tag:blogger.com,1999:blog-1592992209402300549.post4115786070590639536..comments2024-03-29T09:08:47.702-04:00Comments on The Silicon Graybeard: China's Electric Car Dominance? Not So MuchSiGraybeardhttp://www.blogger.com/profile/00280583031339062059noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-1592992209402300549.post-84651463216529549142012-06-14T21:39:48.792-04:002012-06-14T21:39:48.792-04:00I meant to say: so, unless that wall is equal to o...I meant to say: so, unless that wall is equal to or greater than 100% efficiency, electric motors are just NOT worth itSteve Dnoreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-76823031043313994202012-06-14T20:39:18.331-04:002012-06-14T20:39:18.331-04:00So, unless that wall is equal to or less than 100%...So, unless that wall is equal to or less than 100% efficiency, electric motors are just NOT worth it.Steve D.noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-5360032402646205582012-06-14T20:36:34.506-04:002012-06-14T20:36:34.506-04:00Sure, but so long as the electricity comes from fo...Sure, but so long as the electricity comes from fossil fuel, the law of conservation of energy means that a greater amount of energy must be taken from the coal to produce an equal or lesser amount of energy in the battery. So assuming both your energy transfer and your battery are 100% efficient, you can break even. <br />Electric cars, unless their electricity is produced completely by nuclear or hydro (or unless they are made to trash the laws of physics) are an environmentalist’s nightmare, ultimately costing more fossil fuel than they save. Now hybrids, which are not really an electric motor; just a more efficient internal combustion engine are another matter...Steve D.noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-2109565327714459772012-06-10T14:30:59.730-04:002012-06-10T14:30:59.730-04:00Some of those "extra" electrons go into ...Some of those "extra" electrons go into reversing the chemical change that happens during the discharge cycle. You're doing more than just "Refilling the bucket" with what you've taken out.drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-52487503348587715442012-06-10T11:36:51.052-04:002012-06-10T11:36:51.052-04:00The inefficiency of the battery itself is somethin...The inefficiency of the battery itself is something I haven't gone into anywhere. The points of this piece itself were the BS about "Moore's Law of electric car" and the myth that China, because they have mass amounts of unskilled, cheap labor would somehow leap frog the world. <br /><br />I don't recall numbers on battery efficiency off the top of my my head, but I do know that most slow chargers work at .1 capacity for 1.6 times capacity. I'm sure that's just to ensure a full charge was transferred and is more than you need because that says you need to force 160% of the number of electrons into the battery that you took out. It's not an impressive number - but it is better than 30% efficiency in an ICE.SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-46140956290547652562012-06-10T01:28:31.376-04:002012-06-10T01:28:31.376-04:00You know what I recommend that the public-at-large...You know what I recommend that the public-at-large get more than an electric car?<br /><br />A high school physics class. <br />At least.<br /><br />A battery is inefficient. We've been making them smaller, lighter, and more efficient, but we're going to hit a wall, especially with lead/acid batteries. <br />The only thing I think the Chinese have on us when it comes to batteries is that I would be willing to bet theirs has more lead in it. It IS China, after all.Theredneckengineerhttps://www.blogger.com/profile/03356011400643553377noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-12510562936920860032012-06-09T15:27:39.442-04:002012-06-09T15:27:39.442-04:00Thanks for the input, Francis. That's before ...Thanks for the input, Francis. That's before my time in the blogosphere, but for the rest of the readers who might want a little clarification, as I pointed out in <a href="http://thesilicongraybeard.blogspot.com/2012/03/least-you-should-know-about-electricity.html" rel="nofollow">The Least You Should Know About Electricity - DC</a>, a Watt is a joule per second, so 5 MegaJoules is 5 Million Watt*Seconds or 1389 Watt*hours (5,000,000/3600 seconds in an hour). <br /><br />That's a lot of power - roughly a car battery delivering 100 Amps for one hour (or 1A for 100 hours...) (ideally). I think they're thinking more along the lines of thousands of amps in pulses. <br /><br />The kinetic energy of anything is 1/2 (mass*velocity squared), but once the car has been accelerated, the only energy requirement is to overcome the friction losses in the drivetrain and air resistance. Let's say driving a car down the highway takes 20 HP or so (rough guess - depends on a mess of variables). There's 750W per HP or 15,000W; about 10 times the energy in the battery pack Den Beste was talking about. Rough guess, so let's say the energy of a car moving down the road is 20 times the energy of that backpack.SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-55010264889854126082012-06-09T15:00:14.980-04:002012-06-09T15:00:14.980-04:00Absolutely. Well, I guess it also comes from natu...Absolutely. Well, I guess it also comes from natural gas and some tiny proportion from nuclear. The only advantage to the EV is that the energy, once in the battery, goes to a motor that's very efficient compared to an internal combustion engine.SiGraybeardhttps://www.blogger.com/profile/00280583031339062059noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-5906518646722997132012-06-09T09:48:33.680-04:002012-06-09T09:48:33.680-04:00But the power to charge the batteries still comes ...But the power to charge the batteries still comes from burning coal.Steve Dnoreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-82529553472193572402012-06-08T05:51:37.316-04:002012-06-08T05:51:37.316-04:00Way back, when dinosaurs still walked the Earth an...Way back, when dinosaurs still walked the Earth and Steven Den Beste was still blogging at USS Clueless, he noted that the ability to carry 5 MegaJoules of dispatchable electic capacity in a backpack would change warfare forever.<br /><br />Reflect on how little energy that is, compared to what it takes to propel a car at highway speeds. (Yes, a little arithmetic is required.)Francis W. Porrettohttps://www.blogger.com/profile/05862584203772592282noreply@blogger.comtag:blogger.com,1999:blog-1592992209402300549.post-75646698667217013412012-06-07T23:41:24.392-04:002012-06-07T23:41:24.392-04:00Yep, electric cars would be really neat if the bat...Yep, electric cars would be really neat if the batteries didn't SUCK so badly....drjimhttps://www.blogger.com/profile/05647484115197408897noreply@blogger.com