For those who wonder what CO2-to-algae looks like close up, there was a demonstration system at this week's Burning Man festival.

New uses for old colostomy bags?

The Chlorophyll Collective [1]—a loose affiliation of scientists and industry types that's trying to assemble algae information, Unix "open source"-style—assembled the demonstration to take the exhaust discharge from an electrical generator at Burning Man and use it to foster the growth of algae.

How did it work? Well, no harvest-worthy quantities were ever observed in the system. Either the algae never reached any significant mass, or they were indeed harvested before we saw 'em.

Also worthy of note: while that was supposed to be generator exhaust bubbling through the bags, no generator could be found nearby, nor were any residual exhaust fumes detected.

What was that bubbling through the green garden hoses?

Chlorophyll Collective algae impresario Dr. Aaron Wolf Baum, AKA "Dr. Friendly", wrote us to clarify that the system was indeed functional.

"We were feeding the algae exhaust from a gasoline generator (visible in the photo you took as the red thing behind the plexiglass panel on the left edge of the photo), although not continuously," he said.

"Our maintenance of the piece was severely disrupted by the premature burning of the Man [2]. Also, our blower was having overheating issues (which we ultimately were able to solve), so the genny was generally turned off when we didn't have Collective members around to mind the store."

"I am an algae enthusiast but not an algae huckster. There are altogether too many of those out there already," he said, obliquely referring, no doubt, to organizations like this [3] (see the first story, biofuel from algae: organized grime?)

Also of interest from Burning Man: how much is a ton of carbon?

Big shoes leave big footprints.

An enterprising artist put a name and a face on the ethereal ton-of-carbon, creating the large 3D shoe, above, (carbon footprint, get it?) filled with one ton of charcoal.

The display was a clever, and intimidating, illustration of just how much matter a single ton of carbon represents.

Read more from the front lines of cleantech at Burning Man this year in our feature Partying to biodiesel [4].