STTR Phase I: Modular Tidal Energy Systems for Power Generation in Remote Coastal Communities

The broader/commercial impact of this Small Business Technology Transfer (STTR) Phase I project is to enable remote coastal communities to lower their electricity rates by providing them with a locally deployable marine energy technology that harnesses energy from ocean tidal currents. Many coastal communities in the United States lack reliable access to grid electricity and instead rely on diesel generators that are expensive to operate logistically due to the need for constant resupply of fuel. This project supports the development of a modular energy system that captures the predictable motion of tidal currents to produce emission-free and reliable electricity. If successful, this innovation could provide a more affordable and more resilient source of electricity than diesel generators for many communities across Alaska and other coastal regions around the world. This project also has the potential to create high-skill jobs in engineering, manufacturing, and utility operations upon scale-up and broad adoption. The technology aligns with the National Science Foundation's mission to advance science and promote the progress of science for societal benefit and economic growth. Its long-term commercial potential could support domestic job creation and tax revenue by developing a new industry centered on modular scalable marine energy systems. The intellectual merit of this STTR project lies in the development of a novel power take-off system for the company's modular tidal energy technology. One core technical innovation is the use of a drag-based shrouded rotor, which minimizes material usage while maximizing structural rigidity. The rotor also has the property of shedding thrust force as rotational tip speed increases, which could allow for drag-based rotors to operate in higher-velocity currents while shedding the high thrust forces. An issue with designing a power control system around this rotor is this requirement that the rotor operates at a low rotational speed with high torque - a unique challenge for small-scale systems because voltage must be raised above battery voltage. This requires either (1) a high gear ratio gearbox or (2) a boost-type circuit. Both approaches are generally more expensive, which is a challenge for commercialization. The shaft seal also adds significant parasitic torque and must be optimized to accommodate dynamic forces in demanding marine environment. The goal of this Phase I project is to design a system capable of charging a battery in off-grid environments with a robust power controller. If successful, this work will help build the foundation of knowledge around drag-based rotors for power generation, supporting a path toward full commercialization in coastal communities. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.