Researchers Develop Self-Powered Smart Window Technology for Cost-Effective Alternatives

The device leverages unique materials and design to switch from transparent to coloured states seamlessly, controlling visible and near-infrared light to reduce indoor temperatures and power consumption significantly.

Recent studies at the Centre for Nano and Soft Matter Sciences (CeNS) have led to the development of an innovative smart window technology that eliminates the need for external electrical power while being highly cost-effective. Spearheaded by Dr. Ashutosh K. Singh, this breakthrough addresses the challenges faced by traditional electrochromic windows, which require external power and are typically limited to costly and intricate production processes.

These self-powered electrochromic windows, backed by the Department of Science and Technology (DST) under the Advanced Materials Technology initiative, offer a solution that not only stores its own operational energy but also maintains consistent energy-efficient performance. The device leverages unique materials and design to switch from transparent to coloured states seamlessly, controlling visible and near-infrared light to reduce indoor temperatures and power consumption significantly.

First Study: Self-Powered Electrochromic Window Innovation

The first study, recently published in Small, details a self-powered electrochromic (RP-SPEC) smart window that relies on redox potential and integrates an energy storage capability. The design employs tungsten oxide (WO₃) as the electrochromic film, combined with vanadium-doped nickel oxide (V-NiO) and an aluminum anode on a single tin-doped indium oxide (ITO) layer. By generating power through an internal electrochemical reaction, the device eliminates dependency on external sources and allows for high color opacity and effective light modulation.

Switching performance is substantial: the device can transition between transparent and colored states over 2,000 cycles and achieves an impressive 88% light modulation at a 550 nm wavelength, an improvement over current electrochromic technologies. Additionally, it attains a voltage of 1.1–1.7 V depending on the state, ensuring sufficient power for operation in even remote applications.

Second Study: Affordable, Industrially Scalable Manufacturing

The second study, published in the Journal of Materials Chemistry C, introduces an economical, scalable spray-coating method for producing smart windows, making the technology accessible for broader applications. Utilizing WO₃ and NiO, the method yields devices with 67% optical contrast and switch times of 10 and 17 seconds for coloring and bleaching, respectively. This technique avoids the multi-step processes used in conventional methods, substantially reducing production costs and ensuring high colouration efficiency.

“The new electrochromic smart windows represent a pivotal advancement for sustainable infrastructure. By enhancing both energy efficiency and affordability, these devices can revolutionize how buildings manage light and temperature,” noted Dr. Ashutosh K. Singh. The CeNS team continues to refine the technology, positioning it as a key component in India's broader strategy for energy efficiency and renewable energy integration.

With their dual studies, Dr Singh and his team aim to transform India’s architecture into a greener, more cost-efficient landscape, addressing both environmental concerns and practical energy solutions. These innovations in smart window technology hold promise for extensive applications, from urban residential and commercial buildings to remote infrastructure in challenging climates.