A.I.M. Interview: NASA's OMEGA Scientist Dr. Jonathan Trent

(Algae Industry Magazine) NASA scientist – the inventor, heart, and soul of the OMEGA system (Offshore Membrane Enclosures for Growing Algae) – Dr. Jonathan Trent received his PhD in biological oceanography at Scripps Institution of Oceanography. He went on to post graduate work in Europe studying the biochemistry and molecular biology of microorganisms living in geothermal hot springs, the so-called “extremophiles.”

...If you consider the scale of algae cultivation required to meet our current appetite for fuels and you put that in the context of the growing world population with food and water requirements, it is clear that whatever we do to make algae biofuels cannot compete with agriculture. For me this meant that we can’t use freshwater and we can’t use fertilizer, and in my view we can’t even use land. I don’t buy the argument about using the so-called non-arable land for algae cultivation, because if we made all the effort of transporting water and fertilizer to non-arable land to grow algae, why wouldn’t we make it arable land and start growing food on it?

I suppose if we were pumping seawater to the non-arable land it would be another story, but in general pumping water is energy intensive and not cost effective.

...I think the fact that in all our coastal cities we already have the infrastructure for “disposing” of our wastewater offshore, we need to consider the possiblity of using this wasted water and the existing infrastructure for growing microalgae offshore. In addition to using wastewater from existing offshore outfalls for developing algae systems, there are other good reasons for OMEGA, I mean float photobioreactors (PBRs) in seawater. For example, there’s the heat-capacity of the seawater that can be used to control the temperature of the PBRs –temperature control of PBRs on land is a huge and expensive problem. The sea provides other energy savings also. Wave action can be used for mixing and the salt gradient can be used for forward osmosis, which not only cleans the wastewater released into the sea, it also concentrates the algae for harvesting.

If the freshwater algae cultivated in wastewater escape into the surrounding seawater they die (freshwater algae can’t survive in salt water), which means they will not become invasive species in our coastal waters. The OMEGA structure itself can be used as an enormous substrate for developing aquaculture to grow edible seaweeds, mussels, oysters, or some other marine “crop” appropriate for the local conditions.

If you see where this is going, OMEGA is a system of systems or an “ecology of technologies” – in which the concept of waste disappears: a waste product from one part of the system becomes a resource for another part. As far as possible the whole system, which includes the environment, is in balance.

...Many of us in the algae community agree that we have to use wastewater for large-scale algae cultivation so as not to compete with agriculture, but also to meet economic requirements. If you look at our major cities, the wastewater systems tend to be embedded in the city. Take San Francisco, for example. It’s about 45 square miles and there are three wastewater treatment plants. The plant at Hunters Point, handles 65 million gallons a day. If you tried to build ponds around the wastewater plant, you’d have to displace freeways and all kinds of infrastructure. Just to deal with five day retention time you need about 1200 to 1500 acres of ponds, and it has to be on level land, which is really hard to find near San Francisco.

On the other hand, if we were to somehow float algae photobioreactors in San Francisco Bay and use the wastewater currently pumped offshore, we would use less than one percent of the huge area of the Bay and in the worst case we would displace a few fishermen – actually we’d probably improve the fishing in the Bay.

...(T)he US should be investing the kind of money and brainpower that we invested in the Manhattan project and Apollo. The Manhattan project was an investment of something like $22 billion (in 2008 dollars) over a five year period. And the whole Apollo program was about $98 billion over 14 years. They were amazing government-funded programs that mobilized the best and the brightest, actually from all over the world to reach socially and scientifically important goals.

Given the importance of liquid fuels, not only to the transportation industry, but to so many aspects of our society, and considering both the limited availability (peak oil and the location of reserves) and desireability (environmental impacts and national security) of fossil fuels, it’s time we make the transition away from fossil fuel dependence. The fossil fuel industry is nearly 150 years old and it represents some $5 trillion a year in revenue. READ MORE and MORE (MIT Technology Review) and MORE (NASA) and MORE (NASA) and MORE (Future Science) Watch VIDEO and MORE (Algae Industry Magazine)