NREL’s Solar-Powered Smart Window Achieves 11% Efficiency


Imagine a smart window that could capture sunlight and not only lower building temperatures, but also convert it into electricity? Now, wouldn’t that be cool?

The National Renewable Energy Laboratory (NREL) has revealed a new solar-powered smart window prototype with an 11.3% efficiency rating. It could also provide 80% of the United States’ electricity needs.

The smart window technology that is developed can keep the heat out of the buildings and work as a solar panel and convert sunlight into energy.

Smart Prototype

The smart window can lower building temperatures whilst shifting from clear to opaque and also begin electricity production in the process. The windows are featured with a Low-E (low heat emission) glass used by 80% of residential units in the USA. Advanced materials such as perovskites, a calcium titanium oxide mineral, and single-walled carbon nanotubes, microscopic structures with remarkable strength are the foundation of this new technology. And, the colour change (reversible) is attributed to methylamine (molecules).

How does the chemical reaction work?

The insulated windows have multiple layers of glass like the absorber layer composed of metal halide perovskite-methylamine complex. The photothermal heating initiates the absorber layer from a transparent state to an absorbing, photovoltaic coloured state due to methylamine dissociation during illumination. After cooling, the methylamine complex gets re-formed, thus returning the absorber layer to the transparent state wherein the device works as a window to visible light.

Proof-of-concept Paper

The paper titled ‘Mechanism of switchable device degradation’ highlights the chemical issues that lead to degradation. Lance Wheeler, a scientist at NREL, stated in this context that though there are many thermochromic technologies, nothing actually converts that energy into electricity.

The Road Ahead

The smart window has its challenges to balance the sunlight keeping it sufficient for mental well-being and using sunlight to produce electricity. Meanwhile, the technology could also be integrated into buildings, vehicles, and more.

Leave a Reply