On Mon, Aug 2, 2010 at 8:27 PM, Leland Jackson <[email protected]> wrote: > 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). > ------------------------
Diesel engines mtbf is the best available today. These assets are built for 15+ years so you put the best torque for the $$. The difference is power transmission between engine to axle that you are failing to account for. You can take a single generating "car" and then have 2,3,4 battery storage+engine cars depending on what you need to haul. You are only moving electricity between cars in this case and that is the most conservative in loss compared to mechanical between cars. -- Stephen Russell Sr. Production Systems Programmer CIMSgts 901.246-0159 cell _______________________________________________ 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.
