Luciano Medrano, via Facebook asked:
What are the disadvantages of algal biodiesel? Cant the big pools get weeds or pests?
Mark - If weíre talking about the photobioreactors that I'm thinking of, the ones that use sunlight and purple bacteria, those systems have been tested outdoors in sunlight and run for very long periods. Simply because they're natural species they're robust - they're not special genetically engineered ones that require careful conditions - the conditions in the reactor suit that kind of organism, and the metabolism that they live by produces hydrogen. So there's no reason for anything to take over and itís unlikely to happen. Itís certainly true that it's an issue in algal oil production, especially when you're thinking about open ponds which are open to the atmosphere where anything can blow in. That research field has to prove that their culture is going to remain pure enough and stable enough - they've been doing it for many years and itís looking very promising.