Improving Solar Efficiency with Stanford coating

Stanford engineers invent transparent coating that cools solar cells to boost efficiency.

A transparent material that can improve the efficacy of solar cells, this coating has been invented by three Stanford engineers and has the tendency to radiate thermal energy into space which is released by solar cells, making cells cool.

This invention shunts away the heat generated by a solar cell under sunlight and cools it in a way that allows it to convert more photons into electricity.

The group’s discovery, tested on a Stanford rooftop, addresses a problem that has long bedeviled the solar industry that, the hotter solar cells get, the less efficient they become at converting the photons in light into useful electricity.

The Stanford solution is based on a thin, patterned silica material laid on top of a traditional solar cell. The newly developed transparent coating is made up of thin, patterned silica material. It works by capturing intense heat or thermal radiations from infrared rays and emitting them into atmosphere.

When laid over a solar cell, the transparent material can radiate heat away from solar cells, allowing them to produce electricity more efficiently.

Solar arrays must face the sun to function, even though that heat is detrimental to efficiency.The thermal overlay allows sunlight to pass through, preserving or even enhancing sunlight absorption, but it also cools the cell by radiating the heat out and improving the cell efficiency.

One of the biggest challenges facing solar technology is that solar panels lose efficiency when they heat up, a problem since these devices also need to be faced toward the sun to best generate electricity. The Stanford researchers had a different idea. What if you could cool down the sunlight itself?

The key principle in the system works in a way analogous to how your own body radiates heat. As you walk around on a daily basis, heat from the top of your head radiates into space as infrared light.

The researchers devised a transparent coating comprised of patterned silica that lets visible sunlight through, but which captures and emits the thermal radiation from the infrared rays.

The team tested their sunlight-cooling system on a custom-made solar absorber, a device that mimics a solar cell without actually producing electricity positioned on a Stanford rooftop.

They found that the absorber was cooled by as much as 23 degrees Fahrenheit thanks to the coating. That essentially translates into a 1 percent increase in solar efficiency. That might not sound like a lot, but it is actually quite significant in terms of overall energy production.

Engineers stated that their invention would prove beneficial in nanoprint lithography technique used to develop nanometer-scale patterns.

They added that the new thermal coating could prove best when used in dry, clear environments.

The technology could also have applications beyond improving solar cell efficiency. For instance, it could help keep darker-colored cars cool as they sit in the sunlight. Windows coated in the silica material could also let in light without letting in the heat.

Researchers hope that further developments in the technology will also improve its effectiveness, which will make solar energy more feasible than ever before

For more information please visit: www.stanford.edu

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