Mechanical and Civil Engineering Seminar

Although the United States has the second largest exclusive economic zone in the world, the resources afforded by our nation's oceans are vastly underutilized. In this seminar, I will discuss design methods and optimization tools that may enable increased, sustainable use of the oceans as a means to provide water, energy, food, and minerals for a growing population. The offshore systems I describe employ symbiotic designs, which facilitate reductions in overall system cost and increase system value by leveraging strengths of multiple technologies that can share common structural components and maintenance schedules.

Mineral extraction from the oceans, where critical elements exist in larger supply than on land, offers an alternative to land-based mining and a solution to the problem of limited terrestrial supply. I will present a symbiotic system that integrates a mineral harvester with an existing offshore wind turbine, an approach that increases efficiency, reduces environmental impact, and decreases mineral production cost. In the case of seawater uranium extraction, I will detail tools that optimize both the system design and deployment locations, which ultimately result in cost reductions of over 30% – making seawater uranium harvesting cost-competitive with breeder reactors.

Further applications of symbiotic offshore systems can yield solutions to problems in the water-energy-food nexus. For example, cobalt, a mineral that may be the limiting factor to large-scale lithium-ion battery production, could be harvested from the Gulf of Mexico using symbiotic systems in enough supply to meet over 27% of the nation's 2017 cobalt consumption. Symbiotic offshore systems can also allow pumped-storage hydropower to be integrated with reverse osmosis for combined grid-scale energy storage and freshwater production. Additionally, increased food production can be achieved through renewably powered offshore aquaculture systems employing symbiotic designs.