waThe green energy revolution was supposed to have arrived by now. That's what we were promised back in the 1970s or so by the Whole Earth Catalog and other friends of sustainable development. Renewable energy gets sidetracked whenever wishful thinking and pipe dreams distract public policymakers from the most promising technologies. Algae-based biofuels may or may not be one of those promising technologies, depending on where and how it's produced.
Mainstream scientific thought endorses algae-based biofuels but with realistic expectations. People who've done the math know that replacing a small portion of America's liquid fuel would require devoting enormous amounts of farmland to algae crops with very low yields. This does not mean algae-based biofuel should never be produced under any circumstances. It means there is a niche somewhere for limited production that doesn't crowd out food crops. Seaweed-based biofuel may avoid a food vs. energy tradeoff.
People who haven't done research take the easy way out and seek government subsidies. The algae-fuel industry is pushing for federal tax incentives that will put it on the same footing as the ethanol industry. That is very premature and probably a poor use of public money. Ethanol is a controversial energy source because it does not always produce a positive EROEI. Factoring in energy used in fertiliser added to crops gives ethanol a negative EROEI. Growing it organically gives it a positive EROEI but, like all things organic, limits the yield. Algae-based fuel must not fall into the same trap if it is to be viable.