2 ms·
economically a net loss or ecologically? I sort of assume both, but I'd like to hope for one of them.
by eximius 9y ago
economically a net loss or ecologically?
I sort of assume both, but I'd like to hope for one of them.
- someguydave 9y agoBoth. Here's some data from the late Prof. MacKay: http://www.withouthotair.com/Errata.html#284 http://www.withouthotair.com/Errata.html#284 : " 1 acre produces 122 bushels of corn per year, which makes 122 x 2.6 US gallons of ethanol, which at 84000 BTU per gallon would mean a power per unit area of {0.2 W/m^2}; however, the energy inputs required to process the corn into ethanol amount to 83,000 BTU per gallon; so 99% of the energy produced is used up by the processing, and the net power per unit area is about {0.002 W/m^2}. The only way to get significant net power from the corn-to-ethanol process is to ensure that all co-products are exploited; including the energy in the co-products, the net power per unit area is about 0.05 W/m^2."