We have already seen artificial windows from Samsung's SunnyFive startup, which are able to perfectly imitate the classic ones, e.g. in places where their installation is not possible, also in terms of sunlight. They produce the full spectrum of natural light, with the angle of incidence changing throughout the day, and according to their creators, we can also count on skin synthesis of vitamin D when indoors (without the risk of burns or skin aging), which is important in geographic regions where there is little natural light and it is virtually impossible to expose yourself to sufficiently long exposure.
Today, we can admire a more classic-looking, but at the same time equally technologically advanced solution, combining color-changing glass and solar panels. Scientists of the US Department of Energy's National Renewable Energy Laboratory (NREL) managed to use both technologies and create the so-called thermochromic photovoltaics. As a result, they obtained windows that not only change color when heated, i.e. allow to cut off excessive solar radiation on summer days and save on heating, but also are able to obtain energy from this radiation.
The windows are made of a thin layer of perovskite, which has been seen for some time as the future of solar panels, sandwiched streaming sites links directory two glass panels, with free spaces filled with solvent vapor. When humidity is low, the perovskite remains transparent, allowing light to pass through normally. However, at certain temperatures, the steam causes changes in the arrangement of the perovskite crystals, which causes a color change, thus blocking some light and cooling the room by several degrees. When the window becomes darkened, the process of generating energy also begins.
When the glass reaches a temperature in the range of 35-46 ° C, windows can change color from transparent to yellow, orange, red and brown, all in just 7 seconds. This is a huge improvement over the prototype, which could only change color after reaching 65.5-79.4 ° C, and the whole process took him 3 minutes. If it goes on like this, it will soon be possible to achieve the goal of reducing the need for air conditioning, which consumes huge amounts of energy on hot days and in warmer climates, and even providing it with a small injection of green energy generated through windows.