Student Spotlight: Maximizing Wind Farm Power with Physics-based Models

MIT student Grace Harrington has been researching how physics-based computational models can help bridge the gap between academia and industry – with the goal of providing a better balance between analysis time and precision. Through the MCSC Climate & Sustainability Scholars Program, Grace had the opportunity to explore this topic, alongside the Howland Lab and Ph.D. student Kirby Heck, as she continues to understand and dive into various facets of climate and sustainability. Inspired by her Civil and Environmental Engineering major and Energy Studies minor, researching wind turbines caught Grace’s attention because this path allowed her to better understand one type of renewable energy infrastructure.

Grace’s interest in wind energy began before she came to MIT.

“I remember driving between Seattle and Spokane and passing trucks carrying large turbines blades. The scale of the operation was fascinating,” Grace said. “It is a cool opportunity to now learn more about the technology as part of my research.”

When it comes to that technology, in the wind energy sector and designing wind farms, physics-based models are used to understand the computational fluid dynamics involved in the wind turbines. In wind turbine arrays, the interaction of wakes on downwind turbines can result in a 10-20% loss in energy production across the entire wind farm. Thus, it is critical to be able to understand the interaction of wakes on downstream turbines since the amount of energy available to a singular turbine is proportional to the incoming velocity. These models help analyze the airflow around the blades of a turbine since it is not feasible to compute every single particle that moves around a single turbine blade and scale the data over time as the blades turn. Therefore, wind turbine research relies on simulations to capture as much detail as possible.

Throughout her time in the Scholars program, which allows students to work directly with faculty and principal investigators across MIT to develop their research projects focused on a large scope of sustainability topics, Grace’s research focused on changing wind turbine angles. She investigated how changing the angles of the turbines relative to the incoming wind (called yawning) could deflect turbine wakes away from downstream turbines, increasing power production across a farm. Her research helps provide confirmation that wind turbine operation can be adjusted to improve efficiencies.

Currently, the most precise models are Large Eddy Simulations (LES) but these also require hundreds of computational hours to analyze the behavior of just one turbine. In response to this lengthy process, the Howland Lab has developed a simpler model that requires less computational resources and aims to predict the behavior of a single turbine as well as the dynamics across a whole wind farm. These improvements are appealing to industry, as companies look to implement climate solutions quickly.

Through her own research and contributions to the project, Grace’s goal has been to help with calibrating this simpler model with the results of the more detailed and accurate LES simulation. This research is important because computationally less intensive models can be scaled more quickly and provide a larger grasp of the whole turbine array, which are otherwise impossible to model by the LES simulations. This simplified model addresses one major barrier between academia and industry: a difference in pacing. The project and research methodology aim to provide a pathway for the resulting academic research to make an industry impact by identifying useful trends and best practices at a rate that is more compatible with the industry timeline.

In order to capture the behavior of the interaction between the turbines and the wind, Grace applied the principles of fluid dynamics. Within these principles, however, there is flexibility in the decisions surrounding representing the velocity field of the wake, with common representations being the Jensen model (used in industry) and the Gaussian method (in mathematics, an algorithm for solving systems of linear equations). Grace’s research concluded that scaling up from the wake of one turbine to a full array requires additional considerations to capture a reasonable level of the wake behavior.

Unique to her project, Grace used stakeholder interviews to understand the pain points and constraints associated with implementing new technology, including yawning turbines. Interviewing both academic and industry perspectives allowed Grace to conclude that keeping the needs of industry in mind during the development of the model will shape the types of questions to explore, such as focusing on overall energy production, but also the format and usability of the model.

Grace observing a lecture during the classroom component of the Scholars Program.

One aspect of the MCSC Scholars Program that stood out to Grace was having the opportunity to learn more about the perspectives and approaches to climate themes.

“The program was very interdisciplinary; not just in that the students within the program were from all different majors, but also that the guest lecturers were from a wide range of disciplines,” Grace said.

Through guest lectures and hands-on experience, the MCSC Scholars Program provided an environment for Grace to explore different careers within the climate sphere. All of her conversations with researchers, PhD students, and industry stakeholders exposed her to the different ways she could continue to contribute to mitigating the impacts of the climate crisis.

“Originally I chose wind energy as it seemed like an obvious choice for my research project; however, throughout the class I was exposed to so many other areas that I had not even thought about,” said Grace. “Ultimately, it was reassuring to know that if I am passionate about sustainability, I will be able to incorporate it into any future career.”

Grace is currently a teaching assistant for an energy systems class, and she is excited to spend her last year at MIT continuing to explore her place within the climate sphere.