Our sunglasses can capture sunlight to
charge our iPhones. There’s a building out there
powered by algae. And now, growing algae on sewage could generate affordable biofuels.
To
make this work, you begin with a raceway. This isn't a track for
Formula One cars; instead, it’s a series of small artificial rivers
where waste water flows and algae is cultured. In those ponds is a
paddle wheel, which pushes the water about and mixes algae into the
waste water. The shallowness of the rivers encourages sunlight and helps
the algae grow. And that algae is pretty important, because it's what
gets turned into biofuel.