Old is new again ─ hybrid device captures solar energy and stores it

The new system gives improved performance for solar energy harvesting over the old system. (Image Credit: University of Houston)

It’s been a long and anticipated process, but vintage solar energy storage research from the 1980s is finally starting to show some results. Researchers from the University of Houston in Texas have demonstrated a hybrid system that collects and stores solar energy in the form of heat for 24/7 use. The system doesn’t rely on molten salt or specialized oils, but instead, it involves using norbornadiene-quadricyclane. The team presented their findings in Joule. It also can be used for applications from power generation to distillation and desalination. The team has reported a harvesting efficiency of 73% at small-scale use and 90% at large-scale use.

Since 1983, norbornadiene-quadricyclane has been examined for solar energy storage, which was the same time the American Chemical Society published a paper in the journal Industrial & Engineering Chemistry Process Design and Development.

Solar energy in the form of heat is used in the center of a norbornadiene-quadricyclane energy storage system to flip one isomer to another. Sunlight then produces a reaction in norbornadiene, causing it to transform into quadricyclane. This is a switch from a low energy state to a high energy state, which is where energy storage comes into effect.

Renewable energy researchers have started to show interest due to the potential for high energy density in a norbornadiene-quadricyclane energy storage system. In November 2019, researchers from the University of Houston in Texas cooked up a new norbornadiene-quadricyclane energy storage system to solve some issues that prevented commercial development. 

The research team combined solar energy harvesting with energy storage in a single hybrid device. This gives it an advantage because it doesn’t sustain any losses when transferring energy from a collection device to a storage unit. This results in a high-density system that has the ability to capture solar energy for immediate use while converting excess energy into molecular energy storage.

“Here, we combine the physics of molecular energy and latent heat storage to introduce an integrated, simultaneous harvesting and storage hybrid paradigm for potential 24/7 energy delivery. The hybrid paradigm utilizes heat localization during the day to provide a harvesting efficiency of 73% at a small scale and ∼90% at a large scale.” The paper describes in the journal Joule.

The team also says, “Remarkably, at night, the stored energy by the hybrid system is recovered with an efficiency of 80% and at a higher temperature than that of the day, in contrast to all of the state-of-the-art systems.”

This new system has the ability to capture the entire light spectrum and not just a portion of it, in the same way, solar cells harvest energy.

The next step for the new system might be to apply it on different applications, with a focus on optimization performance and scaling up. It could be a while for the new system to make an appearance in the everyday world for power generation.

Have a story tip? Message me at: cabe(at)element14(dot)com

http://twitter.com/Cabe_Atwell