There is nothing more exciting than learning about the development of a new technology that sounds like it is straight out of a science fiction novel. Think about it. Not three or four decades ago it was science fiction to think that virtually every person in the world would have an incredibly powerful computer right in their front pocket. Today we have cell phones that not only allow us to communicate with anyone around the globe, but also have microprocessors that move at lightning speed.
Remember encyclopedias? It was once science fiction to imagine that a person could get the answer to any question under the sun with just a few taps on a screen or a simple voice command. Now we can access the internet – an encyclopedia of all human knowledge – and have our questions answered within moments. And remember albums, 8-track tapes, and compact discs? Any music from anywhere in the world is now just a tap away, without the need for tape or disc players.
Well, in the window tinting tech world picture if you will a kind of window that can change from transparent to opaque based on the temperature, and can harness the energy of the sun and convert it into usable electricity. Imagine an office building that is entirely powered by the sun – through solar windows. Imagine a car that can run on solar power alone. Science fiction? Not for long.
Here at Tint Tech we specialize in auto and residential window tint films. But, we also keep our eye on the horizon. Our experts at Tint Tech like to know what new types of technological breakthroughs are happening when it comes to window tinting in general. And, hands down, we are excited about the new kind of smart windows that darken in the sun and generate electricity.
Perovskites – Ushering in a Solar Power Revolution?
In recent years, solar power has made some huge strides. Most of that is due to crystalline compounds called perovskites. Related to a mineral discovered in 1839 and named after Russian mineralogist Lev Perovski, perovskites have sparked a solar power revolution.
Solar cells made from perovskites are nearly as efficient as the silicon solar panels currently in use today. The best perovskite solar cells can convert over 22% of the sunlight’s energy into electricity, whereas silicon cells can covert around 25%. The key, however, is that cells made from perovskites are much cheaper than their silicon counterparts. That fact may push the solar energy world into high gear. Given the state of our environment, that might be just what the doctor ordered for Mother Nature.
“Smart Windows” based on Perovskites
Taking the solar harnessing power of perovskites one step further, perovskites can be the compound that leads us to “smart windows.”
In general, a “smart window” is a window that can change from transparent to darkly shaded based on the amount of sunlight and temperature. The warmer it gets, the darker the window becomes to keep any interior cool. The huge high-rise office buildings in city centers can truly benefit from such technology, with massive energy savings. In the past, there were other attempts at “smart window” technology that did not use perovskites, where the window would transition based on temperature, but it was costly and inconsistent.
In addition, “smart windows” using perovskites can also harness the power of sun to generate electricity. As noted, the solar cells using perovskites are almost as efficient as silicon panels. So, combining tinting technology with solar power technology, perovskites are truly the key to the “smart windows” of the future.
How Does the Smart Window Work?
About one year ago, researchers developed a lead-based perovskite solar window that transitioned from transparent to opaque when the temperature hit 60 degrees Celsius. When it is cool, the perovskite material forms a complex with another compound called methylamine. The window is clear when that complex is formed.
However, when it gets warmer, the methylamine vaporizes and separates from the perovskite, and the perovskite gets darker and absorbs sunlight. Then, at night when it gets cooler, the methylamine vapor re-bonds with the perovskite and the window becomes clear again. The chemical reactions that result in such practical applications are amazing.
It should be noted that when the perovskite is absorbing sunlight as it is tinted darker, it is not as efficient as the perovskite cells discussed earlier. The warmed perovskite tinted window can transform about 11.3% of the sunlight energy into electricity.
Is There Any Downside to the Current Smart Windows?
Without question, the technology is there but not quite ready for prime time. The solar efficiency of the solar windows drops after only a few transitions from light to dark. That is most likely because the methylamine does not re-bond with the perovskite very well, and worse each time.
So, researchers are looking for perovskite-based smart windows that do not use methylamine. One chemist reports that cesium-based perovskite solar windows, that do not use methylamine, allow for windows that can switch from transparent to dark with no loss of performance over time.
However, the cesium-based windows also have issues. First, they do not go from clear to dark unless the heat is more than 100 degrees Celsius, and their solar harnessing efficiency is only at 7%, which is far less than conventional solar cells. Finally, perovskite windows have a reddish hue to them when they are dark, and colored windows are not a favorite among builders.
It looks like the verdict on “smart windows” is that the future is almost here, but not quite. The latest science, however, provides a wonderful glimpse at what the future could look like – office buildings and homes that have windows that both provide shade when the sun is strong and can convert the sunlight to electricity to power the office building or home. Just imagine what life would be like without the need for electric wires coming into your home, or the need for oil to heat your home or office tinting.
If you want to learn more about what Tint Tech, Calgary’s window tinting experts,can do for you now with regard to saving energy by using state-of-the-art window tinting film call us at 403-968-8468. Also, contact us if you would like to learn more about the smart window tinting technology of tomorrow.