An Oversized Project Creates Oversized Opportunities for Graduate Students

Eric Loth is literally going to extreme lengths to cut the cost of wind energy in half. Loth, chair of the Department of Mechanical and Aerospace Engineering, is leading a team of researchers from four universities and two national labs to design an offshore wind turbine with blades that extend 200 meters. They are 2.5 times longer than any blades now in use.

Doctoral student Carlos Noyes became part of this unprecedented project even before the Department of Energy’s Advanced Research Project Agency - Energy (ARPA-E) awarded Loth and his colleagues $3.56 million to produce a prototype for the segmented, ultralight, morphing rotor (SUMR). As one of Loth’s graduate students, he helped write the grant proposal.

“Being part of this project has been an incredible opportunity for me,” Noyes said. “We are trying to design a turbine on a scale that has never been attempted before. If we are successful, it could have a huge effect on energy issues.”

Bigger Is Way Better

“If you want to decrease the cost of wind energy, you have to think big,” Loth said. “Every part of the design we are developing follows from that proposition.”

The reason that size matters reflects a combination of physics and atmospheric science. The longer the blade, the more energy it will capture. The higher the blade, the stronger the winds it will encounter.

A few simple calculations reveal the audaciousness of this concept—and explain Noyes’ excitement. Loth’s turbines will be among the tallest structures in the world. With a top-to-bottom rotor diameter of 400 meters suspended a 100 meters above the ground on a support tower, they will stand just 40 feet lower than One World Trade Center.

The benefits are similarly outsized. SUMR will be capable of generating 50 megawatts, ten times more than the current generation of wind turbines. That is enough electricity to power 11,000 homes.

An Outsized Technological Challenge

As Noyes points out, creating such a gargantuan structure requires more than making incremental improvements to existing designs. “We are rethinking everything,” he said. “Ideally, the design for each component will reinforce the design of the whole.”

Traditional turbine blades are rigid. As a result, the longer they are, the more reinforcement is required to allow them to withstand stresses from severe weather. This additional weight increases both their inertia and their cost. For inspiration, Loth turned to lightweight, flexible palm trees. His blades are segmented, connected by a series of joints that enable them to fold backward in heavy winds, like palm fronds in a storm.

Segmentation satisfies a number of other design requirements. It is currently impossible to manufacture, transport, or assemble a traditional 200-meter blade. Building the blade in sections clears away these obstacles.

Noyes is working on a number of technical challenges, including designing the hinge between the segments so that it can dynamically adjust the morphing angle of the blades. He is also creating a fairing, or deflector, for the tower that would prevent the wake of winds striking it from interfering with the rotor. To keep the blades from striking the tower when they morph, the rotor is affixed to its downwind side.

An Exceptionally Well-Rounded Education

Noyes said that like all engineering graduate students, he is “taking classes, writing research papers and trying to get published.” At the same time, he feels that the project is exposing him to a variety of nonengineering skills that are nonetheless critical for being an engineer.

Noyes points out that he is gaining experience working in multifunctional, decentralized teams. The staff of all six institutions in the project — the University of Virginia, University of Colorado, University of Illinois at Urbana-Champaign, Colorado School of Mines, Sandia National Laboratories and National Renewable Energy Laboratory — hold a virtual meeting every other week, while graduate students meet on alternate weeks.

“This project has assembled some of the leading experts in areas like aerodynamics and control,” Noyes said. “For it to remain on track, we all have to learn to communicate in ways that our counterparts can understand. This has been a learning experience.”

Noyes has also had the opportunity to present the project to members of the public. With Loth, fellow graduate student Meghan Kaminski and Daniel Zalkind, a graduate student from the University of Colorado, Noyes went to Capitol Hill to present the turbine research at the 2017 APRA-E Congressional Showcase. The SUMR team was one of only six groups selected for a special session for senators, representatives, energy committee staffers and other policy makers. “It was cool to speak to people who may have an influence on energy and environmental regulatory issues,” Noyes said.

Noyes believes that the range of opportunities he has had to grow professionally will serve him well when he completes his degree and goes on the job market.

“All the things I’m doing — the technical work on a cutting-edge project as well as writing proposals, attending the showcase and speaking at events — will help me in my career,” he said. “The breadth of my experience feels unusual for a graduate student.”