Building greener from the ground up

fall 2022 Inventing tomorrow

During a stint as Chicago’s chief sustainability officer, Sandra Henry wrote the ordinance the city adopted to become the largest metropolis in the United States to commit to 100 percent clean energy.

That’s just one career highlight of this Minnesota- trained engineer—and Master Gardener—whose life has been intertwined with the emergence of the sustainability movement.

Henry was an accounting major on the University of Minnesota Twin Cities campus when a professor took her aside, complimented her talents in math, and suggested she take calculus. She followed his advice. With more encouragement from the same mentor, Henry soon discovered that she also loved physics.

“The concepts and ideas were really interesting to me,” she recalled. “Being able to explain your physical world through math and science was really fun. I decided to change my major to mechanical engineering.”

By her senior year in 1991, Henry had gained enough engineering experience to secure a job at Northern States Power (now Xcel Energy) where she developed Saver’s Switch. The program has since helped millions of residential users conserve energy by remotely switching consumer loads on and off. She wrote software, designed the control protocols, and made decisions about equipment, installation, and operations.

“I realized that the most cost-effective unit of energy is the one we don’t produce,” she said. “That was the beginning of realizing that I could spend a career doing this kind of work and really have fun at it.” As it turned out, a new branch of engineering was taking root. “We didn’t call it ‘sustainability’ at that time,” she said with a chuckle. “It was ‘direct load control’—not a very sexy name.”









Henry spent nearly two decades as a manager and consultant for utilities in Minnesota and Illinois, including the Chicago-area utility ComEd. Most programs it now offers, she had a hand in either creating or running.

In 2015, Henry shifted into the nonprofit sphere in order to pursue deeper systemic changes. One obvious target is buildings, which are responsible for nearly half of global carbon dioxide emissions.

“Once you build a building, it’s there for 40 or 50 years,” she explained. “If you want to make an impact on its carbon footprint, it’s better to have that conversation before you build it. That’s the conversation I wanted to be in.”

From 2018 to 2019, Henry served as the chief sustainability officer for the city of Chicago. During her tenure, she drafted a resolution to transition all city- owned buildings to 100 percent renewable energy by 2035 and to convert all Chicago Transit Authority buses to electric energy by 2040. The Chicago City Council unanimously approved the measure and subsequently adopted a series of additional conservation measures.

Since then, several Chicago-area organizations devoted to making buildings greener have benefited from her expertise. In 2022, she became the president of Slipstream. The nonprofit, with employees across the United States, develops clean energy solutions that can be deployed at large scale while ensuring equitable access.

“We cannot have a clean energy transition and resilient future unless everybody is on board, from the folks who can afford it to the ones who cannot,” Henry said. “We have to be inclusive in our discussions.”

When not working to reduce carbon footprints, Henry enjoys leaving her own footprints in the soil. During her years in Minneapolis, she discovered a love of gardening and earned a Master Gardener certificate from the University of Minnesota. Her hobby has provided a window on climate change: she has witnessed the growing seasons getting longer and rising temperatures affecting what plants can thrive in northern climates.

“We are almost at the point now when we cannot stop this climate change train,” Henry reflected. “But we can be more resilient and we can be more mindful. A lot of it comes back to reconnecting people to the earth—and gardening is a great way to do that.”