Cristina Archer, associate professor of physical
ocean science and engineering (POSE) and geography
Photo by Lisa Tossey
Cristina Archer would like to see kite technology reach a whole new level.
She is not talking about children’s toys. She means airborne wind turbines – or machines that can capture energy from strong winds thousands of feet off the ground, suspended in the air by tethers.
Very, very strong tethers.
“They have to be incredibly strong,” said Archer, who joined UD’s College of Earth, Ocean, and Environment earlier this year as associate professor of physical ocean science and engineering and associate professor of geography. “It’s a materials engineering issue.”
Startup companies are working to overcome this and other challenges, having already demonstrated with prototypes that the high-flying devices can transmit clean, renewable energy back down to Earth. Some of the designs build on concepts outlined by Miles L. Loyd on crosswind kite power, showing that kite components can move faster than the wind around them because of the way different forces interact.
Archer, for her part, studies how much wind there is at both the extreme heights needed for airborne wind turbines and much closer to the ground for conventional wind turbines. Using numerical modeling and field research, she examines how wind capacity and speeds change with altitude over the entire planet.
While Archer’s work is applicable to renewable energy applications, it is grounded in her interest and expertise in meteorology.
“Basically I’m a meteorologist and an engineer, and so wind power is a natural merge of the two,” Archer said. “I look at technologies of energy from a meteorological point-of-view.”
Archer grew up in Italy with a passion for environmental issues and curiosity about the weather, but she saw meteorology as a field for men: At that time Italian weather forecasters were primarily military men, broadcasting their reports on television in uniform. Archer instead decided to earn a master’s degree in civil and environmental engineering from Politecnico di Milano.
By chance she met an American professor who encouraged her to study meteorology in the United States. She completed a master’s degree in meteorology at San Jose State University and a doctorate in civil and environmental engineering at Stanford University.
While working on her postdoc at the Carnegie Institution for Science, Archer studied the jet streams in relation to climate change to see if they were changing at a global scale. She found changes in the position, altitude and intensity of jet streams, with them moving toward the poles and to higher altitudes.
“Once I started to look at high-altitude jet streams, it was natural then to focus on airborne wind energy,” Archer said.
Most recently she was an assistant professor at California State University, Chico, and came to UD in January as part of a six-faculty member cluster hire in the environmental sciences. Currently she is looking at issues surrounding what happens when kinetic energy is extracted from the wind. She is quantifying the impact with an observation-based approach, then simplified into a climate model.
Archer also continues to help increase awareness about the potential of wind energy. While onshore wind energy is already in use and offshore wind farms in the United States are in the planning stages, airborne wind energy is still taking off. Archer organized a conference in 2009 to bring competing airborne wind energy companies together to address policy issues and work together to present information about the technology to the public.
“People think of kites as toys, and now all of the sudden we are saying that you can make energy off of them,” Archer said. “It’s not obvious, and that’s the beauty of it.”