We had three aims in learning to make biodiesel and ethanol:
Both biodiesel and ethanol are
clean, grow-your-own fuels that can be made on-site in small villages from
renewable, locally available resources, for the most part using simple equipment
that a village blacksmith can make and maintain.
These fuels are among a wide range of sustainable rural energy options. Others are methane (biogas) digesters that turn livestock and crop wastes into cooking and heating gas, solar energy (see Solar box cookers), wood gas, charcoal and fuelwood (good fuels unless overharvesting destroys the trees themselves), wind power, water power.
Usually the "answer" is in a mix of technologies. Biofuels can be used to power small-scale farm and workshop machinery and electricity generators as well as local vehicles. Knowing how to make them provides a useful set of ecological questions in investigating local energy options which makes it more than worthwhile even if the final answer is "No".
For instance, should a crop such as peanuts be used to make fuel, or would the villagers be better off eating the peanuts? Or selling them? Or should they press them to make oil, for cooking or for selling, and feed the high-protein residue "cake" to livestock, which in turn they can either eat or sell, while using the livestock wastes (and the crop wastes) to make compost to renew the soil, or to generate biogas for cooking and heating? (The heat generated by the composting process can also be harnessed for heating.) Or should they grow a different crop altogether?
Should a grain crop be distilled to make ethanol fuel or should the villagers eat the grain? If they use the grain for livestock feed, it can be used for ethanol and still feed the livestock: the distillation process to produce ethanol converts the carbohydrates in the grain while leaving the protein. The protein residue is excellent stockfeed, which can be supplemented by forage crops which humans can't eat. This could mean improved utilization of the available resources.
This is the sort of question we'll have to find answers for in our work in rural villages. As always, it will be the villagers' views that decide the issue.
Foundation for Alternative Energy, Slovakia -- a good summary of the various ways to derive useful energy from biomass (34,000-word article):
A common objection to biomass
energy production is that it could divert agricultural production away from food
crops in a hungry world -- even leading to mass starvation in the poor
True or not? Not true: at best it's an oversimplification of a complex issue. It just doesn't work that way, and neither does hunger.