to your HTML Add class="sortable" to any table you'd like to make sortable Click on the headers to sort Thanks to many, many people for contributions and suggestions. Licenced as X11: http://www.kryogenix.org/code/browser/licence.html This basically means: do what you want with it. */ var stIsIE = /*@cc_on!@*/false; sorttable = { init: function() { // quit if this function has already been called if (arguments.callee.done) return; // flag this function so we don't do the same thing twice arguments.callee.done = true; // kill the timer if (_timer) clearInterval(_timer); if (!document.createElement || !document.getElementsByTagName) return; sorttable.DATE_RE = /^(\d\d?)[\/\.-](\d\d?)[\/\.-]((\d\d)?\d\d)$/; forEach(document.getElementsByTagName('table'), function(table) { if (table.className.search(/\bsortable\b/) != -1) { sorttable.makeSortable(table); } }); }, makeSortable: function(table) { if (table.getElementsByTagName('thead').length == 0) { // table doesn't have a tHead. Since it should have, create one and // put the first table row in it. the = document.createElement('thead'); the.appendChild(table.rows[0]); table.insertBefore(the,table.firstChild); } // Safari doesn't support table.tHead, sigh if (table.tHead == null) table.tHead = table.getElementsByTagName('thead')[0]; if (table.tHead.rows.length != 1) return; // can't cope with two header rows // Sorttable v1 put rows with a class of "sortbottom" at the bottom (as // "total" rows, for example). This is B&R, since what you're supposed // to do is put them in a tfoot. So, if there are sortbottom rows, // for backwards compatibility, move them to tfoot (creating it if needed). sortbottomrows = []; for (var i=0; i
GM (formerly known as "General Motors") announced today that its new combination electric battery and gasoline engine powered vehicle, the Chevrolet Volt, will have a MPG rating of 230 miles per gallon. To obtain that rating, GM collaborated with its fellow government entity, the EPA (also known as the "Environmental Protection Agency"), to produce a "new methodology for determining a draft fuel economy standard for extended-range EVs like the Volt." (HT: Coyote Blog.)
Tim Haab did some math this morning and worked out that mileage rating equates to a trip of just 51.11 miles, 40 of which are assumed to be solely powered by the car's electric battery-powered system before the car's gasoline engine takes over for the remaining number of miles. Tim goes the extra mile in finding out what the comparative cost would be for operating the Volt:
The Chevy web-site notes that the EPA will rate the Volt as using 25 KwH of electricity/100 miles driven for an average price of $.75 to $2.50 per 100 miles driven on electricity. At $2.50 per gallon and 50 mpg, the same 100 miles would cost the driver $5 driving on gas.
We're going to look at the Volt from a different angle, however. In addition to noting that the 230 MPG figure only applies to city driving, CNN reports that though the Chevy Volt may cost less for gasoline, the vehicle is still expected to be pretty expensive. And as it happens, the Chevrolet Volt will be subsidized by the government with taxpayer dollars to make it more attractive to consumers, which is noted by GM's government-installed CEO, Fritz Henderson:
The EPA rating for the Volt is based on a draft report and applies to city driving. Henderson said GM is confident that when Volt's combined city/highway mileage average is calculated, it will be over 100 mpg.
But GM is obviously focused on the 230 mpg estimate as part of its early marketing campaign for the vehicle. It unveiled a logo with the number 230, with the zero looking like a cross between a smiley face and electrical plug.
GM started pre-production of the car in June is making about 10 a month. "Volt is becoming very real, very fast," Henderson said.
Henderson conceded the cost of building a Volt will be expensive, about $40,000 per vehicle. But he said the vehicle will qualify for a $7,500 tax credit, which will reduce the vehicle cost by that amount for consumers.
He also stressed that GM has not set the pricing for the Volt, and conceded the company may have to subsidize the vehicle. The goal: Make enough sales to move the Volt from "first generation" to lower-cost future designs.
"The cost of the vehicle in the first generation is high," he said.
But does that truly generous $7,500 tax credit subsidy cover the high cost of the Volt's electric battery-powered drive system?
In covering the development of electric powerplants for use in aviation, we've previously cited sources indicating that:
Conventionally powered airplanes with the performance of electric ones use only one or two gallons of fuel an hour, so the difference in direct operation cost is negligible in comparison to the difference in initial outlay: for an airworthy gasoline engine, $100 per horsepower; for an electric powerplant, $400 or more per kilowatt.
Let's assume that the difference in direct operating costs between gasoline and electric power for cars is likewise negligible compared to the cost of the engine systems providing the power, and that the chief difference between the costs of each are what you pay up front for the vehicle itself. Let's also assume that the relative costs of the different kinds powerplants for cars are the same as that for airplanes.
With those assumptions, a gasoline engine would cost $133 for every kilowatt of energy it produces, while an electric powerplant would cost $400 for every kilowatt of energy it produces, a difference of $267 per kilowatt-produced.
TheCarConnection's Marty Padgett reports that the Volt can be powered for the first 40 miles of its range by a 16 kwH battery, whose "220 lithium-ion battery cells produce the equivalent of 150 horsepower and 273 pound-feet of torque." Multiplying that 16 kwH battery capacity by the $267/kwH difference between a gasoline engine and electric powerplant, we can estimate the increased cost of the Volt's battery-powered system over a gasoline-powered system to be around $4,224.
On an interesting side note, with today's best practical batteries weighing around 15 pounds per kilowatt-hour of energy stored, we would estimate that the Chevy Volt's 16 kwH lithium-ion battery to weigh roughly 240 pounds. The amount of gasoline that could produce the same amount of energy as the Volt's battery would weigh 2.8 pounds. At nearly the average weight of a NFL player, we'll note that the battery would actually impair the fuel efficiency of the Volt's gasoline powered system after it has expended its store of energy.
Assuming that the costs of successfully integrating the two different kinds of engines and the unitized costs of their respective manufacturing systems work out to average less than $3,276 per vehicle, the taxpayer provided subsidy would cover the higher cost of the vehicle.
What a nice gift for the eco-conscious from U.S. taxpayers!
Image Credit: DailyTech.
Labels: economics, environment
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