Energy-Water Follies, Jatropha Edition

I’ve got this energy-water hammer, and they all look like nails right now. Today’s nail is jatropha, one of the next-gen bio-energy darlings. Or not:

Jatropha, a biofuel crop favoured for its ability to grow in areas not suitable for food, may be about to become less popular.

A new Dutch study shows it uses 20,000 litres of water to produces one litre of jatropha biodiesel – more than the other crops used for biodiesel, rapeseed and soybean; and a lot more than ethanol crops such as maize (corn).


  1. Jatropha may or may not be a good idea, but using a lot of water doesn’t necessarily make it a bad idea.

    By the time they’re 10, farmkids likely learn the general idea of Liebig’s law of the Minimum, if not the formal term.

    Plant growth is limited by whatever is in least supply:

    Of these, water is often the limiter, and it is especially trorublesome because it’s the most variable.

    But, if one has decided to grow fuel crops in competition with food crops (and humans have for a long time, called trees), and if there is already more than enough water in an area to grow *anything*:

    – preferably by rain
    – but perhaps in natural flows, including floods you can’t get away from.

    then water is *not* the limiter, and it really doesn’t whether crop A uses more water than crop B.

    I would certainly not think of growing jatropha in NM, but in Nicaragua it might make perfect sense. Farmers don’t try to grow the same crops every where, because conditions differ. See how many varieties there are, jsut of wheat, for example.

    The argument over food crops versus fuel crops comes mostly from folks who don’t seem to understand that it takes *energy* to do farming and transport it to the consumers.

    After the one the one-time fossil fuel energy capital has been spent (or left in the ground for climate reasons), exactly how will one run a (modern) farm and then transport food from where few people livfe to where most people live?

    – Hopefully, lots of electricity.
    – But, there will still need to be some fuel, for a long time. If we’re really lucky, somebody like Nate Lewis will indeed make direct PV->hydrogen work well.

    – But otherwise, someone, somewhere will be growing fuel crops on land that might also grow some food … just like classic old farms devoted some area to wood stands for firewood.

    – Likewise, as broken as US farms subsidies are, especially with regard to corn, it is not completely irrational for a place like Iowa (which doesn’t really have oil and has to import it, with zero control over price), to want to grow some of their own, either to use, or to sell at prices that tend to be linked to oil.

  2. The analogy to woodstands is intriguing. Farms may well resort to growing biomass to feed their own energy inputs. This is an interesting idea; maybe they’ll have some sort of cheap crude burner/boiler contraption on site.

    But that isn’t what we are talking about. We are talking about liquid fuels for transportation.

    As an insurance policy, I suppose there is some appeal for Iowa to have some maintained infrastructure for turning corn into liquid fuel, but that is only if there is a net positive EROEI. In fact, it appears that there is not one, unless the books are pretty severely cooked. So the whole exercise is foolishness. (a fact, by the way, which limits my confidence in the Waxman-Markey process pretty severely)

    Green folk are all concerned (far too much so, I think) about how far their food is shipped. This is for the most part silly because food is high value per weight. Unless they are very poor and live on a few cents worth of low quality grain per day, food shipment costs will have little direct impact, and they are not a major player in global change issues.

    I think people should be more concerned about steel, concrete, lumber; the stuff of large scale construction, which has low cost per weight and is much more sensitive to shipment costs.

    Raw biofuel, it turns out, is in the latter category. It is very low value per weight and spectacularly low per bulk. In order to maintain a positive EROEI, the first phase of production, i.e., bulk refinement, must be very local.

    Our quandary is not running out of energy. It is running out of cheap energy. This being the case, the return per acre on biofuels is constrained to be very small.

    So the confluence of factors to support crops to liquid fuel is not common: enough water to support growth of non-food crops but some other limitation on food crops, enough local capital and infrastructure (including political stability) to support local small scale refineries and a large scale network to collect the first-stage refined product for possible further processing and distribution to customers.

    It turns out to be a very marginal prospect when you put this all together. Some people will possibly be able to make a living at it, but it’s very far from a silver bullet. Optimistically about 10% of current supplies of fuel is what I heard.

