Algae lamps save the world

There's a prize out there: The Virgin Earth Challenge -- which offers a prize of $25 million for a technology that removes a lot of CO₂ from the atmosphere, helping to defer the inevitable consequences of climate change.

Now I read about a lamp that grows microalgae. According to the blurb, one lamp could remove as much CO₂ as 150 to 200 trees, a ton of the greenhouse gas every year. If deployed widely, then it could have potential.

This lamp absorbs 150 times more CO₂ than a tree 

 This gets me thinking -- algae have to live, grow, and die. There would have to be a build-up of algal muck in these lamps. And algal muck can be made, fairly easily, into biodiesel. If commercial biodiesel from algae was already running, then the algal muck that would have to be cleaned regularly out of the lamps could supplement the commercially-grown supply. There would have to be collection trucks, but heck, there are trucks now that clean out Porta-Potties and trucks that collect used cooking oil. What's wrong with a biodiesel-fueled truck collecting the feedstock for more biodiesel?

This idea isn't entered in the Virgin Earth Challenge, but it should be. Motto: Green light for green life. (OK, I'll work on it.)