New technologies sometimes arise when two (or more) existing technologies are combined. This is such a story.
Thermochromic windows (sometimes called ‘smart windows) are ones that respond to heat by becoming tinted, thus filtering out sunlight on hot days, reducing energy consumption and enhancing the comfort of occupants.
There are also solar windows that can convert solar energy to electrical energy. These windows usually only convert a very small fraction of the visible light allowing the majority to pass through providing enough light for the building occupants to see. The result is a very low efficiency in the conversion of solar energy to electrical energy.
Scientist at the National Renewable Energy Laboratory (NREL) in the USA have combined these two technologies to develop thermochromic windows that convert the absorbed sunlight into electricity as they darken. The resulting product acts as an efficient solar cell when it is very sunny and a good window when it is not.
The original paper was published in Nature Communications.