe in a Nirvana of model citizens. But at the same time you have singularly avoided my real points, particularly the one about peak demand and the one about safety. Peak demand and unnecessary journeys are linked to current planning theory which dictates we build huge housing areas widely separated from workplaces, thereby causing millions of unnecessary journeys every day. Why is the Amazon superwharehouse not located in the Middle of Edinburgh? A more sensible approach would be to remember the dairies of yore, most of which operated a fleet of electric delivery 'floats'. A good start would be to force all (perhaps large) distribution operation supermarkets to emulate them, reducing the several thousand cars that can be counted in the car parks of my town, during most days of any week.
Peterkin Posted August 16, 2021 Posted August 16, 2021 38 minutes ago, studiot said: Now let us ask if 10,000 of those people want a car at 0830 in the morning to get them to work (in Exeter) for 0900. No, they obviously want a safe, fast, clean, quiet commuter train with comfortable seats, plenty of leg-room, a holder for one's thermos and good lights to do the crossword, maybe a changing cubicle in case they jogged to the station instead of taking one of shuttles..... That's if they're still commuting to a downtown office in that enlightened retrofuture.
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