United States energy and CO2 savings potential from deployment of near-infrared electrochromic window glazings

Abstract

a b s t r a c tThis paper presents a simulation study of the energy and CO 2 benefits of a transparent, near-infrared switching electrochromic (NEC) glazing for building applications. NEC glazings are an emerging dynamic window technology that can modulate the transmission of NIR heat without affecting transmission of visible light. In this study, a hypothetical NEC glazing is simulated on clear and tinted glass in six building type models in 16 U.S. climate regions using Energy Plus 7.1. The total annual energy consumption for lighting, heating, cooling, and ventilation for the NEC glazings are compared with high performance static windows and conventional tungsten-oxide EC glazings. Using regional CO 2 intensities and building stock totals, the results from individual building model simulations are scaled up to national totals. The U.S. national savings from NEC deployment is found to be 167 TWh/yr (600 PJ/yr) compared to the existing building stock, but only 8 TWh/yr (29 PJ/yr) or 1.56 million tonnes of CO 2 per year when compared to high performance static glazings with lighting controls installed. NEC performance varied significantly by building type and location. This analysis reveals that 50% of the total energy savings can be realized by deploying NEC glazings in only 18% of the total window stock, and 75% of the savings in only 39% of the stock. The best performing locations include medium offices and midrise residential buildings in northern climates, where energy savings per unit window area range from 50 to 200 kWh/m 2 -yr.

Electrochromic materials and devices for energy efficiency and human comfort in buildings: A critical review

“…These properties allow many benefits, as extensively investigated; current studies have focused on energy efficiency [32][33][34][35][36][37][38][39], lowered CO 2 emission [40], and on indoor comfort [41][42][43] for the users of buildings with EC glazing. These assets can be combined with financial benefits for the operators of the buildings [44].…”

Autonomous Light Management in Flexible Photoelectrochromic Films Integrating High Performance Silicon Solar Microcells

“…Selective transmission of visible and infrared (IR) 3 wavelengths facilitates control over lighting and heating/cooling needs, thereby reducing energy consumption. 1,[5][6][7] EC materials have been explored in research since the early 1960s [8][9][10] and their integration into windows intensively examined in the 1980s -early 2000s, [11][12][13][14][15][16] however, widespread commercialization has been frustrated by the need for complicated internal wiring and complete reinstallation of existing windows. 14 PV-powered EC windows are an intuitive solution that utilize incident solar irradiation to power the EC window and circumvent some of the complexity associated with internal wiring.…”

Multistate and On‐Demand Smart Windows

“…When there is excess solar gain or loss through the windows, energy consumption for heating, cooling, and lighting will also increase . As reported in 2012, heating and cooling in buildings account for ≈14% of the total U.S. energy use . Calculations suggest that more than 50% of the energy use for heating, cooling, and lighting could be reduced by deploying optimized glazing window systems .…”

“…As reported in 2012, heating and cooling in buildings account for ≈14% of the total U.S. energy use . Calculations suggest that more than 50% of the energy use for heating, cooling, and lighting could be reduced by deploying optimized glazing window systems . Hence, there has been much effort to develop dynamic (or active) “smart windows” that can be switched between transparent and opaque states through dynamic actuation of optically active materials.…”