On 08/02/2010 05:53 PM, Michael Madigan wrote: > But why to they have a diesel engine powering the electric generator > providing power to the electric engines that actually power the train? > Wouldn't it make sense just to power the train directly from the diesel > engine if there was no efficiency reason?
That's what I was thinking. Just for the sake of argument, suppose the diesel engine is 60% efficient at ideal rpms. Therefore, running the diesel engine to put electricity into the batteries creates a 40% loss in efficiency. There could another 5% loss in efficiency, while the energy is being stored in the battery. If the electric engine is 90% efficient then you lose another 10% efficiency when the electric motor is running. Total loss in efficiency would then be 55%, (eg 40% diesel, 5% battery, and 10% electric motor, so where's the advantage. Perhaps, like the hybrid car, the gain comes from storing the energy from the petrol, while the transportation is not in motion, (e.g. at idle). Regards, LelandJ > --- On Mon, 8/2/10, john harvey<[email protected]> wrote: > > >> From: john harvey<[email protected]> >> Subject: RE: [OT] unaffordable at any speed >> To: "'ProFox Email List'"<[email protected]> >> Date: Monday, August 2, 2010, 6:47 PM >> The secret to trains "efficiency" is >> very little friction between steel >> rails and stell wheels. The highway and rubber tires can't >> compare.... >> >> >> John >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] >> On Behalf >> Of Stephen Russell >> Sent: Monday, August 02, 2010 4:31 PM >> To: ProFox Email List >> Subject: Re: [OT] unaffordable at any speed >> >> On Mon, Aug 2, 2010 at 3:54 PM, Leland Jackson<[email protected]> >> wrote: >> >> >>> It could take decade to make the transition in any >>> >> significant way to >> >>> the electric cars, and the electric motor is not well >>> >> suited to >> >>> transport by air, ship, rail, and 18 wheelers that do >>> >> the heavy lifting >> >>> in commercial transportation of goods to the consumer, >>> >> which is the >> >>> heart and life blood of an economy. I don't see a >>> >> total transition to >> >>> the electric car. I think the electric car will >>> >> become just another >> >>> option like petrol or diesel cars. >>> >> ---------------- >> >> Rail moves by electricity for engine power. Produced >> onsite in diesel >> generators but it is electric motors that make fast quiet >> trains. >> >> A decade is not much time to start to replace what is there >> by 15-25% >> >> I don't see a huge JUMP from our current power source to a >> new one. >> Starting to actually consider a different one is what will >> be great. >> >> Wonder if you took the diesel power in a tractor / trailer >> and >> converted that to power generation for battery instead and >> coupled it >> to an electric motor like trains do if there would be an >> advantage. >> When you read or heat the rail quotes of cost per ton of >> freight to >> move it is incredible. >> >> >> >> -- >> Stephen Russell >> >> Sr. Production Systems Programmer >> CIMSgts >> >> 901.246-0159 cell >> [excessive quoting removed by server] _______________________________________________ Post Messages to: [email protected] Subscription Maintenance: http://leafe.com/mailman/listinfo/profox OT-free version of this list: http://leafe.com/mailman/listinfo/profoxtech Searchable Archive: http://leafe.com/archives/search/profox This message: http://leafe.com/archives/byMID/profox/[email protected] ** All postings, unless explicitly stated otherwise, are the opinions of the author, and do not constitute legal or medical advice. This statement is added to the messages for those lawyers who are too stupid to see the obvious.
