You process the cellulose from plants that grow now like corn stalks. Corn for food and stalks for cellulose. There is no extra water required.

I still have big concerns about how we keep the manmade cellulose-eating bacteria genie from eating good forms of cellulose. If we successfully create a prolific bacteria with the cellulosic appetite of a Costa Rican termite, what is going to stop it from eating wood studs in walls, forests, wheat straw, or the foundation of an entire ecosystem?

History is full of examples of man importing exotic species to solve one problem, but end up creating far greater problems.

This technology can't hurt and might help. But it is only a short term answer. Creating biofuels does not asnwer the need to replace hydrocarbon burning as a source of energy. We need cleaner methods that are unlimited in capcity and intrinsically much smaller in the size or effort needed to extract the energy.

Fusion is coming; and that is the true answer. Combined with the Electric substitutes for transportation, we will no longer need to waste prodigious amounts of effort, in burning enormous quantities ofhydrocarbons, irrespective of whether the source is long dead or only recently created hydrocarbons.

Anaerobic microorganisms consuming organic matter (cellulose, proteins, fat, alcohols, etc.) are very widespread in nature. It is abundant in swamps, soil, intestinal of cows, elephants, ants, even humans (it makes human fart combustible). Symbiosis of anaerobic microorganism and animals (and insects) is very beneficial to both: animals supply food, microorganisms digest it in steps, and animals consume part of semi-digested cellulose, other vice unusable. For ruminants (cows, sheep, goat, moose, deer) it is just a lifeline. Current human dietary recommendation to eat more fibers makes direct use of anaerobic biota in human guts and colon: part of intermediate products of anaerobic digestion of fibers – propionic, butyric, and acetic acids – are adsorbed into bloodstream and are beneficial to health.

Industrial use of anaerobic digestion is also widespread: it is used to treat organic sludges/wastes from food industry and to treat activated sludge at sewage treatment plants. Valuable fertilizers and biogas are bonus products of such treatment.

All enzymatic cellulose ethanol and butanol technologies make use of natural anaerobic microorganisms, beginning with pioneering in the field Iogen corp. of Ottawa. Their particular strain of hydrogenasa enzymes is derived from mold eating uniforms and cotton tents of American JI during WW2 in Pacific. Iogen sold same enzymatic products to companies producing jeans, to stonewash them according to the old fashion. It helped Iogen to survive when oil was cheap and nobody seriously invested in cellulosic ethanol.

Anaerobic biota constantly mutates naturally. Some strains are reported to learn consume coal: in US NE in couple of places sewage sludge was pumped into abandoned coal mines, anaerobic microorganism mutated and learned somehow to consume organic molecules found in coal. Extremely robust anaerobic complexes were found in elephant and termites intestinal.

Anaerobic microorganisms are always loose to much more robust aerobic biota, when oxygen (air) is available. Their energy pass to skim small energy available from reduction of long organic molecules into elementary refuse of methane and carbon dioxide yields much less energy than in aerobic pass, where all digestible organic in presence of oxygen is reduced to carbon dioxide and water. There is no danger from releasing of enhanced anaerobic strains into the nature: it is not even remotely competitive to aerobic biota.

Fusion was coming in the 70s;it was just around the corner. It still is. Continued reliance on the elusive magic bullet to solve our problems is part of the recipe for disaster. Even if we had fusion, would be have the wisdom to use it wisely? Of course not. We have already shown our lack of foresight and prudence with respect to the way we have used and abused the resources we have.

Stan

Alternatively, a few dozen large updated fission nuclear power plants could safely produce all the excess electric power required for 200+ million PHEVs and BEVs for the next 40 to 50 years.

Of course, wind, solar, waves, geothermal, hydro power etc could meet part of the demand.

It's marvelous what nature has been up to hese last millenia, While the apes recline in caves or down the beach, wich reminds me, summers here and the world is there already to enjoy.
As we dont have to desighn that one, just respect the one we have. Look at it this way:
We area curious specie with curious brains in a curious world so curious minds in interesting times learn intersting facts in conventional ways.
So what If I prefer termites this week, and get to know them more intimately. And ultimately they may in time get to Know us and our needs - more than just greed.
in this brave new world.

Also, there's plenty of green energy to be had.
http://greyfalcon.net/greenenergy.png

Some wag said "Fusion has been 20 years away for the last 50 years".  Still seems true.

Off-peak power is produced primarily by coal, and burning coal puts out nearly twice as much CO2 per unit energy produced as petroleum. Running cars on coal does not solve our global warming problem. Coal fired power plants would like to increase their off-peak output, since it allows them to run more efficiently and profitably, but it means burning much more coal at night.

Perennial cellulosic biomass crops are quite water efficient. They depend on rainfall for their water, not irrigation. Production of cellulose is accomplished at low fertility levels. It is seed,fruit and vegetable production that requires high water and nutrients.