科学与发展网络(SciDev.Net)

Several questions need to be answered before doing any work on biofuels in Africa (see Biofuel: Africa's new oil?).

Is sufficient suitable quality land available for growing whatever crop is found suitable? I doubt it, as Brazil, like the United States, is blessed with large areas of arable land and low population densities.

Secondly what yields of oil/ethanol can be grown per hectare and how many hectares are needed to produce even one per cent of the annual oil consumption? I read about jatropha but who will fund the cost of establishing plantations — and where is the land — for 4–6 years before the first harvest? Will there be a net energy gain considering the quantity needed for harvesting, transporting, processing then moving biodiesel to the consumer?

Yield figures from tropical parts of Asia will not be replicated in semi-arid and arid parts of Africa. It is unlikely that sufficient surplus biomass can be grown to convert into biofuel but I hope I can be proved wrong.