[biofuel] Re: diesel or hybrid?
Hello Biofuel folks, I am reposting this message that I originally put up on the evworld server. The original message was on this list, but it got reposted. Please understand that I am doing so here hoping that someone will provide a counter point which will educate me more on biodiesel. Thanks. Forbes Bagatelle-Black I am going to go out on a limb here and say that I would buy the Prius. Not that the TDI would be a bad choice! In terms of protecting the environment right here and now, I would say that the choice is a wash. Both vehicles presents significant benefits in terms of clean emissions. However, looking into the effect your choice will have on the future of transportation technology, I think buying the Prius today now will do the most good at the present time. I say this because of several reasons, including: 1. Electric drivetrain technology needs our support right now. With the Bush administration gutting funding to the pure EV industry, it is critically important that research on battery and motor technology be supported by other means. Hybrid vehicle development does support this technology, but research being done in hybrid development will have benefits to vehicular design which go far beyond the hybrid electric/gasoline industry. 2. Supporting hybrids will result in demonstrable benefits to biodiesel-powered vehicles. As others have posted, a diesel/electric hybrid would combine many of the benefits from both technologies. Correct me if I am wrong here, but I seem to remember that some of the extremely high-efficiency diesels have a fairly peaky efficiency curve. They like to stay in their sweet spot efficiency-wise. A hybrid diesel/electric drivetrain would allow them to do so. 3. Diesel drivetrains are approaching their theoretical peak efficiency points. This makes battery and motor technologies (especially battery technology) the long poles in the tent. Investing in these technologies now will help bring them up to par with internal combustion technologies. Now, I readily admit that I am biased. I know a lot more about hybrids and pure electrics than about biodiesel, so I am hoping that a biodiesel expert will offer an educational counterpoint. Respectfully, Forbes Bagatelle-Black --- In biofuel@yahoogroups.com, Thor Skov [EMAIL PROTECTED] wrote: I'd like to pose a question to forum. I am considering swapping my 2001 Golf TDI for another car, one that is an automatic rather than a stick. I have to do a lot of driving for my job (about 90 miles a day), and although I prefer stick driving, the clutching is bothering my pelvis and leg. So, I am contemplating getting either a new Jetta TDI wagon (I really like the VWs) or the second generation toyota Prius. The question for me is what type of technology should I support, from the standpoints both of environmental impact and incentives to auto manufacturers. On the one hand, I want to be able to continue to burn biodiesel, which makes up approximately 1/4 of my fuel consumption--more if the proposed subsidy goes through (assuming World Energy drops its prices accordingly and/or the Ferndale plant actually starts producing sometime this decade). Biodiesel has good environmental benefits, gets decent mileage (maybe 45 mpg with the automatic), and is a great conversation item with which to get people thinking about sustainability. Also, there is the option to convert to SVO down the road. I don't have a feel for the extent to which my purchase will encourage VW and other european firms to start selling more high-efficient diesel models in the U.S. On the other hand, the new Prius gets considerably better mileage, and is a SULEV/PZEV. Not being carbon neutral withstanding, it pollutes much less than the TDI. Toyota is far out in front of Detroit (and Europe) in hybrid development, and there is something to be said I think for rewarding that innovation. U.S. automakers haven't even put out a first generation hybrid vehicle and Toyota is already working on its third generation. Any thoughts? thor skov p.s. I'd really prefer a jetcar, if I could get one! = Sentiment without action is the ruin of the soul. --Edward Abbey Grants Manager, Stillaguamish Tribe Of Indians P.O. Box 277 Arlington, WA 98223-0277 Phone: (360) 652-7362 Ext 284 Fax: (360) 435-7689 Yahoo! Groups Sponsor -~-- Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark Printer at MyInks.com. Free s/h on orders $50 or more to the US Canada. http://www.c1tracking.com/l.asp?cid=5511 http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/FGYolB/TM -~- Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do
[biofuel] Re: how much do you know
Dear Guy, If you were travelling through a perfect void in outer space, you could turn off the engine and coast. You would not slow down. However, we live on the earth, where we have to deal with friction. In automotive applications, friction shows up as air resistance, rolling resistance, and drivetrain inefficiency (although it is not the only component of drivetrain inefficiency). All these factors can be dealt with numerically. Please let me know if you would like the equations. Yours, Forbes --- In biofuel@yahoogroups.com, GuyW [EMAIL PROTECTED] wrote: There is no energy consumed simply because an object is travelling at a certain velocity; an object in motion tends to stay in motion. If this were true, we'd just turn off the engine and coast... -Guy- Yahoo! Groups Sponsor -~-- Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/ySSFAA/FGYolB/TM -~- Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
[biofuel] Re: how much do you know
