Pimentel: Disses ethanol, but embraces “bioheat”


news conference was held on Saturday in the small farming community of Guelph, Ontario, to discuss the conclusions of a “ground-breaking scientific study” on the use of densified agri-fuels — such as switchgrass turned into pellets or briquettes– as a replacement for burning fossil fuels. The study was published in the journal Critical Reviews in Plant Sciences.

“The major advantages of producing densified warm-season grasses for bioheat include: it is the most efficient strategy to use marginal farmlands in the most temperate and tropical climates to collect solar radiation; it has an excellent energy balance; the feedstocks can be used conveniently in a variety of energy applications; and it is relatively environmentally friendly,” according to an abstract of the study. “Densified warm-season grass biofuels are poised to become a major global fuel source because they can meet some heating requirements at less cost than all other alternatives available today.”

Research firm Resource Efficient Agriculture Production, or REAP Canada, says the heat from burning these densified energy grasses and other agricultural residue “could produce the equivalent of 2.5 million barrels of oil per day by 2020 in North America.”

REAP Canada argues that using “bioheat” would be less costly and more effective, in terms of reducing greenhouse gas emissions, than pursuing mandates for ethanol and biodiesel content — such as the 5 per cent ethanol mandate supported by the new Conservative government. It also claims that it would be 25 per cent to 50 per cent cheaper than heating with oil or natural gas.

What’s interesting is that REAP Canada got Cornell’s David Pimentel to give a keynote address at the conference, where he apparently spoke publicly about his support for the emerging bioheat industry. In a press release before the conference, Pimentel is quoted as saying, “Bioheat offers the best energy and greenhouse gas balances of the available options and is the most efficient way to produce energy from farmland.”

Pimentel, as you’ll recall, is the chap who believes that ethanol and biodiesel production is a waste of time and money because, he asserts, it takes more energy to create the biofuels than the energy you get out of them. It’s an assertion that has been widely disputed. I unfortunately could not make it to the Guelph event to probe Pimental on this issue.

I have no doubt it takes less energy to simply compress switchgrass into briquettes and throw them in an oven to heat your house, but it doesn’t do much for the transportation market. Besides, does a bioheat market really have to take away from an ethanol market? If cellulose ethanol, for example, relies on agricultural residues such as cereal straw and corn stover, then this form of biofuel could still be produced for the transportation market alongside other bioheat-type fuels for heating.

In any event, it’s difficult to pass judgement without learning more. Stay tuned.

6 thoughts on “Pimentel: Disses ethanol, but embraces “bioheat””

  1. small farming community of Guelph, Ontario


    Guelph is a small city with a university and a lot of smaller factories and fabrication plants. Linamar, for instance, has a lot of smaller plants there — mostly serving the automotive industry.

    While there is plenty of agriculture nearby, the city is far from a farming community. Fergus, St. Jacobs or Arthur would qualify as small farming communities, but not Guelph.

  2. I would take care in lumping everything together as the “ethanol market”, then using the best example, cellulosic ethanol, to support your claims.

    A recent UC Berkeley meta study did conclude that grain ethanol was a sustainable fuel, i.e., an overall positive energy contribution of energy, but just so. They also stated an expectation that cellulosic ethanol would be much better, i.e., “The UC Berkeley team calculated a Net Energy Value (Output energy – Input energy) for corn ethanol of 4.5 MJ/Liter. Cellulosic ethanol fares much better, with a calculated Net Energy Value of 22.8 MJ/L.”

    Pimetel’s model was one of six studies that they analyzed and with which they took issue. Conversely, they also took issues with some overly optimistic studies, to which you may be referring when you state that Pimetel’s study is “widely disputed.”

    Unfortunately, much of this is based upon models rather than real world experience, Canada’s Iogen Corporation being one of the few exceptions.

  3. This argument about ‘requiring more energy to produce than what you get out’ is a compressed pellet of a diferent biological source. If there was a system that could produce more energy than it consumed, we’d have a leg up on perpetual motion machines. The net energy of these pellets, or any other fuel source, must take into account processing costs, which is the key factor being discussed assuming we can say that solar energy and Mother Nature provide the production costs of growing grasses. If compressing the pellets takes more energy than what we get back as heat, this is not a good fuel source – but it might be worse to use your own personal energy to haul bales of the stuff from the field in it’s raw, ‘uncompressed’ format because it won’t burn as cleanly. The black magic of oil is that geological processes have taken care of production, so we only need to wory about processing and transportation, whereas solar and wind are highly diffuse. Energy storage (energy density), however, may be more important than energy source (solar in this case) so these pellets may be a wiser method of heat storage than fossil fuels, especially if we got a dandy sol-ar-powered pellet-compressin’ mo-chine up in Guelph. Yee Haw! (no offense, lovely place).

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