We use cookies to improve your experience and for marketing. Read our cookie policy or manage cookies.
Search across reports, market insights, and blog stories.
A novel type of smart window has been developed by researchers at the City University of Hong Kong, as reported by pv magazine. The system combines a thermochromic hydrogel layer with bifacial solar cells to manage solar heat and generate electricity simultaneously.
The thermochromic technology allows the glazing to change its optical properties based on temperature. The hydrogel layer shifts from transparent to translucent as temperatures rise, reducing solar heat entering a building. A key innovation is the bifacial photovoltaic component, which captures solar energy from both sides. This design specifically harvests light reflected by the hydrogel when it is in its hot, translucent state, addressing a common limitation where that energy would otherwise be wasted.
The prototype system is constructed with a bifacial photovoltaic glass pane on the exterior, an air gap, and an interior pane containing the hydrogel layer. This configuration allows for independent maintenance of each component. Experimental testing on a summer day demonstrated several performance benefits. Compared to thermochromic glazing alone, the hybrid system reduced direct solar heat gain by an estimated 30% and lowered indoor air temperature by several degrees. When compared to conventional bifacial photovoltaic glazing, it reduced direct solar heat gain by approximately 62.6%, lowered indoor temperature more significantly, and increased electricity generation by about 16.5%.
Annual simulations for tropical climates indicate the system provides a higher bifacial energy gain compared to standard bifacial photovoltaic units for both skylight and vertical window installations. The simulations also show substantial reductions in annual indoor heat gain for both application types when compared to either standard bifacial photovoltaic or thermochromic glazing alone. The researchers identified the ratio of photovoltaic cell coverage and the specific transition temperature of the hydrogel as critical design parameters for optimizing performance.
The system is described as a passive, scalable solution for improving building energy efficiency in warm climates, aiming to lower cooling demands while boosting on-site power generation. The findings were detailed in the academic journal Building and Environment.
Making Data-Driven Decisions to Grow Your Business
A Quick Overview of Market Performance
Understanding the Current State of The Market and its Prospects
Finding New Products to Diversify Your Business
Choosing the Best Countries to Establish Your Sustainable Supply Chain
Choosing the Best Countries to Boost Your Export
The Latest Trends and Insights into The Industry
The Largest Import Supplying Countries
The Largest Destinations for Exports
The Largest Producers on The Market and Their Profiles
The Largest Markets And Their Profiles
Instant access. No credit card needed.
Online access to 2M+ reports, dashboards, and tables. Trusted by Fortune 500 teams.
IndexBox, Inc.
2093 Philadelphia Pike #1441
Claymont, DE 19703, USA
Contact us
© 2026 IndexBox, Inc
Instant access. No credit card needed.
Online access to 2M+ reports, dashboards, and tables. Trusted by Fortune 500 teams.

source