 # How much would the energy eq. of 1 gallon of gas cost in a PHEV

Does anyone see problems with my math?

Plug in Hybrid electric vehicles are supposed to hit the market soon. Here is what I calculate for the cost of the equivalent of gallon of gasoline.

Gasoline is 125,000 BTU/gallon of which 20% is converted to mechanical energy. so 25,000 BTU = 26,376 KJ. 1 KWH = 3,600 KJ. Assuming 85% of battery energy is converted to mechanical energy in a PHEV that means you need 31030 KJ of energy to get the energy equivalent of a gallon of gasoline. With electricity at about 9.5 cents kwh and you need 8.6 KHW of electricity, that comes to 82 cents for the equivalent of a gallon of gasoline.

http://www.onlineconversion.com/energy.htm

I went a different route - assumed 1 US gallon of gasoline weighs 2.72 kg and contains 47 MJ per kg energy, plugged in your 20% and 85% assumed efficiencies, and came out with 8.3 kWh required, which is close enough.

So no, I see no problem with your math.

Sweet. Electric cars will run on the equivalent of 80 cent a gallon gasoline.

There’s a group in Palo Alto called the California Cars Initiative that’s working on plug-in hybrids and their website also suggests an equivalent cost of under one dollar per gallon.