The Spanish region of Valencia famous for its oranges is doing something a little different with its left over orange waste. Seems they have found a way to take orange peel and pulp left over from orange juice creation and make ethanol out of it.

“We have a car plant … and we have the oranges,” Esteban Gonzalez, head of planning and housing for the regional government, told a conference on climate change.

The region grows 4 million tons of oranges a year and its existing five juice plants produce 240,000 tons of waste that could be turned into ethanol.

With another new juice plant planned, waste output will rise to 500,000 tons, Gonzalez said.

“Experience in California shows that would be enough to produce 37.5 million litres (9.75 million gallons) of bioethanol,” he added.
(via)

This leads to other wonderful ideas, cheese factories making energy from left over curd, furniture factories using wood chips to create energy, paper mills using left over pulp, there are hundreds of examples of industry that has a waste stream that can be turned into an energy production stream.