Eco Factor: Photo-bioreactor made from recycled water bottles.
Using algae to develop biofuel is not a new thing, and researchers have previously made some bioreactors in which the process takes place. However, a new demonstration at Instructables does show how one can make an algae bioreactor using nothing other than recycled plastic bottles. The photo-bioreactor uses algae to convert carbon dioxide and sunlight into energy, which is produced in the form of algae biomass. This biomass is extracted and used to develop carbon neutral biofuel. Head over to Instructables for the DIY details.