Smart Glass and Its Potential in Energy Savings

Abstract

Smart glass is such that its properties may he changed by application of a potential across it. The change in properties may be engineered to alter the amount of heat energy that can penetrate the glass which provides heating and cooling design options. Therein lies its potential in energy savings. Smart glass may be classified into three types: electrochromic, suspended particle, and polymer dispersed liquid crystal (PDLC). Each of these types has their own mechanisms, advantages, and disadvantages. Electrochromic smart glass is the most popular, currently it utilizes an electrochromic film with an ion storage layer and ion conductor placed between two transparent plates. The electrochromic film is usually made of tungsten oxide, owing to the electrochromic nature of transition metals. An electric potential initiates a redox reaction of the electrochromic film transitioning the color and the transparency of the smart glass. Suspended particle smart glass has needle shaped particles suspended within an organic gel placed between two electrodes. In its off state, the particles are randomly dispersed and have a low light transmittance. Once a voltage is applied, the needle particles will orient themselves to allow for light to pass through. PDLC smart glass works similarly to the suspended particle variety. However, in PDLC smart glass, the central layer is a liquid crystal placed within a polymer matrix between electrodes. Similar in behavior to the suspended particles, in the off position the liquid crystals are randomly dispersed and have low transmittance. With the application of a voltage, the liquid crystals orient themselves, thereby allowing for the transmittance of light. These different smart glasses have many different applications, but with one hindrance. The requirement of a voltage source is a major disadvantage which greatly complicates the overall installation and manufacturing processes. However, the integration of photovoltaic (PV) devices into smart glass technology has provided one solution. Photovoltaic films attached in the smart glass will provide the necessary voltage source. The photovoltaic film may even be designed to produce more voltage than needed. The use a photovoltaic smart glass system provides significant cost savings in regards to heating, cooling, lighting, and overall energy bills. Smart glass represents a technology with a great deal of potential to reduce energy demand. Action steps have been identified to propagate the popular use of smart glass.

Evaluation of Impact of Shading Devices on Energy Consumption of Buildings in Tropical Regions

“…The overhang creates a shadow on window (h) and that depends upon the overhang width {D), solar altitude, solar azimuth, and window azimuth angle h-Dx tan(solar altitude)/ cos (iolar azimuth -window azimuth) (6) Thus, solar altitude is a very important factor in shading. As discussed in Ref.…”

“…Therefore, development of smart energy saving technologies for buildings, such as in Ref. [6] is important in this context. Building models are being increasingly used to simulate and study conditions and inventive techniques that would reduce energy demand and ensure optimum indoor comfort conditions.…”

Low power driving techniques for 1-pixel displays

“…One of them is smart glass [8]. A major disadvantage of smart glasses, their requirement for a voltage source, can be resolved by the addition of photovoltaic devices [8], but lower power consumption is still desired.…”

Low-Power Driving Technique for 1-Pixel Display Using an External Capacitor

“…Application examples of large smart glasses include architectural glass, automobile, and aircraft [13]. A major disadvantage of the smart glass, the need for a voltage source, can be resolved by the integration of photovoltaic (PV) devices [12], [13], which means lower power consumption is desirable. PDLCD [14], one type of smart glass, is often used to realize electrically controlled privacy glass thanks to its scattering property [15].…”

“…Unlike multi-pixel LCDs, 1-pixel LCDs, the target of the proposed technique, are used in far more applications than just information display. One of them, the smart glasses, takes three different approaches: electrochromic glass, suspended particle glass, and LC glass [12]. Application examples of large smart glasses include architectural glass, automobile, and aircraft [13].…”