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Smart and connected technologies are beginning to infiltrate all areas of our life. From smart light bulbs and smart thermostats to connected doorbells and connected wearable health trackers, these technologies are helping streamline our lives, bringing convenience to day-to-day tasks and helping us to be healthier.
In addition to this, one main function of smart technology is focused on optimizing energy consumption, driving down energy bills and helping to support the adoption of renewable energy sources.
What are Smart Windows?
Smart windows have been developed as a technology that can assist in driving down energy bills by using solar energy to power transitions from transparent to completely blocking out light. As well as making curtains redundant, this kind of control over letting in light can also govern how much warmth is let into a building or home at any one time, having the impact of reducing heating bills. It can also reduce the need for use of electrical lights, as sunlight can be relied on like a light source when possible.
Studies have shown that around 40% of a building’s average energy costs can be saved using smart windows. They can be controlled through connected devices such as phones or tablets, or through a wall-mounted dashboard.
However, until recently, the energy requirements of this kind of glass was an expensive investment that often outweighed its energy saved benefits. In 2017 this all changed as innovations in the technology were made that resulted in the windows being able to be completely self-powered through solar energy. Scientists developed a film that allowed these windows to become self-powered.
How the Technology Works
Smart windows are powered by UV light, but unlike solar panels that are black because they absorb all visible light and some infrared heat, smart windows only need to absorb UV light and so the cells are transparent as to not take away from the window’s aesthetic and incorporate semiconductors to function.
Organic semiconductors (hexabenzocoronene (cHBC) derivatives) have been incorporated into solar cells to absorb near-UV light. Scientists have constructed these solar cells by distributing semiconductor molecules throughout thin films that are used to coat the glass. The same processes that are used by organic light-emitting diode manufacturers to create these film-covered cells.
The cHBC semiconductors within the thin film become excited in the presence of sunlight, which has the impact of generating electricity. This electricity is then used to power the smart window, meaning that the energy needed for changes in light resistance of the window can be fully powered by the sunlight shining onto the glass. Electrochromic polymers are powered by the solar cell which can control the level of tint over the glass at any moment.
What scientists are working on next is applying this technology to create a laminate film that can be added to regular windows to turn them into smart windows. This will eliminate expensive setup costs and make smart technology accessible to all buildings and homes. The idea is that the wireless smart window laminates would incorporate the same technology as the glass, but in a laminate that would have a sticky backing, that once peeled off would be adhesive to a window surface.
The laminate cover would then, in theory, be controlled by an app via smartphone or tablet. We can expect this advancement in smart window technology to support its widespread adoption, helping homes and businesses reduce their energy bills and be more environmentally conscious.