Stan, A few points: *Never trust numbers from the innumerate. The reporter claims 3.4 kWh/mi but he is wrong. The label clearly states 34 kWh/100 mi, which is 2.9 mi/kWh. More usefully, the figure is 760 kJ/km. The EPA and DoE understand well to wheels numbers, but usually use well to tank, and tank to wheels numbers. The Leaf rating will NOT be energy at the wheels, but metered energy to recharge the battery after the cycle drive. For a gasoline or diesel vehicle, fuel consumed is actually figured from exhaust analysis but is equivalent to metered fuel to refuel the vehicle. The miles driven account for the wheels, so it is (consistently) a tank to wheels analysis.
*The energy policy implications are unclear. I probably agree that with electricity from coal, the Leaf probably has better tank to wheels and worse well to wheels efficiency than the VW. On the other hand, we have abundant (dirty) coal and import both crude and refined petroleum products from nations basically hostile to us. We could, if we had the national will, generate electricity from nuclear reactors. All the political issues are off-topic to metrication, but the issues may be worth noting. The can of worms divides into pro-worms and con-worms. *Please check your electricity cost. I believe you may have dropped a zero. Otherwise, you pay a staggering $2.16/kWh (I pay $0.13) *The Volt has just been rated http://www.autoblog.com/2010/11/24/2011-chevy-volt-gets-93-mpge-and-37-mpg-rating-from-epa/ In electric mode, it is rated 93 mpge or 36 kWh/100 mi with a 35 mi E-range. In gas mode, it is rated 37 mpg, or 2.7 gal/100 mi, with 344 mi G-range ________________________________ From: Stanislav Jakuba <[email protected]> To: [email protected] Cc: U.S. Metric Association <[email protected]> Sent: Wed, November 24, 2010 10:14:02 PM Subject: Re: [USMA:48922] RE: new fuel economy label under review by EPA Re: Re: Nissan Leaf Cost may have been a good criterion in simpler times when gasoline was the universal fuel, when there was no EPA, subsidies, highway & state gas taxes, etc. It is nearly impossible to find out what the $ cost of the heat content of a fuel is within the maze of the ever-changing laws and regulations that determine the price "at the pump." Today, that is; it may be different tomorrow. And what will be the "gas tax" on electric vehicles that pays for their share of the road use? I do not see that ever included with the Volt, Leaf, etc. promotions. It is easier to determine the ENERGY usage of cars. If electricity is produced from fossil fuels, 9.5 % to 13.5 % of the heat is used for propulsion, the difference guided by, surprise, the efficiency of charging. A study showing this is attached. Diesel cars use much less energy, and can be lighter, all else equal (such as special tires, aerodynamic shape, etc), for the battery that is heavy even when "empty." A friend, automotive engineer driving diesel cars all his life and keeping meticulous records, claims his VW averages 0.6 m/kJ ("over 50 mls/gal") thru the 3 years of ownership. That is 1.6 kJ/m (or 1.6 MJ/km as might be preferred). My friend is meticulous also in observing speed limits, thus most of us, law-disobeying citizens, would get less, perhaps 0.5 m/kJ. Adding the approx. 20 % loss of energy used in drilling, refining and distribution of liquid fuels, that leads to 0.4 m/kJ or 2.5 MJ/km "at the well." The Leaf uses 3.4 miles/kWh which is 1.5 m/kJ. This is at the wheel rather then the power from the battery pack, I presume. From the attached table then the "at the coal mine" energy efficiency is 0.31 m/kJ to 0.22 m/kJ, about 1/2 the diesel car. I do not know if the Leaf's stated economy includes car heating, a substantial concern where I live (that heat is free with fuelled cars). Coming back to the cost, we pay here in New England 0.6 $/MJ of electricity at the home outlet and 0.02 $/MJ of heat in liquid fuel at the pump. The present cost handicap of the electric car is obvious. It would not change much even if charging at night only, the cost of rewiring a house and eventually whole towns nothwithstanding. When (and if) renewable energy starts providing more than the negligible amount of electricity into the grid the cost will come again into the picture. Wind made electricity is about twice the cost as that from thermal plants with present subsidies. It will be many times more without them and with all costs included such as wind mills foundations, utilities extra expenses, etc. Without nuclear power plants providing the electricity, el. cars have no future except thru Gov't mandate. Ironically, that is the situation under the same Gov't that suppresses the production