Ask MAKE is a monthly column where we answer your questions. Send your vexing conundrums on any aspect of making to askmake@makezine.com. If we don’t have the answer, we’ll scare up somebody who does.

Phil asks:

I’m curious to learn more about some of the good “DIY algae growing at home” web resources for family scale production of algae fuel. Are there any available kits or books about this yet? (I’d be looking to spend less than $2,500.)
This Stanford student’s YouTube video looks intriguing, although I don’t happen to have a spare centrifuge lying around.

Hi Phil,
As far as I can tell, making liquid fuel from an algae bioreactor does, in fact, require a centrifuge to extract the oils from the algae. However, you can harvest the algae and make solid fuel from it through a simple drying process, which could be used for home heating. But be aware that producing even a small amount of dry fuel requires a sizable amount of biomass. For example, according to Algae Lab “To grow 100g of Spirulina a day would take roughly 20 square meters, or 216 square feet. It would have to get plenty of sun.”

If you’d still like to explore your own algae bioreactor for either solid fuel or food (spirulina), there are a couple of ways to go. Michael Fischer, the Stanford student from the video you sent, shows how to create his setup on an Instructables page. Also, algal fuel guru Aaron Baum sells starter kits through his site Algae Lab. If you want a professional consultant for a larger system, I’d recommend contacting him.

If anyone has experience with algae bioreactors or has more information, please post in the comments.

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