Joel N. Weber II
Engineer
This pdf has some information about the battery pack used in the Tesla Roadster.
The battery pack itself weighs about 450 kg/1000 pounds; the Wikipedia article claims the entire car weighs 2723 pounds, which makes the battery pack a bit more than 1/3 of the car's weight. The range of a Roadster is allegedly around 240 miles.
I'm wondering if it would be practical to build a locomotive hauled train where 1/9th of the weight of the entire trainset were batteries similar to what is found in a Tesla Roadster. Consider, perhaps, a locomotive where half the weight was batteries, and 7 coaches which each weigh about half what the locomotive does. If it turns out that the range is proportional to the fraction of the weight of the automobile or train which is batteries, this trainset might have a range of around 80 miles. If you can partially charge the batteries at the outbound end of a commuter run, and perhaps charge the batteries via catenary while the train runs through the downtown core of the commuter system, I think an 80 mile range might turn out to be viable. I think the majority of MBTA Commuter Rail branches are shorter than 40 miles.
Do we have data for an NJT trainset with a dual mode catenary/diesel locomotive of what fraction of the total trainset's weight is the diesel prime mover?
One thing I'm a little confused by is the Roadster battery paper mentioned above claims the energy in the Roadster battery pack is equivalent to about 8 liters of gasoline, which would appear to be about two gallons. This might suggest the Roadster gets the equivalent of about 120 miles per gallon. I am wondering if they are going on a theoretical physics definition; an internal combustion engine is well under 50% efficient at converting energy in the fuel being burned into forward motion. Perhaps what they mean is that if you wanted to heat a building, the Tesla battery pack is as capable as two gallons of gasoline. But I think converting energy in a battery pack to forward motion is a more efficient process (again, going by theoretical physics definitions) than burning gasoline.
Also, the Roadster battery pack is about 53 kilowatt hours. How long can you run an Amfleet's HEP loads, or a Viewliner's HEP loads, or a Superliner's HEP loads if you fully discharge a 53 kilowatt hour battery pack that starts out fully charged? And would installing a 1000 pound battery pack in each passenger car be practical, in terms of the weight the car can carry?
The battery pack itself weighs about 450 kg/1000 pounds; the Wikipedia article claims the entire car weighs 2723 pounds, which makes the battery pack a bit more than 1/3 of the car's weight. The range of a Roadster is allegedly around 240 miles.
I'm wondering if it would be practical to build a locomotive hauled train where 1/9th of the weight of the entire trainset were batteries similar to what is found in a Tesla Roadster. Consider, perhaps, a locomotive where half the weight was batteries, and 7 coaches which each weigh about half what the locomotive does. If it turns out that the range is proportional to the fraction of the weight of the automobile or train which is batteries, this trainset might have a range of around 80 miles. If you can partially charge the batteries at the outbound end of a commuter run, and perhaps charge the batteries via catenary while the train runs through the downtown core of the commuter system, I think an 80 mile range might turn out to be viable. I think the majority of MBTA Commuter Rail branches are shorter than 40 miles.
Do we have data for an NJT trainset with a dual mode catenary/diesel locomotive of what fraction of the total trainset's weight is the diesel prime mover?
One thing I'm a little confused by is the Roadster battery paper mentioned above claims the energy in the Roadster battery pack is equivalent to about 8 liters of gasoline, which would appear to be about two gallons. This might suggest the Roadster gets the equivalent of about 120 miles per gallon. I am wondering if they are going on a theoretical physics definition; an internal combustion engine is well under 50% efficient at converting energy in the fuel being burned into forward motion. Perhaps what they mean is that if you wanted to heat a building, the Tesla battery pack is as capable as two gallons of gasoline. But I think converting energy in a battery pack to forward motion is a more efficient process (again, going by theoretical physics definitions) than burning gasoline.
Also, the Roadster battery pack is about 53 kilowatt hours. How long can you run an Amfleet's HEP loads, or a Viewliner's HEP loads, or a Superliner's HEP loads if you fully discharge a 53 kilowatt hour battery pack that starts out fully charged? And would installing a 1000 pound battery pack in each passenger car be practical, in terms of the weight the car can carry?