    I think it’s already been demonstrated that corn ethanol does impact the food costs of the desperately poor, but obviously those costs are small. Presumably we would pony up. But it’s doubly crazy to irrigate for it; crazy in the way it’s already crazy to grow rice and cotton in the desert, and doubly so because it is a very low value per acre crop. So I agree with John’s basic point; this is not a major competitor for water.

    The more industrial sunlight-to-algae process seems more promising to me, but it is many years away from cost-competitive. If it works, though, New Mexico is a fine place for it.

    Failing that, though, this whole biofuel business looks marginal. Like hydroelectricity, worth doing and likely having big local impacts, but not a major player on the global stage.

  3. Pingback: Jatropha Curcas Biodiesel » Blog Archive » jfleck at inkstain » Energy-Water Follies, Jatropha Edition

  4. Again, this is not a plea to rush out and converts lots of places to biofuels, which I generally think of as last resort. It’s hard to see how much air travel exists in the long term without biofuels, but I wont’ be around to see that.

    We’ve previously been over the (currently-low) transport costs to get food from the farm to the consumer, and I’m not into the irrational “buy-only-local thing either) … but one really needs to look at the entire oil consumption in USA for the entire process and infrastructure, not just the final RR/truck cost, some of which has nonobvious subsidies. (Do big trucks really pay for their wear and tear on roads, for example?)

    Again, I invite a serious analysis of Iowa, just to pick a concrete example, but representative of a big chunk of the US and Canada, and actually, any place that has somewhat-mechanized farming.
    THIS IS NOT A FEW LOCAL PLACES, it’s a big chunk of the US and Canada.

    From the USDA,we can see the ag stats for Iowa.
    Note that the mean farm size is 331 acres, although the distribution is important, since it is of course right-skewed.

    By looking at the farm acreage, number of people in rural areas and number of jobs there, one can get gross estimates:

    24 acres/person
    56 acres/job

    [It is of course quite difficult for anyone to farm 20+ acres of row crops without mechanized help, or maybe horses. Among other things, when it’s time to harvest, you sometimes have a narrow window, and you have to do it speedily, hence 300HP combines…)

    Corn ethanol is (somewhat) an accident of having long-established corn varieties, machinery for planting and harvesting, dense energy in the kernels, grain trucks to take it to elevators, and further distribution onward, for better or worse.

    A thought question:: which is a better use of *field* corn (i.e., msot of what’s grown, not sweet corn that people eat directly):

    a) Feed pigs and cows.
    b) Turn into High Fructose Corn Syrup and other sweeteners.
    c) Turn into ethanol to reduce use of oil.

    This, see esp. page 2 shows where Iowa (and US) corn actually go. Corn is a “push”, which is why HFCS is pervasive, as per Michael Pollan in Omnivore’s Dilemma.

    Still, very little Iowa corn goes into food actually purchased by poor people (right side of chart, flour, grits, cornmeal), although of course, rapid jiggles in supply always cause trouble.

    You know I’m a big fan of EROEI analysis … but at some point, it doesn’t matter very much to a farmer in the presence of (future) rising oil prices and then non-existence of oil:

    It takes a while to electrify everything, and 300HP combines aren’t easy, and in any case, cost $100K up, and you’re still paying yours off. Assume you’ve already leased 5% of your land to as a wind-turbine farm and electrified what you can. You still need Class-8 grain trucks to get your grain to the elevator. You need roads maintained. Railroads have to work. Fertilizer has to get to you.

    Now, oil prices soar:

    a) Devote some of your acreage to fuel crops, to get enough fuel to run the rest of your farm. Ignore the low EROEI.

    b) Sell your farm to somebody else, hopefully a developer, since the overall circumstances are not good for farmers.

    Having Iowa get out of farming entirely will *not* increase food supplies.

    Corn is popular because it has many uses; unlike, say miscanthus/switchgrass, you can decide what to plant at the beginning of the season, and when you harvest the corn, it’s a multi-use commodity. I’d guess, in practice, some places in Iowa will grow fuel crops, with appropriate local infrastructure. of course, some may well be better burnt for electricity than turned into transport fuel.

    Farmers grow whatever they think makes them more money within the various other constraints they work under. If they can’t run machinery, they *cannot* run farms that look anything like what’s there now. As oil prices rise, the prices of alternative fuels will rise as well, and the mix of food-vs-fuel will jiggle around. Right now, we “eat fossil fuels”…

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