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A fun usage of dimensional analysis: Fuel capacity of a diesel electric locomotive: 6200 gallons Energy density of diesel fuel: 40kWh/gal Total energy capaci
by jaggederest 8y ago
A fun usage of dimensional analysis:
Fuel capacity of a diesel electric locomotive: 6200 gallons
Energy density of diesel fuel: 40kWh/gal
Total energy capacity of full fuel load: 248 megawatt hours
Tesla battery pack weight: 540kg
Tesla energy capacity: 85kWh
Weight of equivalent battery pack for a diesel locomotive:
248 MWh / (85 kWh / 540 kg) = 1575 metric tons
Weight of a diesel locomotive: 196 metric tons
So you'd roughly 10x the weight of a locomotive by trying to make it run on batteries, leaving aside the challenges of actually trying to charge those batteries.
Another fun fact: that locomotive can run flat out at max power for 2.2 days without refueling.
- swish_bob 8y agoOf course, while it's neither easy, nor cheap, that train does not need to have any batteries in order to run on electricity. Much of the UK's rail network is either electrified or in the process of being electrified. The side effect of not needing to use energy to haul your energy source around is pretty cool, too.