What he has designed is a basic proof of concept. While I highly doubt he has a + EROI with this setup, he has an idea which possibly could be done on a larger scale, likely getting more efficient with higher volumes. Not a solution for our much more simple problem of overpopulation, but perhaps a good way to reduce our impacts, while offering us the opportunity to chat knowledgeably on the inter-webs.
This was on tomrrow's world in 1992. Using a giant coil of transparent tube they grew algae in it, dried it and then fueled a diesel (I think) engine. There was also a brief example of it being squirted through a naked flame and my did it burn! Sadly it's yet to be seen in viably large quantities, but cool tech. all the same.
Yes, there are hurdles to overcome, but it's an interesting field to pursue.