Ew.

I know this is an oversimplification, but ethanol is a good alternative fuel because it's made from a renewable resource — corn — but it's not a good alternative fuel for the same reason.

But in Sweden, there's an alternative fuel derived from a renewable resource that doesn't have another use (beside being gross).

Yes, that's right, they've been using sewage waste.

From a story in the International Herald Tribune:

"Cars using biogas created a stir when they began to be rolled out on a large scale at the start of the decade. The tailpipe emissions are virtually odorless, the fuel is cheaper than gasoline and diesel, and the idea of recovering energy from toilet waste appealed to green-minded Swedes.

'When you're in the bathroom in the morning and you can see something good come of that, it's easy to be taken in by the idea - it's like a utopia,' said Andreas Kask, a business consultant who drives a taxi in Goteborg. 'But it hasn't worked out that well in reality.'"

Ford-owned Volvo had been making the cars, but said they would stop production to focus on cars powered by an ethanol/gasoline blend. But Mercedes and Volkswagen plan to introduce new biogas cars in Sweden this year.

Of course, biogas doesn't sound like it's a complete solution: from what the average person flushes down the toilet each year, it creates enough biogas to drive about 75 miles.