The snowy U.P.: Ideal for testing solar panels

It’s hard to imagine, even in the waning days of summer, but snow is coming. Lots of snow. 

The U.P.'s snowy climate makes the region an ideal location to test solar panels in winter conditions. Conventional wisdom says solar panels in extremely snowy climates aren’t a reliable source of alternative energy. But no one really knows how much snow impacts solar power systems or what to do about it.  

A researcher at Michigan Technological University in Houghton and her team are looking for answers to those questions.

Ana Dyreson“We want to understand snow’s effects on solar tracking systems,” says Ana Dyreson, an assistant professor of mechanical engineering-engineering mechanics. “Snow prevents solar from working. It’s heavy and can damage solar panels. But we don’t know how big an issue it is. That’s what we’re looking at.” 

Dyreson is investigating the impacts of climate and climate change on solar energy systems in the Great Lakes region. Her current research focuses on single-axis tracking systems, a technology that adjusts the position of a solar panel along a single axis to follow the sun's changing position throughout the day. Single-axis tracking can help address the snow problem because it sheds snow as it tilts to follow the sun, Dyreson explains. 

Her research is part of a project led by Sandia National Laboratories and funded by the U.S. Department of Energy Solar Energy Technologies office. Dyreson and her team are using energy analysis and grid-scale modeling to study the performance of renewable technologies in snowy conditions.

“Our research links power plant-level thermodynamic models, climate models, hydrology models and electricity grid operation models to understand how weather and climate change will impact future power systems,” she says. 

A regional test center

Dyreson is conducting her research at the U.S. Department of Energy’s Solar Energy Regional Test Center (RTC), a recently built Michigan Technological University facility operated by the university’s Advanced Power Systems Laboratory near the Houghton County Memorial Airport. Array Technologies of Albuquerque, New Mexico, supplied a 10-row, single-axis tracking solar system and continues to partner on the research.

So far, Dyreson and graduate students Ayush Chutani and Shelbie Davis have observed the single-axis tracking system at the RTC for one winter. They are now analyzing the data they collected. 

Their next step will be to share and publish their results. This coming winter they plan to use their data to develop a predictive model, create estimates of the impacts of heavy snow on solar grids and test ways to alter the single-axis tracking system to shed more snow. 

Under the technical oversight of Sandia National Laboratories, the RTC program is a consortium of five outdoor solar research sites across the U.S. that evaluate the performance and reliability of emerging photovoltaic technologies. 

Ana Dyreson in front of solar panels, without snow.

The RTC program gives U.S. solar companies access to these sites and to the technical expertise of Sandia and its academic partners, to drive both product innovation and commercialization of new high-efficiency solar products.

Dyreson started applying for research grants to fund her solar energy research in August 2021. 

Last December she was awarded a grant just shy of $500,000 from the Alfred P. Sloan Foundation for a project called “Electrification and Climate Resilience in the Rural North: Challenges and Opportunities.” It will enable her to identify social and technological challenges to resilient and equitable low-carbon electrification. And she’ll be seeking the most technically feasible and socially acceptable ways to electrify the energy sector while adapting electric power systems to climate change.  

Energy is fascinating

What intrigues Dyreson about energy research?

“Energy is something you can’t taste, see or touch, yet it powers our lives,” she says. “What magic.”  

From a young age, Dyreson was interested in how society manages energy.  
“Following one of my older sisters into engineering was an obvious way to explore this passion, which led me to mechanical engineering and work on renewable energy and electric power systems,” she says.

Graduate students explore new approaches

Ayush Chutani, a doctoral student working with Dyreson, is trying to develop single-axis solar panel tracking systems that can shed snow better. 

Ayush ChutaniHis first challenge was measuring the amount of snow on bi-facial solar panels that reflect snow from the ground as well as solar radiation from the sky.

“If you can see snow on the panels, the front is generating no electricity,” Chutani says. “On the ground, snow is reflective, so on the ground, snow is good. On the panels facing the sky, snow is bad.”

He used laser-based sensors that rotate with the panels, a novel approach, to calculate the amount of snow collected on the panels and how much snow they shed. “If we increase the angle, more snow might shed off the panels,” he explains. “We want to determine when the array should tilt and how much to shed the most snow.”

Davis, another of Dyreson’s doctoral students, is studying the effect of snow shedding on power grid operation. 

Shelbie Davis“Snow cover decreases the amount of light received by power plants. We need to consider the climate of the region, the ambient temperature and solar panel types to design a snow-shedding model at the power plant level,” she explains. “Then we need to develop a grid simulation using that snow-shedding model.” 
Dyreson says it’s vital to include the impact of snow in the development of utility-scale solar. Utility-scale solar — large solar power systems that generate electricity that is sold to utility companies, not individual consumers — is becoming the most common kind of solar energy power generation system in the nation, she explains. 

Dyreson credits former Tech Professor Joshua Pearce’s research with forming a foundation for her team’s work.

Pearce found that reflectors greatly increase the output of solar systems. To prevent loss of energy from light that hits the ground between panels, Pearce suggested filling the space with a reflector to bounce sunlight back onto the panels. His team designed a BDRF (bi-directional reflectance function) model that could predict how much sunlight would bounce off a reflector and where it would shine on the array. Properly placed, the reflectors greatly increased solar system output.

Dyreson hopes her research will help make large-scale solar energy systems 
a viable way to generate electric power in snowy climates like the U.P. 

“We’re excited to continue to test new technologies and how they perform in cold and snowy conditions,” Dyreson says.

Jennifer Donovan is a reporter with more than 40 years of experience on daily newspapers, magazines and university writing and editing. She is retired as director of news and media relations at Michigan Technological University and lives in Houghton.
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