of cheap, reliable electricity enabled by nuclear energy. Stan Jakuba On Wed, Nov 24, 2010 at 6:48 AM, John M. Steele <[email protected]> wrote: Fuel costs vary too much. Any assigned standard cost to the fuel will always look dumb in a few months or a few years as prices bounce up and down. > >We should metricate but they will never buy that suggestion. With miles and >gallons, we should change to a measure of gallons per thousand miles: >*Many people drive about 12000 miles per year or 1000 miles per month >*Integer precision would suffice for gallons per 1000 miles >*This measure better shows the savings of a more fuel efficient car (vs miles >per gallon) > > > > ________________________________ From: Stan Doore <[email protected]> >To: U.S. Metric Association <[email protected]> >Sent: Wed, November 24, 2010 6:13:57 AM >Subject: [USMA:48921] RE: new fuel economy label under review by EPA Re: Re: >Nissan Leaf > > >Rather than focus on MPG, the focus should be on cost per mile or cost per 100 >kilometers regardless of fuel. >Stan Doore > > >From:[email protected] [mailto:[email protected]] On Behalf Of >Ron >Stone >Sent: Wednesday, November 24, 2010 3:54 AM >To: U.S. Metric Association >Cc: U.S. Metric Association >Subject: [USMA:48919] new fuel economy label under review by EPA Re: Re: >Nissan >Leaf > >a new fuel-eonomy label is under consideration by the EPA. > >http://www.epa.gov/fueleconomy/label.htm > >there is also a form to submit a comment to the EPA. > >Ron > >On Tue, Nov 23, 2010 at 11:58 PM, John Frewen-Lord <[email protected]> >wrote: >From the link given below: > >"So, how does the EPA calculate mpg for an electric car? Nissan's presser says >the EPA uses a formula where 33.7 kWhs are equivalent to one gallon of >gasoline >energy. Also, the EPA determined the Leaf's efficiency is 3.4 miles per kWh, >another number you can easily beat while driving, as the driver info screen >can >prove. Since the Leaf has a 24 kWh battery pack and can go, officially, 73 >miles, then, the EPA says, it could theoretically go 99 miles if it had a 33.7 >kWh pack (and everything else about the car remained the same). Make sense?" > >In a word, no! It's a pity though, since the EPA had to design a new label, >they didn't include metric equivalents. That would have (a) started on the >road >to getting those Americans who have never come across metric units more >familiar >with them, and (b) highlighted the absolute absurdity of making these >conversions in the first place. The text from this article sure confused me >until I read it for the third time. > >John F-L >----- Original Message ----- >>From:Pat Naughtin >>To:U.S. Metric Association >>Sent:Wednesday, November 24, 2010 4:19 AM >>Subject:[USMA:48916] Nissan Leaf >> >>Dear All, >> >>See http://www.autoblog.com/2010/11/22/nissan-leaf-snags-99-mpg-rating-on-official-epa-sticker >> >> >>Earlier I mentioned the cost of the "metric conversion" approach to >>metrication. >>I wonder how much this lot of metric conversion cost already and how much it >>will cost in the future. This car was most likely designed by Nissan in >>Japan, >>built wholly using metric units, particularly the millimetre, and then tested >>using joules, watts kilograms, and kilometres. One wonders whether one of the >>design goals was to get below 2 megajoules per kilometre. >> >>Finally, all the metric units have been hidden though the metric conversion >>processes to comply with the regulations of the Environmental Protection >>Agency >>in the USA. I ask again, "At what cost?" >> >>Cheers, >> >>Pat Naughtin >>Author of the ebook, Metrication Leaders Guide, see >>http://metricationmatters.com/MetricationLeadersGuideInfo.html >>Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY >>PO Box 305 Belmont 3216, >>Geelong, Australia >>Phone: 61 3 5241 2008 >> >>Metric system consultant, writer, and speaker, Pat Naughtin, has helped >>thousands of people and hundreds of companies upgrade to the modern metric >>system smoothly, quickly, and so economically that they now save thousands >>each >>year when buying, processing, or selling for their businesses. Pat provides >>services and resources for many different trades, crafts, and professions for >>commercial, industrial and government metrication leaders in Asia, Europe, >>and >>in the USA. Pat's clients include the Australian Government, Google, NASA, >>NIST, >>and the metric associations of Canada, the UK, and the USA. >>See http://www.metricationmatters.com/ to subscribe. >> > > > >-- > >-------------------- >Ron Stone >------------------------- >disclaimers or other restrictions may apply to this message. >------------------------------------ >
