Generator Calculations

       New information provided by the graduate students at the field station can be used to estimate the energy production of the generator. The amount of gasoline burned in the generator corresponds to total energy created based on accepted values for the energy density of gasoline. One liter of gasoline contains 34 megajoules of energy, stored in the chemical bonds of each hydrocarbon molecule [1]. The energy produced is also affected by the amount of energy lost in the form of heat, unburned fuel, exhaust, friction, and engine cooling. A typical engine will run at around 25 to 30 percent efficiency [2]. Generators, in their conversion of mechanical energy to electrical, operate at around 60-70 percent. For the calculations, it can be assumed that the generator is 20% efficient in converting the chemical energy in gasoline to electrical.

Energy produced by the generator:

Assume: 5-6 liters are consumed, 34MJ/L of gasoline (energy density), 20% efficiency

Max:

20%*34MJ/L*6L(1hr/3600s)=11.3kWh

Min:

20%*34MJ/L*5L(1hr/3600s)=9.4kWh

These values,11.3 and 9.4kWh, are the upper and lower bounds of the energy produced by the generator in a period of usage, burning 5 to 6 liters of fuel. While this is the energy produced, this is not the amount of energy typically consumed at the station. The difference is lost in the form of heat, unbruned fuel, and electrical resistance. The purpose of the battery storage system would be to store all the energy produced by the generator at one time in the batteries. Then this energy could be utilized later on more efficiently.

[1] "Energy in natural processes and human consumption" Internet: http://www.ocean.washington.edu/courses/envir215/energynumbers.pdf, [13 May 2012].
[2] "Fuel Economy: Where the fuel goes" Internet: http://www.fueleconomy.gov/feg/atv.shtml, [15 May 2012].