$this->bbcode_second_pass_quote('pstarr', 'y')esplease, I got some science for ya
$this->bbcode_second_pass_quote('Pimentel and Patzek', 'T')able 3. Average Inputs and Energy Inputs Per Hectare Per Year
for Switchgrass Production
----Inputs----------------------------Quantity----kcalx1000
Labor----------------------------------5 hr-----------------20
Machinery---------------------------30 kg----------------555
Diesel------------------------------100 L ----------------1,000
Nitrogen---------------------------50 kg ----------------800
Seeds-----------------------------1.6 kg ----------------100
Herbicides------------------------3 kg ------------------300
Total 10,000 kg yield ----------------2,755
40 million input/ 1:14.4k
kcal yield output ratio
Table 4. Inputs Per 1000 l of 99.5% Ethanol Produced From U.S. Switchgrass
----Inputs----------------------------Quantities----kcal x 1000
Switchgrass------------------------2,500 kg---------694
Transport, switchgrass------------2,500 kg-------300
Water-------------------------------125,000 kg-------70
Stainless steel---------------------3 kg---------------45
Steel--------------------------------4 kg----------------46
Cement-----------------------------8 kg---------------15
Grind switchgrass------------------2,500 kg-------100
Sulfuric acid------------------------118 kg---------------0
Steam production------------------8.1 tons----- 4,404
Electricity---------------------------660 kWh------1,703
Ethanol conversion to 99.5%-----9 kcal/L-----------9
Sewage effluent-------------------20 kg (BOD)-----69
Total-------------------------------------------------7,455
Inputs per 1,000 l of ethanol: 7,455,000 kcals. Outputs per 1000 l of ethanol: 5,130,000 million kcal.
Therefore, in Pimentel’s words it: “requires 32% more fossil energy to produce 1 liter of ethanol using 2.5 kg switchgrass than the energy in a liter of ethanol."