MIT startup reported in 2013. Now the universal energy is getting closer to bringing its transparent solar window blinds to market. Lunt cofounded the company and remained an assistant professor of chemical engineering and materials science at Michigan University. They are changing the way the cell absorbs light from shrinking the components. Instead, the cell selectively takes the part of the solar spectrum that we cannot see while letting regular visible light pass.
What are solar window blinds, and how do they work?
A solar window blind is any technology that uses windows on buildings to produce electricity from the sun. Several technologies are there that could hit the mass market soon.
Transparent solar windows blind would hypothetically be able to replace standard glass window panes. They are traditional solar panels, and technology is often referred to as “building-integrated photovoltaics or BIPVs. BIPV technologies are open to many potential benefits. Many people love them as they are much more aesthetically appealing and easy-to-maintain than traditional solar options. But this depends on the type of installation.
Let us dig up more…
Transparent solar windows blind is something of an oxymoron. Solar cells, precisely the photovoltaic kind, make energy by absorbing photons from the sunlight and converting them into electrons. If a material is transparent, all the light passes through the medium to strike your eye’s back. Therefore, previous translucent solar panels have only been partially transparent. To reduce the risk of injury, they cast a colorful shadow in solar window blinds.
To overcome this limitation, Michigan State researchers use a slightly different technique for gathering sunlight. They have used a transparent luminescent solar concentrator (TLSC) instead of creating a transparent photovoltaic cell. The TLSC consists of organic salts. And also, it absorbs specific invisible wavelengths of ultraviolet and infrared light. Then they glow as another wavelength of infrared light. The infrared light is emitted by it. The light then forwarded to the plastic’s edge, which are thin strips of the conventional photovoltaic solar cell. And then, it converts it into electricity, and at the same time, it performs as a solar window blind.
In an interview with Today blog, Lunt said that the blinds open a lot of areas to station solar energy in a non-intrusive way. He further said that they could use the blinds on tall buildings with lots of windows. Also, in any mobile device that demands high aesthetic quality like a phone or e-reader. The team’s ultimate goal is to make solar harvesting surfaces that people do not even know exist.
The ubiquitous energy is confident that the technology can be scaled from enormous industrial and commercial applications and down to consumer devices while remaining affordable. It would be friendly to produce large amounts of solar power from glass and plastic sheets as they seem like typical sheets of glass and plastic.
Other Solar technologies Vs. the upcoming transparent solar windows
It is challenging to invent a new solar technology that commercially competes with today’s solar cells and existing deployment methods. But a transparent photovoltaic cell would change it. We can station them on any surface without disturbing the look of the underlying material. Users will be able to use whatever pattern they want underneath as the cells that sit on top are invisible. They could be on everything around us, including our windows, and we would never notice it.
Most of the other research groups have previously worked on making “see-through” window – solar window blinds, usually by taking conventional opaque PV materials. They have either made the material thin to make it translucent or divided… But those things involve an inherent trade-off between transparency and efficiency. When the process starts with opaque PV materials, they typically have to decrease the amount of active area to increase transparency. According to Miles Barr, Ph.D. ’12, president and CTO of Ubiquitous Energy, Inc, with existing PV technologies, it is impossible to optimize for aesthetics and efficiency at the same time.
Solar window blinds would hit a record of 8% efficiency.
In August 2014, the team took a step closer to skyscrapers that serve as power sources. Researchers at Michigan State University set a new efficiency record for the color-neutral, fully transparent solar concentrator. This could turn any window or sheet of glass, like your mobile phone screen, into a photovoltaic solar cell. This item is not like other “transparent” solar panels that we know from the past. According to Richard Lunt, the lead researcher, the team was sure that the transparent solar panels could be efficiently stationed in a wide range of settings. They said that they achieved 43.3 percent transparency with their organic and carbon-based design rather than conventional silicon.
The team achieved 8.1% efficiency and 43.3% transparency with the organic, carbon-based design rather than conventional silicon. The researchers said that the cells seem to be a slight green tint. But they are much more like the gray of sunglasses and vehicle windows. Today’s best commercially available solar panels achieve just over 22 percent efficiency. Eight percent may not like an impressive figure on paper. This percentage is without the loss of the light spectrum emitted from transparency.
Windows, which is common in every building, is the best location for organic solar cells. They offer something silicon cannot do, a combination of high efficiency and high visible transparency. This is Professor Stephen Forrest’s opinion, who led the research.
There is a coating on buildings with glass facades, and typically they reflect and absorb some of the light. It absorbs both in the visible and infrared parts of the spectrum, and it enhances to reduce the heating and brightness inside the building.
The magical material
Transparent solar window blinds could facilitate the building’s electricity needs rather than throwing that energy away. The transparency of some of the existing windows is somewhat equal to the clarity of the solar cells. Forrest’s group reports reported this in the journal Proceedings of the National Academy of Sciences.
The research team developed a magical material. The material and structure of the device had to perform multiple tasks. Balance numerous trade-offs, high voltage, high current, low resistance, and color-neutral transparency all at the same time, to name a few.
The new material is a collection of organic molecules engineered to be transparent in the visible and absorbing near-infrared. The part that invisible in the spectrum consists of much of the energy in sunlight. Optical coatings are there to boost both powers generated from infrared light and transparency in the visible range. These two qualities are usually in competition with one another.
The color-neutral version of the device is composed of an indium tin oxide electrode. A silver electrode maintained the efficiency to 10.8 percent, with 45.8 percent transparency. But the slightly greenish tint of that version may not be acceptable in some window applications. But the team can manufacture both these versions on a large scale. They contain materials that are less toxic than other transparent solar cells.
Not only the composition, but the placement matters too!
The best advantage is that they are most efficient when the sun rays are hitting them at a perpendicular angle. The transparent organic solar cells can be placed in between the panes of double-glazed windows and customized for local latitudes.
Forrest and the research team are now working on several improvements to the technology. Their next goal is to reach a light utilization efficiency of 7%. Moreover, they hope to extend the cell lifetime to about ten years. Not only that, but they are also investigating the economics of installing transparent solar window blinds into new and existing buildings.
Why is there no solar window blinds technology seen everywhere?
The answer is functionality.
Traditional solar panels use photovoltaic technology. It means that they capture energy in the form of light to generate electricity. It is because windows should let less light go through them. Windows and window blinds that act as solar panels need to let incoming light illuminate a room. Then at the same time, it should also capture incoming light to use for energy production. A solar window that does not let enough light acts as a vertically mounted solar panel. If it gets too much light in, the window cannot generate enough electricity to be cost-effective. For solar window blinds to impact the solar market, they need to become genuinely building-integrated and unobtrusive by utilizing transparent solar panel technology.
Researchers have recognized that this technology is unable to provide the entire emission-free energy requirement. But of course, they can be a part of the journey by contributing as a green energy solution. It has space for more improvements to not require making vast new areas to collect solar energy. With this technology, advanced solar window blinds will exist on surfaces all around us soon.