A coalition of American and Italian researchers have made a breakthrough in developing technology that can turn any window into a daytime power source.

By covering windows with sunlight harvesting quantum dots, called luminescent solar concentrators (LSCs), the team says it is able “to disrupt the way we think about energy.”

Last year the researchers from the Center for Advanced Solar Photophysics at the Los Alamos National Laboratory in the US and the department of Materials Science at the University of Milan-Bicocca in Italy unveiled a small-scale version of the technology.

Not the Los Alomos researchers have scaled up from palm-sized demonstration models to windows large enough to put in and power a building.

Explaining the technology last year, lead researcher Victor Klimov said: “A fraction of light transmitted through the window is absorbed by nanosized particles, or semiconductor quantum dots, dispersed in a glass window, re-emitted at the infrared wavelength invisible to the human eye, and wave-guided to a solar cell at the edge of the window.

“Using this design, a nearly transparent window becomes an electrical generator, one that can power your room’s air conditioner on a hot day or a heater on a cold one.”

The new demonstration has added thin layers of the dots on top of commercial large-area glass slabs using the ‘doctor-blade’ technique used in printing, in which a blade wipes excess liquid material from a surface and leave a thin, highly uniform film behind.

Klimov believes LSCs are much cheaper to install than photovoltaic cells over a comparable surface area, and said if the power generation is found to be sufficiently high, the technology can soon be used “to turn presently passive building facades into power generation units.”

Speaking last year, Sergio Brovelli, the lead researcher on the Italian team, said the technology will allow windows as well as rooftops to be used to generate power in densely populated urban areas. He estimated that if you replaced the passive glazing of a skyscraper such as David Childs’ One World Trade Center in New York – which has 12,000 windows – with the quantum dot technology, it would be possible to generate the equivalent of the energy needs of over 350 apartments.

Unlike previous iterations of the quantum dot solution, the new version absorbs more solar light and does not contain any toxic metals.

A number of breakthroughs in window innovation have taken place this year – from self-shading to transparent wooden windows – paving the way for architects and designers to think about how they can use windows to reduce energy requirements while generating power in their own right.

Will the windows of the future be made from transparent wood?