Website ubiquitous.energy Type of business Private | Founded 2011 | |
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Headquarters Redwood City, California, United States Founders Richard Lunt, Vladimir Bulović | ||
Transparent solar cells solar windows by ubiquitous energy
Ubiquitous Energy, Inc. is an American solar energy startup company headquartered in Redwood City, California that designs transparent solar technology to absorb ultraviolet and near infrared light (NIR) (wavelength span of λ= 650– 850 nm) while transmitting visible light through its medium called ClearView Power TM. Ubiquitous Energy is a privately funded company founded in 2011 by Miles Barr, Vladimir Bulović, and Richard Lunt. Current solar power is created in solar plants that take up lots of surface area far away from where the energy is consumed. It is estimated 15% of the energy is lost during distribution. Ubiquitous Energy's technology allows large cities to be solar plants themselves by converting the windows on buildings into solar energy generators. Ubiquitous Energy is implementing its ClearView Power TM technology into a wide range of products as an invisible, onboard source of electricity. Some examples of these implementations include mobile devices, windows, an digital signage.
Contents
Technology
Previously, transparent solar technology was made by trying to shrink the components of the solar cell itself or segmenting inorganic solar cells across the module area, but this comes with limitations and doesn't achieve true transparency. Rather, Ubiquitous Energy focuses on organic solar cells and which light is being absorbed. Developed from research done at Massachusetts Institute of Technology (MIT) they have developed organic photoactive materials (organic photovoltaics, OPVs) that allow visible light to pass through its technology but selectively absorb the light from the invisible part of the spectrum, near infrared (NIR) and ultraviolet (UV) light. They call this technology ClearView power TM. ClearView Power TM is an invisible film less than 1/100th of a millimeter thick that can be put onto any surface and generate energy without with out affecting the material beneath it. Specifically they are trying to capture all of the photons of ultraviolet and infrared light while allowing the photons of visible light to pass through. Once energy is created from the OPVs, it is able to be harvested through dye-sensitized solar cells (DSC) containing electrodes as electron emitters and iodide/tri-iodide redox electrolyte as an entire transport layer.
Utilizing advancements in nano-structured photovoltaic (nano-PVs) device architecture has led to the improvement in power conversion efficiency (PCE) needed to make transparent solar cost effective. The nano-PV solar cell class includes a variety of solar cells including molecular, organic, polymeric, dye-sensitized, and colloidal quantum dot (CQD) PVs. As light passes throughout the transparent solar cell NIR is absorbed, then with the incorporation of NIR reflecting mirrors, there is better PCE and optimization of performance.
The OPVs are made on glass, pre-coated with 150 nm thick idium-tin oxide (ITO). Then 20 nm Molybdenum trioxide (MoO3), 15 nm chloroaluminum phthalocyanine (ClAlPc), 30 nm Buckminsterfullerene (C60), 7.5 nm bathocuproine (BCP), and 100 nm thick Ag cathode are added through thermal evaporation. This combination of layers allows for better absorption of different types of light that are otherwise not being used.
As light passes throughout the transparent solar cell the NIR is absorbed, then with the incorporation of NIR reflecting mirrors, a higher PCE is achieved optimizing performance. To produce, and carry the electricity, out of the cell, a typical transparent photovoltaic device will have UV and NIR active layers that, when exposed to sunlight, interact with each other to create and electric field causing an electrical current to flow. The UV and NIR active layers are then sandwiched by layers of electrodes that are connected to an external circuit which carries the current out of the device.
Future Goals
The current development of the solar cells is transmitting approximately 70% of visible light and has a power conversion of approximately 2%. Researchers think that realistically they should be able to reach over 12% power conversion efficiency while still transmitting visible light with there are theoretical limits above 20%.
Costs and Benefits
Exact cost of installing and implementation of this technology varies with each application, however, the process of fabrication does not use as much energy as other methods and is much more environmentally friendly, driving the cost down. Additionally, because the film can be applied to any surface, it is able to be implemented into the cost of construction projects very easily. Simply putting the film in between panes of double-paned windows protects it from the elements and drastically lowers installation costs because there is no external hardware needed.
The limitations of photovoltaic cells create issues not only with the PCE but creates issues with cost and feasibility of manufacturing this type of solar technology to the industrial scale. These limitations include: 1) the incomplete absorption of the entire light spectrum, 2) thermalization of hot carriers in the form of excess heat, 3) chemical potential (thermodynamic) losses, and 4) radiative recombination. Reducing the effects of these limitations allows for a better PCE and lower cost.
Mobile Devices
Ubiquitous Energy sees its main marketplace in mobile devices. Previous efforts to turn the surfaces of mobile devices into solar panels were limited due to the focus on high-performance displays. The sacrifices that would have to be made to the displays themselves to allow them to produce energy were not seen as feasible at the time. However, Ubiquitous Energy is able to apply their film to the surface of tablets and phones making them self sustainable and hypothetically eliminating the battery entirely. Additionally, the ClearView PowerTM film doesn't impact the device's aesthetics nor the performance of the display.
Windows
Another marketplace Ubiquitous Energy sees potential is on windows. Smart Glass, as its called, allows for buildings to balance their energy usage and save money in the process. for example, assuming 5% PCE, the power generated from turning all of a buildings windows into solar generators could fulfill more than a quarter of the buildings electricity needs.
Digital Signage
Ubiquitous Energy also sees use of their technology in internet of things. One application that they sight is applying their technology to digital signage. This could include self-sustaining road signs to electronic shelf labels. As price tags are being replaced with electronic shelf labels, ClearView PowerTM allows for dynamic pricing as supply and demand is continuously changing because there is minimal maintenance required other than the programming of the labels themselves.
Competitors
Onyx Solar, a Spanish solar company founded in 2009, would be Ubiquitous Energy's closest competitor. Their focus is on integrating solar energy photovoltaic into buildings and they produce photoactive glass to produce energy. Different from Ubiquitous Energy's film, they have to manufacture the glass or photovoltaic structure making it similar to any construction project and it is not as transparent as the film created by Ubiquitous Energy. However, they have several projects done already whereas Ubiquitous energy is still developing a mass market prototype as of 2015. Although they are both competing in the solar industry, the focus of Onyx Solar is oriented toward buildings whereas Ubiquitous Energy looks more toward mobile devices as its main marketplace.