Cleantech Market Intelligence
In China, Smart Windows Shine Through
Pursuing the long-held goal of turning transparent windows into energy generators, scientists at the Chinese Academy of Science said this week they have developed a window that not only regulates infrared radiation from the sun, but can also act as a collector of solar energy.
The new smart window incorporates vanadium oxide (VO2), which self-adjusts its properties based on temperature; below a certain temperature, it is transparent to infrared light and acts as an insulator; above that point, it becomes reflective. VO2 can also scatter photons to solar cells along the window frame, which can generate power from the ambient light. Published in Nature Scientific Reports, the work has developed a concept smart window device for simultaneous generation and saving of energy,” said co-author Yangeng Gao.
It will likely be years before the smart windows begin appearing in new buildings, but the work highlights the degree to which China is become a center for innovation in smart, energy-efficient buildings. China’s huge building stock continues to multiply: The total area of buildings in China increased from 27.8 billion square meters (m2) in 2000 to 48.6 billion m2 in 2010, according to the Ministry of Housing and Urban-Rural Development (MOHURD). It is estimated that China will add a further 10 billion m2 of commercial and public buildings by 2020. Energy use associated with buildings will increase 70% by then, unless unless energy-efficient building technologies and practices become widespread.
Luminous and Low-Energy
Improving the energy efficiency of new buildings and accelerating the retrofit of existing buildings are two daunting challenges currently facing China. These challenges will be explored in more detail in Navigant Research’s forthcoming report, Energy Efficient Buildings in Asia Pacific.
Already, western firms have begun to realize the enormous opportunity for innovative building design and energy efficiency in China’s buildings sector. This week the American Institute of Architects awarded the Leatop Plaza, a skyscraper that forms a key part of the the Zhujiang New Town, in Guangzhou, a certificate of merit. The 66-floor tower is sheathed in glass shingles that control the sun’s radiation, and it has a tubular structure of diagonal support braces that reduce the need for concrete in the core, adding floor space and making the interior more open and efficient. “The building’s strong presence derives from the simplicity of its form, the clarity of its structural systems and the expressive values of the shingled façade; transparent, translucent, opaque, reflective and luminous.”
Those qualities, not synonymous with China’s buildings sector, will be critical to making China’s buildings smarter and more energy efficient.