For more than 15 years, Dr. Todd Griffith has been working to create an offshore turbine that makes wind energy in deep ocean water more accessible. “Our turbine is designed to make offshore wind power safe, efficient and affordable,” he said.

Inside Dr. Todd Griffith’s laboratory stands a 6-foot-tall wind turbine that looks like an upside-down eggbeater; it’s actually a small-scale prototype for a radically different type of offshore wind turbine.

Griffith and his team of University of Texas at Dallas researchers recently demonstrated through extensive testing that the prototype works. More than 15 years in the making, the design shows promise for capturing untapped potential energy from wind blowing across deep ocean water.

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Learn more about how researchers in the Wind Energy Center at UTD are working to advance wind energy science and engineering in this YouTube video.

The next step is to build and test the design on a larger scale, as high as 500 feet tall. Ultimately, the offshore turbine would stand up to 900 feet tall, about the height of a 72-story skyscraper, and generate electricity from winds over the deep ocean miles from the coast and out of view from land.

This work is important for enabling energy independence and reliability for Texas, Griffith said. Texas, which has made it a priority to increase the capacity of the electricity grid, has been a leader in wind energy production.

“In the U.S., we have a major opportunity to develop offshore wind energy systems that can enhance energy capacity to the power grid in coastal areas,” said Griffith, professor of mechanical engineering in the Erik Jonsson School of Engineering and Computer Science. “To access wind energy in deep ocean water, however, we need a different solution. Our turbine is designed to make offshore wind power safe, efficient and affordable.”

Griffith recently received a $4.42 million research grant from the U.S. Department of Energy to move the project forward, extending a $3.3 million grant awarded in 2019 for a total investment of $7.72 million. The Advanced Research Projects Agency-Energy (ARPA-E) award is part of the Aerodynamic Turbines, Lighter and Afloat, with Nautical Technologies and Integrated Servo-control (ATLANTIS) program, which is aimed at developing new and potentially disruptive innovations in floating offshore technology. The research is not tied to any existing offshore wind energy farms.

The offshore wind turbine project is one of several research initiatives based in the Wind Energy Center, or UTD Wind, which is dedicated to the advancement of wind energy science and engineering. In addition to conducting research, UTD Wind provides opportunities to train future wind energy experts, including a growing number of students interested in the energy industry.

Griffith, who joined UTD in 2017, began investigating vertical-axis wind turbine designs in 2009 when he was a principal member of the technical staff and offshore technical lead at Sandia National Laboratories’ Wind Energy Technologies Department.

Researchers tested their prototype at the University of Maine, which has a facility that can simulate wind and wave conditions.

Griffith’s design has a vertical axis of rotation, which differs from traditional three-blade horizontal-axis turbines. The turbine sits on a platform partly above and partly below the ocean’s surface and is attached to the sea floor with cables. Unlike a traditional turbine design, the generator and controls are at the water level in the platform, providing greater stability and facilitating maintenance. A cable along the sea floor delivers electricity to land.

The turbine’s lightweight design, made with composite materials, is one of the keys to the structure’s success. The 6-foot-tall prototype, for example, weighs just 10 pounds. When wind pushes against the blades, they rotate to create a twisting force, or torque, that generates electricity.

Researchers are developing innovative features to ensure the design’s safety.

“We’re developing a new safety system so that in high-wind conditions, the turbine doesn’t topple over or spin out of control,” said Griffith, who is also deputy director of UTD Wind. “We’re creating a system that limits how fast the machine can spin and that can bring the turbine to a stop if necessary.”

The project includes collaborations with other universities. UTD researchers tested the prototype at the University of Maine, which has a research facility that can simulate wind and wave conditions. The researchers also have tested and will continue to test their design in UT Dallas’ wind tunnel, the Boundary Layer and Subsonic Wind Tunnel.

The project demonstrates the role UTD Wind can play in the innovation of the energy industry, said Dr. Mario Rotea, director of UTD Wind and professor of mechanical engineering. The grants will continue to support student researchers, some of whom have gone on to work in the wind energy industry.

“This investment from ARPA-E makes it possible for us to build and test a design that investors might consider too risky,” said Rotea, an expert in control systems and a collaborator on the offshore turbine project.

From left: Dr. Todd Griffith and mechanical engineering students Md. Sanower Hossain and Dan Bouzolin conducted tests of the offshore wind turbine design at a research facility at the University of Maine. The next step is to build and test the design on a larger scale, as high as 500 feet tall.