At the speeds we are discussing, wind resistance accounts for most of the energy consumed. Other sources of energy consumption are rolling resistance of the tires, which remains constant relative to velocity (but not vehicle mass), and inefficiencies in the drivetrain and engine. Drivetrain inefficiencies remain relatively constant. Engine efficiencies, on the other hand, vary greatly largely as a function of actual torque at a given RPM and peak torque at that RPM. Efficiency tends to increase as actual torque approach peak torque. There is no energy consumed simply because an object is travelling at a certain velocity; an object in motion tends to stay in motion. Of course, there is energy consumed when accelerating or climbing a hill. The amount of energy consumed during acceleration or altitude gain is directly proportional to the mass of the vehicle in question, which is also the case for rolling resistance. I have developed an acceleration modeling program which demonstrates many of these concepts. Let me know if anyone would like to play with it and I will send it along. I can also send a full set of the applicable equations. Respectfully, Forbes --- In biofuel@yahoogroups.com, Martin Klingensmith [EMAIL PROTECTED] wrote: What you described is a doubling in the energy consumed by air friction, not the net energy due to the increase in velocity. Martin Klingensmith nnytech.net infoarchive.net Yahoo! Groups Sponsor -~-- Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/ySSFAA/FGYolB/TM -~- Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
[biofuel] Re: how much do you know
A friend of mine tried something like this several years ago on a human powered vehicle he was racing. He used fans to pull the air going by closer to skin of his vehicle, causing air flow which aproximated a laminar flow more closely. I am not sure how successful he was, but everything made sense. Forbes --- In biofuel@yahoogroups.com, gobie [EMAIL PROTECTED] wrote: - Original Message - From: Forbes Bagatelle-Black [EMAIL PROTECTED] At the speeds we are discussing, wind resistance accounts for most of the energy consumed. Other sources of energy consumption are rolling resistance of the tires, which remains constant relative to velocity (but not vehicle mass), and inefficiencies in the drivetrain and engine. Drivetrain inefficiencies remain relatively constant. Engine efficiencies, on the other hand, vary greatly largely as a function of actual torque at a given RPM and peak torque at that RPM. Efficiency tends to increase as actual torque approach peak torque. Now here is one from the weird ideas department. What if we could reduce the wind resistance by mechanical means. Wind resistance increasing vastly as speed increases, mechanical energy requirements increasing less. Would need something like a moving skin on the vehicle same speed as the air. Its alright folks, very early in the morning here, gpoing to get some sleep , will be back to normal in a few hours. Yawns, Paul Gobert. Yahoo! Groups Sponsor -~-- Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/ySSFAA/FGYolB/TM -~- Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
[biofuel] Re: how much do you know
Air resistance goes up dramatically as a function of speed, per the following equation: Power = 0.5*Cd*FA*V^3 where Power is the power consumed by the vehicle Cd is the drag coefficient of the vehicle FA is the frontal area of the vehicle V is the speed of the vehicle Using this equation, you can see that it takes more than twice as much power for the same vehicle to go 70mph as it does to go 55mph (2.06 times as much power). Energy is power * time, so differences in energy usage will not be quite as dramatic as differences in instantaneous power usage, but they will not be very far off. Of course efficiency plays a major role in the equation also. Engineers can design a drivetrain to be most efficient at whatever speed they choose, but most of the time that V^3 term overwhelms any efficiency differences. Respectfully -Forbes Bagatelle-Black --- In biofuel@yahoogroups.com, Tim Castleman [EMAIL PROTECTED] wrote: how much do you know that reducing the speed limit again would help? Personally, I can only offer that it is simple physics. It takes energy to move mass, and more energy to move mass faster. Certainly technology has improved the efficiency of vehicles, but technology has yet to circumvent the laws of physics. A simple test one can very effectively do would require a bicycle. Peddle hard and get it going as fast as you can, then try to maintain that speed. It should not take long to notice a significant loss of speed without a great investment of more and more energy. We can also look at some of the work done in 1995, which is admittedly a bit old, but helpful. http://www.epa.gov/otaq/reports/env-spds.htm http://www.trucktires.com/library/technical/bftechnical/fuel_economy_b .htm Of course I could be wrong about the actual percentages, there are certainly a great many variables to consider, but I am not wrong that it requires more energy to move mass faster. Slowing down will save energy. Finding a compromise between standing still and movement is the real issue. This is why safety, pollution, cost, and time all enter the equation. I would certainly welcome any contribution to help clarify and substantiate or disprove the starting points of 20% to 50% reductions that I have derived from historical documentation I found so far. [Non-text portions of this message have been removed] Yahoo! Groups Sponsor -~-- Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/ySSFAA/FGYolB/TM -~- Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ Please do NOT send Unsubscribe messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
