My presentation is tomorrow, but I have sat through some very interesting presentations over the past couple of days here at the Pacific Rim Summit on Industrial Biotechnology and Bioenergy. They have five panels going at once, but I have been sitting in on the cellulosic ethanol, algal fuel, and biomass logistics sessions for the most part. They will have links up to the presentations at some point, but I have been taking a lot of notes (12 pages of notes so far!)
On algae, these were some of the more pessimistic comments from various presenters, some of whom are executives at algae companies:
“Algae carries a great deal of technical risk.”
Asked about expected cost of algal oil: “I don’t know, because we don’t have any plants.”
“Photobioreactors (PBRs) are not a smart way to make algal fuel.”
“To scrub the emissions from a coal-fired power plant would require 35,000 acres of PBRs at a cost of $5 million per acre. But we might be able to get that down to $1 million per acre.”
“I calculate that it will take 36,000 acres of PBRs to scrub a power plant. The bottom line for those who would propose to use algae in this way? Abandon all hope.” – comment from the next presenter
“ExxonMobil is investing in algae but they said it would take 10 years to figure out if it was going to work.”
“Based on the absolute maximum solar capture at the equator, the theoretical maximum production of algal oil at the equator is 17,486 gallons per acre per year. The reality in Honolulu is about 833 gallons per acre per year. The energy balance – even with very optimistic assumptions and not including all of the unit operations – is well below 1.7 units out per unit in.”
“25 gallons of water is consumed per gallon of algal oil produced.”
“Algal oils are not economically viable.”
Now in fairness, these were comments of various presenters and some of the audience members took exception to some of the comments. One person commented that the water usage from corn ethanol when the corn has to be irrigated is much higher. Someone else pointed out that these comments did not apply to the fermentation approaches.
Incidentally, as a science project my oldest son is growing Spirulina at home under different conditions. We are also attempting to extract oil from some Haematococcus samples that we have. As a science project, I think this is fine (although it is more difficult than you might imagine). But nobody here seems to be too optimistic about algal fuels in either open ponds or PBRs anytime soon. I think the jury is still out on the fermentation approaches such as what Solazyme is working on.