It has been known for decades that algae, in particular microalgae, have the potential to be used as a sustainable, carbon-neutral source of biofuels.1 From 1978-1996 the US Department of Energy (DOE) investigated the use of microalgae as a source of oil as well as biomass, hydrogen, hydrocarbons, alcohols, carbohydrates, methane, and syngas. This DOE algae program (The Aquatic Species Program) ended in 1996 for three reasons: 1) the DOE predicted that the cost of petroleum would remain relatively flat for at least 20 years (1996-2016), 2) that algal biodiesel could not compete with such cheap petroleum prices supported by a highly subsidized corporate infrastructure, and 3) there were many formidable technical challenges associated with growing the large quantities of algae needed for fuels. DOE was wrong about their predicted price of oil (Fig. 1).
Within three years the price of oil began to rise and within ten years it was >5 times the “flat” value the DOE had predicted. By 2009, the global reserves of petroleum are reaching their previously predicted limits,2 the largest remaining reserves of oil remain in politically unstable countries, and, most importantly, the increased burning of petroleum, impacting global climate, is of growing concern.3 Indeed, all things considered the price (in many senses) for the continued use of petroleum is too high. DOE’s prediction about the “price” of petroleum was wrong, could they also have been wrong about the economic and technical challenges preventing algae from becoming the much-needed replacement for petroleum? Considerable efforts are now underway to determine if algae can indeed be cultivated in sufficient quantities and at prices that are relevant for biofuels. Nearly all of these efforts are focused on scaling and improving traditional algae cultivation methods on land, which use shallow ponds (raceways) or large photo-bioreactors (PBRs). There are some non-traditional efforts looking into growing and harvesting algae in natural lakes and in harvesting algae directly from the ocean. Progress is being made, but to date, none of these systems have demonstrated they will be able to reach the quantities. and economics-of-scale for algae to contribute significantly to biofuels. In addition, most of the landbased methods are problematic because they significantly impact the environment--changing natural ecologies and competing for agricultural land and water. Indeed, the amount of freshwater required for replacing evaporated water in raceways and for controlling temperature in closed bioreactors, is in itself prohibitive. The goals of the Wind, Sea, and Algae workshop were to address the problems of large-scale algae cultivation on land by considering the possibilities of moving algae cultivation offshore into the ocean. More specifically, a multidisciplinary group of scientists and engineers from Universities, National Laboratories, and Industry, explored the idea of Offshore Membrane Enclosures for Growing Algae (OMEGA). Participants included experts on macro-algae (seaweeds), who provided background information from their offshore cultivation methods. We considered possibilities for ocean environments in general, and Lolland or more specifically the wind farms off the coast of Lolland, in particular. The program of the three-day workshop included lectures in the morning and breakout sessions in the afternoons. The groups discussed and debated, if offshore microalgae production is feasible, scalable, environmentally acceptable, and cost effective. Both the lectures and the breakout sessions were videotaped. This report includes transcripts of the lectures and discussions, selected and edited by the organizers. We hope this volume will help elucidate the challenges and opportunities of offshore algae cultivation and provide inspiration and guidance for future developments in this field in Lolland’s community test facility and beyond.