Composite coatings using nanocrystals are now able to selectively block out heat and light.
The next step in intelligent glass
To date, smart glass has played a role in very specific applications across sectors including the construction and automotive ones. Europe’s ICE 3 high-speed trains, for example, use electrochromic glass panels between passenger compartments and drivers’ cabins.
Now, thanks to breakthrough scientific research, smart glass technology appears ready to transform the performance of the buildings we live and work in – as well as turn the dial on the enormous energy and carbon challenges we face.
Realizing dynamic and independent solar spectrum control
Image Credit: Creative Services, Lawrence Berkeley National Lab.
Revolutionizing window efficiency
Led by chemist Delia Milliron, researchers at the Berkeley National Laboratory in California have realized a critical new energy-saving dimension in smart window coatings, as published this month in ‘Nature’ science journal. In the words of lab scientist Howdy Goudey: “Smart windows have the potential to dramatically reduce the energy use associated with windows by adjusting to the optimal properties under all environmental conditions.”
With previous technology, blocking heat meant also darkening the glass. Now, three-state performance enables flexible switching between bright, cool and dark – transparent, heat-blocking as well as combined heat- and light-blocking glass.
Perfecting the fine art of flat glass production - uniting automation and power for manufacturing excellence
Image Credit: Siemens AG
The research breakthrough means it is possible for the first time to control near-infrared light (causing heat) and visible light independently of each other. Interaction between two highly conductive materials – nanocrystals of indium tin oxide and a glassy matrix of niobium oxide – leads to a much greater blocking effect than before. As Milliron puts it: “From a materials-design perspective, we’ve shown that you can combine very dissimilar materials to create new properties that are not accessible in a homogeneous single phase material.”
Caption “dark_bright films”: Adualband electrochromic materialhas been developed by linking tindoped indium oxide nanocrystals to an amorphous niobium oxide matrix. These transparent films are capable ofblockingsolar radiation in a controlled fashion, allowing daylight and solar heat to be selectively and dynamically modulated through windows.
Image Credit: Anna Llordés, Lawrence Berkeley National Lab
The efficiency payoff
A small electrical range of 2.5 volts enables this chemical reaction, while the new glass retains 96% of its charge capacity even after being switched on and off over 2,000 times. As full commercialization waits on further optimization and stability improvements, the potential payoff for wide scale deployment is enormous.
The universal smart glass concept has the power to block 50% of heat and 70% of light. And with residential and commercial buildings accounting for 40% of energy consumption and 30% of energy-related carbon emissions in the US alone, advanced glass technology looks to play a key role in tomorrow’s sustainable infrastructures.
Integrating automation and power with a glass pioneer
For its part, Siemens shares 150 years in the glass industry, with groundbreaking inventions such as the regenerative furnace developed by Friedrich Siemens in 1856 still active principles in the sector. Glass is not only one of the oldest industries in the world, it’s also one of the most energy-intensive manufacturing disciplines.
Innovative technologies from Siemens – such as waste heat recovery solutions that generate up to 60% of plant requirements or plant-wide automation and power integration – help to transform energy and resource performance for glass manufacturers. We support advanced coating innovation in the flat glass segment, while also helping to re-invent building efficiency and comfort when it comes to urban environments.
Transformations to come
Switchable windows that are dynamically flexible to time of day and season will become a core component of industrial glass innovation as well as intelligent urban infrastructures. We look forward to the transformational potential to come in this universal material.