Scientists at Stanford University have just developed a new kind of cooling panel that may effectively reduce the cost of your air conditioning bill. The team, composed of Professor Shanhui Fan, and graduate students Aaswath Raman and Eden Rephaeli, wanted to achieve the goal of developing a structure that could cool buildings even while the sun is shining. They wanted to succeed "where others have come up short".
What the cooling panel does is that it effectively reflects sunlight, and at the same time sends heat back into space. The team says that the reflection aspect is very important because many other reflectors are poorly engineered, so they absorb too much sunlight, defeating the entire point of their existence. With the reflectors on the team's new cooling panel, the "vast majority of sunlight" is reflected.
The second part of the panel radiates heat, from the structure its on, back into space. The panel emits thermal radiation "within the crucial wavelength needed to escape the Earth's atmosphere". The Stanford team went in a different direction compared to other teams attempting to achieve the same goal. They used nanostructured photonic materials to engineer this part of their cooling panel. The material suppresses how much sunlight the panel absorbs, while also radiating it at the key frequency range required to escape the Earth's atmosphere.
The great thing about this cooling panel is that it can be implemented not only in homes and buildings, but also in other structures such as cars. The panel is made up of both a thermal emitter and solar reflector, "making it both higher performance and much more robust and practically relevant." The team believes that this panel can also substitute for solar panels. For example, being placed on a single-family home, it can "offset 35% of its air conditioning needs during the hottest hours of summer," even if it only takes up 10% of the roof.
The cooling panel is mainly passive. You stick it onto your roof, or onto the sides of a building and it starts working. The team believes that this panel will be very useful because many people live in very hot regions of the Earth, causing a rapid rise in electrical demand due to so many air conditioners being used. This panel is both economically and environmentally friendly. It will help people save money on air conditioning bills, and will cool people's homes without the need of using any resources.