Without the fiber and the mineral content of that stalk fiber the soils become quickly depleted.

FORBES: Breakthrough in Biofuels? Maybe.

And those reserves are quickly depleted in a panic.

FORBES: Dollarize Emerging Markets

Renault is particularly keen to promote fast-charging stations, along with exchange centres on motorways where depleted batteries can be quickly swapped for another one during long journeys. (This approach is being championed by Better Place, a start-up which has developed robots to handle the battery-swapping process.) Meanwhile the tinkerers are already at work: some are planning to build small, petrol-powered generators which can be towed behind battery-only cars on long trips.

ECONOMIST: Rational consumer