Smart glass or switchable glass, is a unique type of glass that is able to change its light transmission properties, based on external stimuli. Smart glass is typically classed into active and passive glass, with active smart glass responding to a user-initiated electrical current, and passive smart glass responding to environmental factors like heat or UV.
Active Smart Glass
Active smart glass requires an electrical stimulus to change its properties. Based on the type of technology used, active smart glass can be categorized into the following types:
Electrochromic Smart Glass
Electrochromic smart glass can change its light transmission rate according to an electrical current. It is transparent before a current is passed through, and becomes translucent or opaque when switched on, although this transition can take some time.
LC Smart Glass
LC and PDLC smart glasses are made by sandwiching a thin layer of liquid crystals between two transparent electrical conductors and laminating this between two layers of glass. Similar to electrochromic glass, PDLC smart glass is translucent before an electrical current is allowed to pass through it. The difference is that PDLC glass has a switching rate of few seconds—much faster than other technologies. LC smart glass is mainly used in the form of privacy glass for skylights, security and commercial displays.
SPD-SmartGlass
SPD-SmartGlass technology uses suspended microscopic particles in the form of a thin layer between layers of glass. It is translucent in the unpowered state and turns transparent when its transmittance is raised because the aligning of particles by the electrical current. The amount of light, glare, and heat passing through the smart glass is controlled by the user.
The primary difference between electrochromic, LC and SPD smart glass is that the latter two require a continuous electrical current to stay in their modified state, and revert back as soon as the power is switched off.
Passive Smart Glass
Passive smart glass changes its properties according to the presence of external stimuli such as heat and light. Based on the stimulus, it can be categorized into the following types:
Thermochromic Glass
As its name suggests, thermochromic smart glass changes its light transmission properties according to the amount of heat absorbed. It is mainly used in self-tinting smart windows to reduce the energy consumption of buildings and control the amount of heat entering a room. Currently, thermochromic smart glass is the most widely used smart glass in architecture because of its low cost and ease of installation compared with other glass.
Photochromic Glass
Photochromic smart glass changes its light transmission properties according to the amount of UV light. It is used in color changing lenses for sunglasses, data storage, novelty items, and super-molecular chemistry; however, its biggest commercial application is in the form of smart windows for architectural glazing.
Because of the huge number of applications for smart glass—everything from car windows, to glazing to regulating heat in new buildings—the market is growing at a pretty exceptional rate, posting a CAGR of 19.19 percent from 2013-2018.
TechNavio analysts have pared down some of the major trends contributing to this impressive growth rate:
Increased Applications in Construction and Architecture
The Global Smart Glass market is witnessing an increase in the usage of smart glass in the Architecture and Construction sector, as buildings with energy saving properties are in high demand.
Currently, the Architecture sector accounts for 11.01 percent of the market— the second largest application area for smart glass globally. However the use of smart glass in this sector is expected to increase at a CAGR of 23.01 percent over the forecast period and will account for 12.89 percent of the smart glass product consumption globally by 2018.
Increased Demand in the EMEA Region
Increased demand for smart glass in Europe, the Middle East and Africa in both the Automotive and Architecture sectors is another major trend that will foster market growth.
The governments in Middle Eastern countries are spending a huge amount on improving the energy-saving and thermal insulation capacities of buildings to attract more tourists. The adoption of larger window sizes and glazing areas in European countries will also boost the demand for smart glass during the forecast period.
Rapid Growth in Usage of Electrochromic Glass
Electrochromic, or electronically switchable glass is popping up in more and more industries, including automotive and aviation. With Boeing opting to use the glass in its 787 carrier, other airlines are expected to follow suit, which will further increase the profile of electronically switchable glass. Though electochromic glass has a slow response speed in comparison to SPD and PDLC glass, it has a longer lifespan, which is a main factor leading to its current popularity.
Application in Solar Panels
The usage of photovoltaic smart glass as a way of increasing the productivity of solar panels will be a major trend during the forecast period. As around 30 percent of potential energy is lost because of dirty solar panels, which in turn reduces the power conversion rate of solar mirrors by 40 percent, the self-cleaning and anti-reflective properties of smart glass can be used to reduce the cost of electricity generation in solar panels.
The commercial use of smart glass in this sector is expected to become more widespread globally in the coming years.
