As I've said before in my blog, algae as biofuel is attractive.
Here's a proof of concept (shown on History Channel) that is using transparent tubes as bio-reactors collecting waste gas from a 1GW power station. It claims that 100% capture from the power station will need 2,000 acres of land or 8 square kilometers (2km x 4km).
The University of Kentucky is making making headlines on this. It's not new, but this is the direction we need to go in considering the 100-fold increase in photosynthetic performance.