Stanford Energy Student Lectures - Offshore Wind Testing and Intermediate-band Solar Cells

Join us as grad student/postdoc speakers from various technical areas deliver short and accessible presentations about their innovative clean energy research. Learn more about cutting-edge science and the most recent breakthroughs in areas such as renewables, energy conversion materials and devices, catalysis, and decarbonization from the researchers themselves!

Refreshments will be provided starting at 2:45 pm. Share your feedback on the speakers for a chance to win a Coupa gift card!

 

Speaker Topics:

Yun Ni - A Robotic Approach for Real-Time Hybrid Simulation of Floating Offshore Wind Turbines

Abstract:

Floating offshore wind turbines (FOWTs) offer a pathway to unlock deep-water renewable energy, yet full-scale controlled testing remains impractical and small-scale experiments suffer from similitude distortions. Real-time hybrid simulation (RTHS) overcomes this limitation by coupling physical hydrodynamic experiments with numerically simulated aerodynamic loads through actuators and sensors. In this study, a lightweight industrial robotic arm driven by electric servomotors was adopted in place of conventional hydraulic actuators, offering a compact footprint and improved force resolution in low-load regimes. A model-free adaptive force control strategy was implemented to emulate 6-DOF aerodynamic loading on a small-scale FOWT specimen. As physical testing is costly and the multi-dynamical system exhibits uncertainty under wave disturbances, we further developed a virtual RTHS platform that integrates the robotic arm, floating specimen, hydrodynamics, mooring dynamics, and a numerical aerodynamic model. This digital environment enables researchers to rapidly pre-tune controllers prior to physical deployment. Experimental results demonstrate that the proposed robotic actuation system achieves satisfactory performance under operational wave conditions. Both the actuation system and virtual RTHS platform advance RTHS testing capabilities for FOWT, establishing a more viable tool for FOWT design validation and reducing the cost required to bring next-generation floating wind technology to the global grid.

Speaker bio:

Yun Ni is a fourth-year PhD candidate in Civil Engineering at Stanford University, where her research focuses on real-time hybrid simulation (RTHS) to enable cost-effective validation of next-generation renewable energy systems. Her work is highly multidisciplinary, bridging structural engineering, ocean engineering, robotics, and real-time control systems to accelerate the deployment of offshore wind and marine energy infrastructure. Prior to her doctoral studies, she earned her bachelor’s degree in Civil Engineering from the University of Canterbury and spent three years as a geotechnical engineer at Tonkin + Taylor, an environmental and engineering consultancy, in New Zealand. She is dedicated to advancing environmental sustainability and developing innovative, cross-disciplinary engineering solutions for resilient energy infrastructure.

 

Zhiqiao (Kate) Jiang - Two-Step Photon Absorbers for Obtaining High Solar-Cell Voltages with Low-Energy Photons

Abstract:

Expected to make up 50% of global renewable energy generation by 2030, solar cells are one of the most important sustainable pathways to produce clean electricity. Over the past decades, scientists have worked on improving solar-cell efficiencies while lowering production costs. Nevertheless, most of the high-efficiency solar cells require complicated designs and elevated costs. Solar-cell light absorbers that are designed to produce a high voltage in a device by harvesting blue light, waste the low-energy light (e.g., infrared light) that comprises much of the solar spectrum. Likewise, solar-cell absorbers that can use this low-energy light, cannot produce the high voltages we need. This talk presents a type of solar-cell absorber that can simultaneously harvest both ends of the solar spectrum to deliver high voltage and high efficiency. This solar cell architecture, called an intermediate band solar cell (IBSC), is achieved by introducing an intermediate energy band in an expanded 3D halide perovskite analog. Compared to other IBSCs that rely on sophisticated fabrication processes, our solar cells can be fabricated with low-cost solution-based methods that are already implemented in industry. We thus present a potentially lower-cost and higher-efficiency new IBSC design for the solar-cell community to produce useful electricity from otherwise wasted light.

Speaker bio:

Zhiqiao (Kate) Jiang is a fourth-year Ph.D. candidate in Materials Science and Engineering advised by Prof. Hema Karunadasa. Her research focuses on studying optoelectronic properties of halide perovskites and engineering semiconductor band structure for efficient solar-cell devices. Kate obtained her bachelor’s degrees in Chemistry as well as Materials Science and Engineering from the University of Pennsylvania through the Vagelos Integrated Program in Energy Research. Under the guidance of Prof. Chris Murray, her research focused on the synthesis and self-assembly of semiconducting nanoparticles.