Storing the Sun’s Energy

Solar and wind are at the forefront of the clean energy movement in the global effort to mitigate the effects of climate change. These renewable energy sources effectively lower carbon emissions, but the imbalance between energy production and energy demands remains an obstacle.

Solar panels, for example, transform sunlight directly into electricity, but the electricity must either be used immediately after it is generated or stored using batteries or other means. And because storage technologies are not yet as mature as solar panels, fossil fuels are still used for back-up energy when the sun is not available.

To address this challenge and make clean, renewable energy a continuous power source, a team of researchers received $1,100,000 from the U.S. Department of Energy. Instead of using solar power to produce electricity, they plan to store it directly in a chemical fuel. And they took inspiration from nature itself to achieve this goal.

“During photosynthesis, plants absorb carbon dioxide and water from the air and soil, and light sets off a reaction that produces oxygen and energy stored in sugars, like glucose,” said James McKone, assistant professor of chemical and petroleum engineering. “In this project, we want to mimic this natural process by using non-biological materials to create a sort of ‘artificial photosynthesis.’”

The collaborative group, led by Giner Labs in Newton, Mass., will improve existing solar-powered water electrolysis technology to extract hydrogen from water and use it as a fuel source.

“Hydrogen is attractive because it is a fuel with no carbon,” McKone explained. “It is storable, transportable, and burns cleanly, producing power without polluting the environment.”

The goal of the project is to create a technology that works roughly 10 times better than the most efficient green plants.

“When you design a product, it needs to be efficient, cost-effective, and robust,” McKone added. “No one has successfully combined all three of these characteristics in one fuel-generating device.”

Current high performance water electrolysis technology operates under acidic conditions, a costly characteristic that can degrade device materials. In this work, the research team will develop a less corrosive system that works under basic (alkaline) conditions, which could significantly lower costs and improve long-term stability.

“The simple switch from an acidic polymer electrolyte to an alkaline one allows us to remove all of the expensive metals such as iridium, platinum, and titanium from the electrolyzer system, and this paradigm shift is critical for making the generated hydrogen cost competitive,” said Yushan Yan, CEO of Versogen, who will also collaborate on the project. “Versogen has been aiming to develop the world’s best alkaline polymer electrolytes and is really excited to work together closely with University of Pittsburgh and Giner for this important project.”

This award is part of the DOE’s Small Business Innovation Research (SBIR) program, which was established to encourage diverse communities to participate in technological innovation, as well as create a bridge between DOE-supported science breakthroughs and viable products and services for the commercial market.