Prof. Gabriela S Schlau-Cohen

Thomas D and Virginia W Cabot Associate Professor of Chemistry

Primary DLC

Department of Chemistry

MIT Room: 6-225

Assistant

Paula Robinson
paularob@mit.edu

Research Summary

Unlike human-made electric grids, the natural world’s energy-harvesting systems never experience blackouts. Gabriela Schlau-Cohen, assistant professor of chemistry at MIT, is trying to learn from this natural talent for energy-making so she can change our energy systems for the better.

For Schlau-Cohen, this means starting with plants. Plants are the ultimate energy-users: The average global rate of photosynthesis is 130 terawatts — a level of energy-capture more than six times worldwide energy consumption. “Leaves absorb light throughout the visible spectrum, and they basically funnel all of that energy to a dedicated protein where electricity is generated,” Schlau-Cohen says. Plants’ ability to convert sunlight into electricity is two- to three-fold higher than that of a typical solar photovoltaic (PV) system.

With this in mind, Schlau-Cohen and her colleagues set out to unlock plants’ energy secrets. They began by studying the basic physics of plants, with the eventual goal of mimicking these natural characteristics in a human-made system. Through the MIT Center for Excitonics, Schlau-Cohen and her team are able to experiment with cutting-edge technology for bio-inspired artificial light-harvesting systems.

One of the most important takeaways from her study of plants isn’t the discovery of a single plant structure or chemical that makes natural energy processing so efficient, Schlau-Cohen says. It’s the economic choices represented by the operation of the system as a whole.

To deal with this challenge, the energy-harvesting pathways in plants are designed to strike a balance between being hardy enough to operate in full sunlight and finely tuned enough to make the most of low sunlight conditions. Increasing the amount of time the system can be active has economic advantages as well. Natural systems optimize by making sure their most energy-expensive machinery is always in use so that they can get the most out of it. “Through complicated feedback loops implemented in its molecular machinery, the system responds to changes in solar intensity,” says Schlau-Cohen. This responsiveness addresses the intermittency problem, while also ensuring that the plant structures that take the most energy to develop are used to their full potential.

Based on their new understanding of plants’ energy-harvesting pathways, Schlau-Cohen and her team are finding ways to control for different variables — creating biomass, for example, rather than protecting the system against too much sunlight. “If we rewire those pathways for optimizing biomass, we can get a 15 percent increase in biomass, or even 30 percent under some conditions,” she says.

As Schlau-Cohen tackles these issues at the forefront of energy knowledge, she finds a source of inspiration in her research community. When she made the decision to come to MIT, the students were a particular draw. “I think MIT students are the best of the best, not just in terms of their smarts, but in terms of their excitement about science,” she says. “That was something I could not turn down, because I felt like they would make me the best scientist I could be.” The students have not disappointed, providing both inspiration and fun -- Schlau-Cohen’s very own source of renewable energy.

Recent Work