Summer sunshine fuels solar energy research at Tulane

While many students and faculty leave for the summer, the vital work of Tulane University continues. On the rooftop of Flower Hall, researchers in the School of Science and Engineering are taking advantage of long, sunny days to test a solar energy system designed to capture something most conventional solar panels waste: heat.

Traditional photovoltaic panels are only designed to convert certain wavelengths of sunlight into electricity, and the energy from the remaining wavelengths is lost as heat. In contrast, the Sunflower Receiver on the roof of Flower Hall is a hybrid concentrated photovoltaic system that generates both electricity and thermal energy from the same stream of sunlight. Researchers are using the platform to explore how solar technologies can produce more usable energy while reducing losses that typically occur in traditional systems.

Using a curved mirror, the system concentrates sunlight to nearly 500 times its normal intensity and directs it onto a compact receiver. The energy is then divided into two outputs: electricity generated by solar cells and heat captured through a water-based system. This combination of solar energy capture with a hot water and steam output produced system efficiency as high as 85%, compared to 20% from traditional solar panels.

Conor Farnan, a recent Tulane engineering physics graduate who worked on the project, said the goal is to use the heat, not lose it.

“In simplest terms, you get hot water and you get electricity,” Farnan said.

Researchers are integrating the system into a working building environment to better understand how much energy it can realistically produce and where energy losses occur.

“We’re actually integrating this with the building,” said Matt Graf, another recent Tulane engineering physics graduate. “So, it’s kind of proving that this can be a viable product in the market.”

The project examines not only energy production but also long-term economic feasibility. Researchers are evaluating operating costs and system performance while identifying potential customers to determine where the technology could be most effective.

Unlike traditional solar installations that focus solely on electricity generation, the Sunflower Receiver system is designed for customers with significant heating needs. Potential applications include food processing, bottling, paper production and other industries that require large quantities of thermal energy traditionally supplied by natural gas-fired boilers.

As the project continues to generate data, researchers are also exploring opportunities to bring the technology beyond campus. In June, recent physics doctoral graduate Sid Padmanabha presented the technology at the IEEE Photovoltaic Specialists Conference in New Orleans. He is now leading efforts to commercialize the system in partnership with the national Cleantech Open accelerator and Tulane’s Innovation Institute.

“We’re excited about the extensive pilot data we’re getting from our testbed, as it will help validate our potential for very high conversion efficiency at a competitive cost,” said Matthew Escarra, professor of physics and engineering in the School of Science and Engineering and lead investigator on the project.

The research team is also studying geographic regions where the technology could be most competitive, particularly areas with abundant sunlight and high conventional energy costs. Findings from the project could help guide future applications of solar process heat and electricity cogeneration technology in commercial and industrial settings.