First, as a former resident of Arizona, there certainly are plenty of areas which have the needed
resources of flat land, water (most proposals are for nearly sealed bioreactors, so water resources
are not nearly as severe as the New Mexico NREL studies suggest). As for sources of CO2, there is
no requirement to SUPPLY the bioreactors with anything other than atmospheric amounts of CO2. Having
an electric plant nearby to feed CO2 is a definite benefit to yields, but significant yields can be
achieved without the supply of external CO2.
The NREL studies looked at over 3000 different strains of algae and other micro-organisms, a great
many are suitable for biodiesel production, depending on the environment (temperature, sunlight, etc).
Depending on the area selected for production, different strains of algae will do better than others.
The biggest problem is that a sealed environment (where the atmosphere is filtered before introduction
to the bioreactor) may be required due to native species of algae (windblown spores) out-competing
the desired strain. This will drive up the cost of the production of vegetable oil, but not nearly
as high as some posters on the thread in question claim.
In any event, when compared to the other biofuels oil production per acre... algae is a clear winner.
http://www.unh.edu/p2/biodiesel/article_alge.htmlhttp://journeytoforever.org/biodiesel_yield.htmlCrop US gal/acre
corn (maize) 18
cashew nut 19
oats 23
lupine 25
kenaf 29
calendula 33
cotton 35
hemp 39
soybean 48
coffee 49
linseed (flax) 51
hazelnuts 51
euphorbia 56
pumpkin seed 57
coriander 57
mustard seed 61
camelina 62
sesame 74
safflower 83
rice 88
tung oil tree 100
sunflowers 102
cocoa (cacao) 110
peanuts 113
opium poppy 124
rapeseed 127
olives 129
castor beans 151
pecan nuts 191
jojoba 194
jatropha 202
macadamia nuts 240
brazil nuts 255
avocado 282
coconut 287
oil palm 635
Algae, from the NREL study, can produce from 5,000 gal/acre to 20,000 gal/acre, which dominates the
other candidates on this list. Not to mention that algae is very picky about the water supply,
and can be used with sewage and brackish (salty) water.
In addition, the amount of energy needed to grow 5000 gallons/acre/year of algae would need to be
compared to the amount needed to grow 5000 gallons/N acres/year of other biodiesel crops. I suspect,
but haven't seen the studies, that the amount of energy needed for the equivalent amount of diesel
fuel is much, much less (no tractors, no fertilizer, just a water pump and oil press).