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Drone data helps Minnesota city save energy

Originally posted on

Maintaining healthy and comfortable buildings can be costly in Minnesota, especially during polar vortex events. Warren, a small town in northern Minnesota, offers an innovative public service: images revealing heat loss from buildings, captured by drones.

For this episode of the Local Energy Rules podcast, host John Farrell chats with city administrator Shannon Mortenson of Warren, Minnesota. Mortenson and the city have partnered with a community college to pilot a new project; the college, using drones and thermal cameras, captured images that show energy leaks in homes and businesses. Farrell and Mortenson discuss the one-of-a-kind thermal imaging project, lessons learned from the pilot, and how cities can help residents conserve energy.

Listen to the full episode and explore more resources below, including a transcript and conversation summary.

Episode transcript

Warren sets his sights on cutting-edge technology

Warren owns his utilities, including electricity and gas, so Mortenson’s role as a city administrator includes overseeing the city’s energy supply. Warren does not generate his own electricity. Instead, the city is part of a conglomerate of small towns that collectively buy their electricity from Minnkota Electric Cooperative (and their gas from Constellation Energy).

Warren is also part of the Climate Smart Municipalities Partnership, where cities in Minnesota and Germany collaborate on sustainability and climate issues. Warren is in partnership with Arnsberg, Germany. Warren and Arnsberg devised a plan to perform thermal analyzes of their communities to visualize building inefficiencies and heat loss.

“Everyone is asking, ‘how can I save money in my own home? And the cities are trying to figure out, “How can we help our residents? How can they save energy? Our energy costs keep rising, how can we be good stewards of our energy use? ‘ “

Community, Collegial partnership

Northland Community College, near Thief River Falls, offers a drone program for students and was a natural partner for Warren. Starting in 2017, Northland students would take thermal images of every building in Warren using drones.

After the drones take the photos, the students assemble them and correlate them with a Warren map. They’re currently stitching the images together, Mortenson says. Cards will soon be available to residents of Warren.

“Our plan is to take this data and allow residents to come in, sit down with the staff and see where their biggest loss of energy is in their home …”

Data collection by trial and error

Drones fly over the city at 200 feet and, using a thermal camera, document the amount of energy leaking from buildings. Imaging should be done with the ovens turned on, but the air temperature should be at least 32 degrees to maintain the drone’s battery. The air should also be still. Overall, these conditions leave a small window of opportunity for imaging in late fall.

During their first attempts at imaging, the students also realized that photos should be taken in the middle of the night. When the photos were taken shortly after dusk, the residual heat on the rooftops read like heat loss on the map. Taken early in the morning, the sun would soon heat the roofs. Residents were told drones were flying, so there would be no confusion about the flying objects.

The “Val Johnson Incident”, a notorious UFO sighting, took place in Warren in 1979.

Mortenson believes Warren’s partnership with the college has been essential. She and the supervising professor hope that the students will start a business and offer the thermal imaging service to other municipalities. The COVID-19 pandemic has slowed progress, Mortenson says, since enrollments at Northland Community College are down and students have been absent from the classroom.

Invoice financing for energy efficiency improvements

Thermal analyzes help homeowners identify how their buildings are losing heat. With this information in mind, they can further insulate their home through airtightness, weatherstripping, or attic insulation. They can choose to completely replace their doors or windows.

Energy efficiency upgrades pay off over time as they lower energy bills, but many can’t afford the upfront costs of an upgrade. Bill financing, sometimes referred to as Pay As You Save, ensures that everyone can make their home efficient and comfortable.

In 2019, Warren participated in an inclusive funding feasibility study. Under the program, the building owner takes out a loan from the city to improve energy efficiency. They repay the loan from savings on their utility bills – and the loan remains with the property, not the resident. Once the loan is repaid, the resident pockets the savings made on his energy bill.

“Their bill shouldn’t change. But then after the specified amount of time, which would probably be around two to three years, after the loan was paid off, then of course they would still see that savings on their bill.

For privacy reasons, the City of Warren cannot use thermal images to target people who may benefit from efficiency improvements. Owners and business owners should approach the city and request their data.

In the footsteps of Warren

Mortenson says city officials in Texas, Illinois, and Iowa all approached her out of interest in the Warren pilot project. Her advice is to find a partner like Northland Community College. The college already owned the drones (each priced at $ 40,000) and used the project as a learning opportunity for the students.

Warren was also an ideal community to pilot thermal imaging as it owns its utilities. The municipal non-profit utility had no incentive to fight the project, as energy efficiency only helps city residents. For cities that don’t own their utilities, Mortenson believes thermal imaging remains a worthwhile investment. The data informs residents about their energy consumption, which they can use to save energy, money and better pay other bills.

“I think it’s just good to know where your energy loss is in the community and how can we be more effective? How can we be good stewards and try to mitigate climate change and increase the sustainability of our community? “

Episode Notes

Check out these resources to learn more about the story:

For real-life examples of how cities can take action to better control their clean energy future, explore the ILSR Community Toolkit.

Explore local and national policies and programs that help advance clean energy goals across the country, using ILSR’s interactive community power map.

This is the 141st episode of Local Energy Rules, an ILSR podcast with Energy Democracy Director John Farrell, which shares landmark stories of successful local renewable energy and exposes the political and practical obstacles to its expansion.

Local Energy Rules is produced by John Farrell and Maria McCoy of the ILSR. Audio engineering by Drew Birschbach.

This article originally appeared on For timely updates, follow John Farrell on Twitter, our energy work on Facebook, or sign up to receive the weekly Energy Democracy update.

Photo credit featured: Lars_Nissen from Pixabay

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