The Oil Drum

Thank's for this link. My brother in law is investigating for potential market applications in France exactly for this material. He claims 1 ha of rapeseed oil needs 50 liters of diesel to be completly worked from seeding to harvest and yields 2000 l of rapeseed oil. Waste of the process can be used for various applications like cow feeding.

I still have concerns for global EROEI, since most studies don't include all energy requirements like construction and maintenance of all the engines (ever seen how a wheel on a tractor is changed ?), irrigation (in our countryside water has to be pumped for irrigation. Water volume required has been increasing in the past years). Volumes of fertilizer and pesticides vary enormously from one published study to the other as do the estimated BTU's for the manufacturing of these products (see links provided by robert rapier for an estimation of these spreads).

And for the long term I keep asking my brother in law to please consider soil depletion (a very real issue, since plants do need other elements than N,P,K and CO2 to grow), surface of arable land (in slight excess in France but already competing with agriculture for food). Also don't forget that EROEI of our whole transportation system is <<1. This means that energy taken from biomass is taken out and isn't put back into the system except for CO2. For now there is an excess biomass with regard to the whole ecosystem, otherwise oil wouldn't have formed. So we can sacrifice some of this ... but at what ecological cost and in what places ? Moreover, if we increase the area of arable land, will we really increase the total biomass (i.e. the carbon sink) ? I stay with stuart staniford on this point, increasing our total C02 emission is probably very deleterious.

I must say that these arguments don't hold for someone involved in agriculture. In Europe biodiesel will increase, regardless of what we say or may think, unless the consequences become disastrous or the economy breaks down.