Solar project shows way forward for MIT as lab for sustainability innovation

Wednesday, April 22, 2015

Anna Nowogrodzki

MIT professor Tonio Buonassisi has seen a lot of students tackle project-based learning, and it’s almost always intimidating. “It is kind of that moment of courage for them, when they’re at the edge of the pool looking into the water, trying to decide whether they jump in or not,” he says. But he had a unique group of students this fall semester in his Fundamentals of Photovoltaics class. “This group was in the water before I even said go.”

The team of five graduate and undergraduate students—Delphine Kaiser, Isaac LaJoie, Jeremy Poindexter, Conrad Sanborn, and Emily TenCate—designed a class project aimed at starting a conversation on the solar potential of campus rooftops. According to the model they developed, there is enough roof space at MIT suitable for solar installations that the Institute could generate 4.3 megawatts of electric power. That’s about 14% of peak campus demand for electricity. The students’ calculations showed that were MIT to install the panels, they could pay for themselves in less than seven years.

The students came up with the idea, says Buonassisi. “It was really them leading the charge.” The team met with President Reif in December, and at his recommendation, they presented their findings to Tony Sharon, Deputy Executive Vice President of MIT. Poindexter discussed the project to a crowd of 125 students, faculty and staff at SustainabilityConnect, an event coordinated by the Office of Sustainability this March (his talk is online here, starting at 22:10). The Department of Facilities is now able to use the team’s findings as a resource as the Institute explores what the most sustainable uses of its roof space may be. Roof space is the "other ground" in an urban environment, and the range of possible uses includes energy generation strategies such as solar, as well as green roofs and cool roofs, that help mitigate stormwater, the urban heat island effect, and other effects brought on by climate change. MIT has committed to validating the students’ model by applying it to some current capital renewal projects, says Steve Lanou at the MIT Office of Sustainability.

It was a pleasure to teach students with such “fire in their bellies,” says Buonassisi. “When I see a group like that, you want to…do whatever is within your power to help them out.”

One key part of the project’s success, says Buonassisi, is the fact that others at MIT wanted to help them out, too. “The Office of Sustainability and the Department of Facilities are so eager to work with the students,” he said.

To Buonassisi, projects are an invaluable part of students’ education, because they have to break out of the traditional classroom model of “you follow instructions and you get an A,” and instead engage with a more complex process of “being project managers, identifying your own interests, dealing with uncertainty, facing it, and then resolving it. And then feeling that sense of accomplishment.”

The project was very simple, says team member Jeremy Poindexter, a second-year PhD student in materials science in Buonassisi’s lab. They focused on two questions: how many solar panels would fit on existing MIT roofs, and how much they would cost.

The team found a useful tool that allowed them to assess how intense the sunlight was on every roof on campus without setting foot on any of them. The tool,, was developed by Christoph Reinhart, Associate Professor in the MIT Department of Architecture, and allowed the team to determine which roof areas on campus get enough sunlight to allow solar cells to pay for themselves in seven years or less. Then they weeded out roof areas that were obstructed by exhaust fans, vents, and the like.

The students found the best solar potential on top of the Zesiger Athletics Center. “It’s beautiful, it’s huge, it’s open, it’s completely flat: it’s asking for solar panels to be put on top of it,” says Poindexter.

Currently, the Institute generates 0.07 megawatts of power—0.2% of peak campus demand for power—from its five solar installations (on the Stratton Student Center, Building N52, the Hayden Library, the Alumni Pool, and the Sloan School).

As a student in the photovoltaics lab, Poindexter noted that he would welcome the opportunity to have access to a rooftop laboratory on campus to conduct research. Such a laboratory, he thinks, would likely spur innovation and collaboration that can't be predicted. “People are very, very creative,” he says.

“The solutions of climate change are really a question about scalability. We know we have a global problem. The solutions are going to have to be tested and implemented at a very local scale,” Lanou says. MIT is not unlike a small city, and solutions developed and tested on campus could be scaled up for cities, states, and countries.

The students in Buonassisi’s class dove right into this kind of solutions-seeking. “What’s unique about universities is that they have incredible intellectual resources” that they can draw on to tackle these problems, says Lanou. One way to facilitate this would be a program that connects students with opportunities to use the campus as a laboratory for sustainabilty innovation. It’s “a way of leading,” says Poindexter, “that I think has a lot of opportunity.”