A snowy winter has put a significant damper on the output of the solar panels Karl Wagner and Danielle Rhodes installed on the roof of their home in Duluth's Observation Hill neighborhood. Even a partial obstruction of a solar panel's cells can greatly diminish its ability to generate power.
But getting up on a roof to physically clear snow and ice off the panels can be a precarious and potentially dangerous task. There had to be a better way, they thought.
That idea was gnawing away at Wagner when he learned of a competition — the U.S. Department of Energy's American-Made Solar Prize — from some Arizona State University graduate students he met at a solar-themed event hosted by Bent Paddle in Duluth.
After that chance encounter, Wagner emailed contest organizers to see if anyone could enter the competition. He heard back in early November that yes, the contest was open to all. But, by then, the deadline for entries was only about a month away, and Wagner had to scramble to meet it.
Wagner and Rhodes struck on the idea of building a frameless panel that would more easily shed snow. They also incorporated a super-efficient heating element into the design.
At a home-building show, the couple ran across a promising new material made by Electro Plastics Inc. that just might fit the bill: a nanoparticle heating film used in roofing, flooring and concrete surface applications. What's more, the company has demonstrated support for Rhodes' and Wagner's efforts to open a new solar market for its product.
The carbon and polymer membrane heats to a maximum of just 86 degrees and has the unique ability to target snow and ice.
"It's self-regulating. So, if part of the surface has snow on it and part of it doesn't, it focuses the energy on the part with snow," Rhodes said. "That means you're not paying to heat the whole thing as much."
Wagner acknowledged that melting off snow consumes a bit of energy, but if it returns a panel to full productivity, the cost of that manually triggered jolt is money well spent.
"What we're hoping is that it will use less than half of a day's worth of output from the solar panel. So, at the end of the day, it's either at zero or gaining a little bit of energy. Then, for the rest of the week, it will continue to produce energy," Wagner said.
"If you never really lose energy, you're always gaining," he said.
Wagner noted that conventional solar panels in northern Minnesota typically take an annual productivity hit of 10%-16% because of winter weather, but he maintains that a properly designed panel could drastically lower that loss.
The couple has also garnered support from Heliene Inc., a Canadian company with manufacturing operations in Mountain Iron.
Rhodes and Wagner put together a proposal and entered it in the competition. In February, they learned they had been named semifinalists.
Fewer than one in six contestants made the cut, with 20 semifinalists selected out of more than 120 applicants.
As they advance in the competition, Rhodes and Wagner have received $50,000 and the chance to compete for another $100,000 in prize money, as well as a $75,000 voucher for research at the Department of Energy's National Renewable Energy Lab. Half the semifinalists — 10 in all — will be chosen to receive this follow-on support.
The couple faces another short timeline to advance their proposal, which is due in May
With Heliene's help, they have graduated from a few small 1-square-foot prototype panels to several full 3½- by 5½-foot panels. The panel manufacturer provided Rhodes and Wagner with the panels in a partially assembled state so that they can incorporate their ideas into the panels and test them in the field — in this case, their backyard.
They also have brought another partner, Tyler Lande, a Cisco Systems and cybersecurity specialist, on board to provide electronic support and collect data on the performance of the larger prototype panels.
Rhodes said Lande, a 22-year-old who works at Altec Industries, will handle testing. Wagner heads up design and she oversees the business and marketing end of the enterprise.
Wagner, 29, earned a bachelor's degree in mathematics with a minor in energy engineering at the University of Minnesota Duluth. He worked first in the aeronautics industry and then moved into software.
Rhodes, a 30-year-old Realtor, also has a background in design and business startups.
While both Rhodes and Wagner hope to see their ideas one day in mass production, they're not necessarily looking to get into the manufacturing business themselves.
"The main goal is to see if this is a viable idea, and if it makes sense we'd be really glad to have it manufactured. Our interest is mostly in the R&D (research and development) part though, because it's fun," Rhodes said.
Wagner said the snow-shedding design they're developing could be of great help sustaining solar power in remote off-the-grid locales, such as weather stations, seismometers and even ocean buoys mounted with electronic monitoring equipment.
Wagner believes the greatest design challenge will likely be figuring out how to properly support a frameless solar panel from below, but he's confident it can be done, especially with the help of advanced adhesives.
Rhodes, who is secretly hoping for a snowy spring, described Duluth as an ideal place to put panels through their paces.
"It seems like we get unusually harsh conditions, which are great for testing," she said.
Even if their work does not result in a major breakthrough, Rhodes said it could be significant in an industry where even small increases in efficiency draw attention.
"In the world of solar right now, the technology is pretty advanced," she said. "So, people get really excited about a 1 or 2% gain in efficiency. If we can accomplish something even that minuscule, it's actually really a big deal. Those kinds of incremental increases are valuable."
Wagner has been fascinated by solar energy since his youth. He still recalls a toy kit car powered by solar cell that he received at age 12. Intrigued, he turned to eBay to purchase more solar cells to power additional creations and unwittingly stumbled into owning a number of early devices developed during the height of the space race. His acquisitions include an early solar cell hand-built for Bell Laboratories and another one designed for the International Space Station.
Many of these items are now viewable through a catalog of Wagner's collection available at solarmuseum.org.
Rhodes' and Wagner's shared scientific curiosity has drawn them in numerous directions. In addition to the solar contest, they also are currently finalists in a NASA competition to see how much lettuce can be grown in a 20-inch cube minus gravity. The pair's design can support 30 heads of loose-leaf lettuce at a time.
Sure, there's a $500 prize for the winner, but Wagner says that what he really wants is to take home a NASA mug.
This story originally misrepresented where Kurt Wagner met the Arizona State University graduate students. They met at Bent Paddle in Duluth. It was updated at 8:26 p.m. The News Tribune regrets the error.