Thanks for pointing that out. Due to the time limitations on my speech, I did not go through the calculations properly and verbally mixed numbers from different scenarios. The main mistake was that in actual use @ 2,900 watts, the gas was used at a rate of 0.4 gallons/hour, not 1.7, which is the estimated usage rate driving at 75 MPH. Bottom line is that I believe that the calculation of the cost is correct, but ignores the wear & tear on the car, in particular the cycling of the high voltage battery. Since this is only for emergencies, I don't really have to be concerned about that. The more complete version is: Gas usage while charging: 0.7 Gallons/hour Duration engine on: 3.3 Minutes Duration engine off: 2.5 Minutes Total cycle duration: 5.8 Minutes Duty cycle: 57% Gas usage rate 0.40 Gallons/hour Power output 2,900 Watts (per spec.) Output @ 100% 5,097 Watts Compared to driving: Car gets 45 MPG Average speed 75 MPH (Guestimate) Gallons/hour 1.7 Gallons/hour Charging = to driving at 31.5 MPH If gas costs $4.00 /Gallon Using PriUPS costs $1.59 /hour @ 2,900 Watt configuration Cost of electricity is $0.55 /KWH
@@GaryMLauder *not write, but right (my mistake in the first message). :) Simplier, effectiveness of electricity GENERATING of Prius is equal to petrol generator (1kWt=1liter of petrol) which is not as good as for diesel generator (1kWt=0.7 liter of diesel fuel). And during constant high loads Prius worse than diesel generator and equal to petrol one. But at inconstant loading Prius has some agvantage as it has buffer battery and spends electricity more effectively.
That's what I was thinking too.
If you use 1.7 Gal/hour and price $4/Gal - using PriUPS costs $6.8/hour, but not $1.59/hour.
Am I write?
Thanks for pointing that out. Due to the time limitations on my speech, I did not go through the calculations properly and verbally mixed numbers from different scenarios. The main mistake was that in actual use @ 2,900 watts, the gas was used at a rate of 0.4 gallons/hour, not 1.7, which is the estimated usage rate driving at 75 MPH. Bottom line is that I believe that the calculation of the cost is correct, but ignores the wear & tear on the car, in particular the cycling of the high voltage battery. Since this is only for emergencies, I don't really have to be concerned about that.
The more complete version is:
Gas usage while charging: 0.7 Gallons/hour
Duration engine on: 3.3 Minutes
Duration engine off: 2.5 Minutes
Total cycle duration: 5.8 Minutes
Duty cycle: 57%
Gas usage rate 0.40 Gallons/hour
Power output 2,900 Watts (per spec.)
Output @ 100% 5,097 Watts
Compared to driving:
Car gets 45 MPG
Average speed 75 MPH (Guestimate)
Gallons/hour 1.7 Gallons/hour
Charging = to driving at 31.5 MPH
If gas costs $4.00 /Gallon
Using PriUPS costs $1.59 /hour @ 2,900 Watt configuration
Cost of electricity is $0.55 /KWH
@@GaryMLauder *not write, but right (my mistake in the first message). :)
Simplier, effectiveness of electricity GENERATING of Prius is equal to petrol generator (1kWt=1liter of petrol) which is not as good as for diesel generator (1kWt=0.7 liter of diesel fuel). And during constant high loads Prius worse than diesel generator and equal to petrol one.
But at inconstant loading Prius has some agvantage as it has buffer battery and spends electricity more effectively.