A huge amount of R & D funding has gone into the development of alternative biofuels, in particular algae based biodiesel. Many great breakthroughs have been made as Sarah Backhouse reported earlier in the week when she met with the CEO of Original Oil.

But how green is algae really? A new report by the University of Virginia digs deep into the life cycle costs of producing algae fuels, and it doesn't look to good.

Is it dirtier than petroleum? No. The amount of CO2 emitted by the burning of algae oil is theoretically zero because the algae consumes CO2 as it grows. But the reality, scientists have found, is that algae oil is far from carbon neutral.

In order to efficiently produce algae stocks, a steady stream of fertilizer is required and that fertilizer is most commonly produced and distributed using petroleum products, and it emits large quantities of NOx (a potent greenhouse gas) into the atmosphere.

The solution? Piping in sewage as a fertilizer supply. This would result in a fuel that has a net CO2 uptake. 

via: e360 (Yale)

Is algae oil really a clean fuel?
There is a lot of hype around algae-based biofuel but is it that much better than petroleum? Or is it even possible without petroleum? UVA Study.