APPLES, ORANGES, SUGARCANE AND CORN

Milton Maciel speaks with the authority of a former government official who served as Secretary of Agriculture in Brazil’s northeastern state of Alagoas, one of Brazil’s main ethanol-producing regions.

ETHANOL, OIL AND EROEI

Milton Maciel

From Brazil

Relevant links:
http://www.solovivo.com/

http://www.evworld.com/view.cfm?section=article&storyid=1107

The standard method for evaluating net energy of an energy resource is the measure known as EROEI, meaning Energy Returned On Energy Invested. If this number is larger than one, then we a have an energy source. If EROEI is lesser than one, then we have an energy sink.

One of the most controversial issues now is the figure for EROEI for ethanol. As corn ethanol EROEI is so low (1.3 : 1), in USA, there is in this country a general trend to nail sugar cane ethanol in the same coffin. However, this is a problem specific with corn and its conventional agrochemical cultivation, less efficient than sugar cane cultivation under the ideal conditions it finds in Brazil tropical land, where it is grown rain fed, avoiding the use of expensive and water depleting irrigation.

Sugar cane ethanol EROEI, under correct technologies, is much higher than that for corn ethanol.

Its minimum figure of 8.3 : 1 (as of 2001) is now already outdated, even for conventional cane cultivation, in Brazil. Not only in cultivation technologies, but also in industrial distillation processes, further advancements were achieved. The new study we’re preparing for publication now shows considerable higher results for 2007 and an at least 20% increase in EROEI figures in the coming two years. This holds for conventional chemical sugar cane. When we apply figures to organic sugar cane, EROEI has a potential for further increasing, theoretical limit being as much as 50% higher.

With an average yield (5 years) of 85 tons/hectare of cane stalks in south/center region, for conventional chemical cultivation, and an average of 85 liters of ethanol produced from each ton of cane stalks, we have an average production of 7225 liters of ethanol per hectare. (1 hectare = 2.47 acres)

With an average (9 years, least case) of 109 tons/hectare of cane stalks in the same region (where 85% of all Brazil’s sugar cane is produced) for organic cultivation and the same industrial average of 85 liters of ethanol per ton of stalks, we have an average of 9265 liters of ethanol per hectare.

As a comparison, corn ethanol production, for an average high yield of 150 bushels/acre in corn grain, is 400 gallons/acre, the equivalent of 3750 liters/hectare.

Why is sugar cane so more efficient?

First is the reality that sugar cane is just a rude perennial grass that is farmed as a semi-perennial culture, while corn is an annual culture, one that must be sown every year, with the corresponding expenses in seeds, energy, fertilizers and soil movement, plus a more intense schedule of pesticides use.

Under conventional cultivation, sugar cane in Brazil it is the large culture that is less chemicals dependent, consuming annually less than 20% of the fertilizers and pesticides consumed by soybeans, for instance. The conventional culture, once planted, is kept producing for 5 to 6 years and, only then, is renewed. Organic cane areas are subject to renewing only each 9 to 18 years, with considerably higher yields. Furthermore, total area dedicated to sugar cane in Brazil, devoted to ethanol production, is still less than 1% of total culture and pasture available land.

Incidentally, I think the same organic cultivation techniques we use in Brazil for sugar cane could be applied in Hawaii (USA), Australia, India and many other countries, with particular emphasis in some countries of Africa, the ones I believe may become the best bioenergy exporters for Europe and Asia (I’m just working on this subject now), the same way Latin America may become an important bioenergy partner for USA and Canada. In regions where exists temperature, fertility or water restraints, organic methodology can compensate much of the difficulties found with conventional chemical cultivation.

EROEI is not all

It is my particular position to think that we cannot place EROEI in a sacred unarguable position for evaluating alternative energies. It is evident that, by no means, an EROEI value smaller than one is a good thing. But, in some particular cases, maybe even that could be tolerated for some time. As an example, I recall that, at the very beginning of Brazil’s ethanol large scale production for oil substitution, after 1975, the alcohol cost of production was more than twice the cost we have today. Also, in the seventies, ethanol was heavily subsidized and today there isn’t any kind of subsidies for it. In 30 years a spectacular change occurred: from heavily subsidized to not at all subsidized and with a large cost reduction, because of important gains in both cultivation and industrial processes. Since then, more than a million direct jobs have been created and maintained and more than 100 billion dollars have been saved from being lost as oil imports.

We must also consider that sugar cane and sugar cane ethanol industry is one of the least capital intensive and one of the more fast industries to install. In one year you can plant cane and build a distillery, starting to operate it in less than 1.5 years since starting point.

EROEI and costs for oil

EROEI is important in evaluation of economical costs, but that may be a somewhat limited concept, because I think is not safe to consider EROEI independently of TOTAL costs. In other words, it doesn’t help if we have a good energy yielding source per se, as oil, maculated by a very negative record of indirect and hidden costs. These hidden costs are an important part of the EI factor (the denominator) and, like that, they cannot be dismissed.

When we think of costs, we cannot think of economic costs only. We must consider the environmental and the social costs too. So, as our standard reference for EROEI is oil, there are three points to consider:

1 – Oil EROEI has been falling constantly with time, as lighter oils are extracted first and remaining reserves include mostly oils that are heavier, deeper and more difficult to extract. From figures as large as perhaps 100:1 we are arriving to 10:1 and even lower relations. So oil EROEI is not uniformly a high value. On the contrary, it is on the verge of becoming itself a worthless figure very near to one for a very large number of wells and whole fields in plain depletion, demanding absurd energy inputs.

2 – On the matter of SOCIAL costs, oil has a terrible roll of costs – most of them related to military and wars for oil and gas. And, also, related to the tyranny of automobiles, coming end of suburbia, rising prices of food, etc. For instance, the REAL cost of oil, for the USA, is much higher than officially admitted. When we internalize the military costs of oil wars and intelligence, the real USA cost of a barrel of oil is higher 110 dollars, not only 60+ dollars as nominally priced at present moment.

3 – In terms of ENVIRONMENTAL costs, oil has an even more terrible record: that of global warming, the most adverse of all risks humanity is facing this century. Not to speak of diesel fumes, tire dust (from oil most loved junior, the car), acid rain, spills, groundwater contamination and related evils.

So, IMHO, I believe EROEI, being itself different from cost, cannot be evaluated as an independent entity. To consider EROEI for oil, our dubious standard for evaluation of other alternative energy sources, in a context that takes economic, social and environmental costs in consideration, results in a more realistic evaluation that favors biofuels of high EROEI – like sugar cane ethanol in Brazil – very much.

Milton Maciel in Brazil

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