Quote:
Originally Posted by JRMichler
That Nikola truck has got to be vaporware. A PT6 gas turbine is rated for 500 to 1000 hp depending on which version. It has specific fuel consumption of 0.67 lbs/hp/hr (Wikipedia). That's almost double the fuel consumption of a truck diesel engine.
What would be the cost and weight of a 320 KwH battery pack?
That size battery pack would allow running an engine at its best efficiency point until the pack was charged, then shut off and run off the battery. The losses from charging/discharging the battery would need to be less than the efficiency gain from running the engine at its BEP in order to show a net gain.
An interesting idea, but TANSTAAFL.
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The nice thing about turbines is that almost all of the energy loss is exhaust heat. So while turbines are very inefficient by themselves, they are a great application for waste heat recovery systems. If you go far enough with that, they beat diesels, sometimes nicely. However, I'm yet to see a truck with a turbine more efficient than a diesel.
Serial hybrid has an efficiency drop of roughly 20% on a highway, when the energy path misses the battery. Going through the battery wastes another 10-20%.
Highway is where haul trucks spend most of their time and fuel, so this is the most relevant scenario.
Yes, this looks like a vaporware.
Oh, BTW, they tend to spec out turbine SFC with kerosene which has lower energy density than diesel.