At last there’s a new development in smart windows giving me fresh hope that I will see these in my lifetime. From the Sept. 6, 2011 news item on Nanowerk,
Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have unveiled a semiconductor nanocrystal coating material capable of controlling heat from the sun while remaining transparent (“Dynamically Modulating the Surface Plasmon Resonance of Doped Semiconductor Nanocrystals”). Based on electrochromic materials, which use a jolt of electric charge to tint a clear window, this breakthrough technology is the first to selectively control the amount of near infrared radiation. This radiation, which leads to heating, passes through the film without affecting its visible transmittance. Such a dynamic system could add a critical energy-saving dimension to “smart window” coatings.
“To have a transparent electrochromic material that can change its transmittance in the infrared portion of sunlight is completely unprecedented,” says Delia Milliron, director of the Inorganic Nanostructures Facility with Berkeley Lab’s Molecular Foundry, who led this research.
These kinds of coatings offer substantive energy savings. A lot of people don’t realize that buildings account for approximately 40% of the carbon emissions in the US. A smart window could theoretically lower the use of air conditioning and lighting by as much as 49% and 51% respectively according to the authors of the news item. I have seen similarly high numbers elsewhere so I am inclined to believe them.
Here’s what I think is the nifty part,
“Traditional electrochromic windows cannot selectively control the amount of visible and near infrared light that transmits through the film. When operated, these windows can either block both regions of light or let them in simultaneously,” says Guillermo Garcia, a graduate student researcher at the Foundry. “This work represents a stepping stone to the ideal smart window, which would be able to selectively choose which region of sunlight is needed to optimize the temperature inside a building.”
And then there’s the robot,
“Our ability to leverage plasmons in doped semiconductors with a very sensitive switching response in the near-infrared region also brings to mind applications in telecommunications,” Milliron adds. “We’ve also brought this synthesis into WANDA, our nanocrystal robot, which means we will be able to provide materials for a wide variety of user projects. “
I don’t see anything which indicates when this might be commercially available.
This latest development reminded me of Switch Materials, the Canadian smart window company that’s located in the Vancouver region. I last wrote about them in my May 14, 2010 posting and thought I’d check them out again. They have a new look on their website and a number of headings for different categories of purchasers such as architects, manufacturers, owners, etc. There’s also a list of the various media outlets that have featured the company. Strangely, there’s no mention of any customers and other than a very general description heavily weighted towards the advantages of the technology I was not able to find much detail about the technology. That’s also true of the news item but I expect more from a company website, especially a company offering an emerging technology. Finally, I was not able to discover how to purchase the product other than contacting a general phone number or sending a general inquiry to firstname.lastname@example.org.
Tags: Canada, Delia Milliron, Dynamically Modulating the Surface Plasmon Resonance of Doped Semiconductor Nanocrystals, electrochromic windows, Guillermo Garcia, Lawrence Berkeley National Laboratory, Molcular Foundry, photochromic windows, plasmons, smart windows, SWITCH Materials, US Dept. of Energy, WANDA, windows