Smart window technology that automatically changes color by sunlight
Secured smart window technology that controls the visible light transmittance depends on the intensity of sunlight. Cheaper than existing electrochromic windows and can be applied to automobiles as well as buildings through filming technology.
Credit: Korea Institute of Energy Research (KIER)
The original technology of smart window that can automatically adjust the amount of sunlight entering the room by changing the color of window depends on the intensity of sunlight has been developed by a domestic research team.
The research team of Dr. Han Chi-hwan of Korea Institute of Energy Research (KIER) succeeded in developing the smart window technology which does not need power by inserting a light absorbing layer that can generate electromotive force into an electrochromic device. This new smart window technology can lower the price by 30% to 50% or more comparing to existing products.
The light-sensitive automatic color conversion smart window technology combines solar cell technology and electrochromic technology. It can simultaneously solve the need for a separate power supply and high production cost which are the disadvantages of the existing electrochromic technology. In addition, it can control the intensity of sunlight and dramatically reduce the energy used for lighting by 30% to 40% or more as a future smart window technology.
The existing electrochromic smart window products were not revitalized in the market due to expensive price and the difficult construction for connecting electric wiring to window. However, since the photosensitive automatic color conversion smart window technology contains a light absorbing layer in the device, there is no need for a separate power supply, and it can also reduce the price because it does not use expensive conductive glass during production.
The light-sensitive automatic color conversion smart window has better ability to block sunlight when it is stronger, so it can be applied to large buildings with high cooling costs by blocking visible light as well as IR light transmission in summer. In addition, this excellent technology does not require a separate power supply, and it can be applied to existing buildings that makes market expandability.
The research team has succeeded in developing not only the glass but also filming technology, and they are also making a product that can attach to and detach from existing window glasses. If the development of film-type products is successful, it is expected to expand not only to buildings, but also to various markets such as automobiles, ships, and aircraft.
Dr. Han Chi-hwan, researcher of the photovoltaics research department of KIER and the head of this project said, “As the government has established a road map that obligates zero-energy buildings step by step since 2020, this photosensitive automatic color conversion smart window technology has the effect of blocking heat when sunlight is strong, so it can improve the energy efficiency when applied to a zero-energy building. It is also expected to contribute to the construction of a future smart city by combining solar cell technology and electrochromic technology into one.”
This technology development was carried out as a part of the future leading technology development project supported by the Korea Research Foundation. There was a technology transfer signing ceremony with NES4U for the ‘Patent and know-how on light-sensitive automatic color conversion technology’ at the Korea Institute of Energy Research on March 2.
Meanwhile, NES4U plans to develop a photo-electrochromic smart window and film by combining its own ‘electrochromic technology’ and ‘photosensitive automatic color conversion technology’ transferred from the Korea Institute of Energy Research and commercialize to the film market for attaching on large commercial buildings and automobiles.