SAGE Electrochromics, Inc. headquarters in Faribault, Minn.

This is a pretty strong endorsement: Saint-Gobain Glass has acquired 50 percent of the equity of Sage Electrochromics for the large-scale manufacture of electrochromic glass.The $80 million investment will enable construction of the world’s largest and most advanced electrochromic glass manufacturing facility in Faribault, Minn.

We first wrote about Sage back in March when the company received a $72 million DOE loan guarantee, i.e., the DOE serves as a financial backstop for an investor, and now it looks like Saint-Gobain’s will be the source for those monies.

Activated by a low-voltage current, Sage’s electrochromic glass adapts its light and heat transmission – and so its tint – to the level of sunlight and the building’s ambient temperature, without hindering external visibility. The Lawrence Berkeley National Lab says SageGlass could cut a building’s heating and air conditioning equipment size by up to 25% and reduce overall cooling loads for commercial buildings up to 20% (by lowering peak power demand) besides shrinking lighting cost. Use of SageGlass may provide LEED credits.

According to a Saint-Gobain press release (PDF), the new plant will have an annual production capacity of more than 370,000 square meters of electrochromic glass with sizes ranging up to 5 x 10 feet, much larger than currently available in the market. The plant is scheduled to begin production starting in mid-2012.

The announcement takes place one year after Saint-Gobain launched its Quantum Glass brand.

“This alliance heralds the start of a new revolution in the habitat glass industry,” said Jean-Pierre Floris, senior vice president of Compagnie de Saint-Gobain and president of the Innovative Materials Sector. “Thanks to the partnership between Saint-Gobain and Sage, we are providing electrochromic advanced glazing that will be environmentally significant and affordable.”

Sage uses a vacuum-deposition sputtering process coating conventional float glass. A second piece of glass is added to complete the sandwich, which is surrounded by an aluminum frame. The units can transmit less than 4% of the visible light in their tinted state.

According to a Sage press release (PDF), Sage will remain an independent company and continue to market its SageGlass products in North America. Saint-Gobain will market SageGlass under the Quantum Glass brand in Europe. The two companies will work together to develop a marketing strategy for Asia and the rest of the world, leveraging Saint-Gobain’s distribution partnerships.

“Until now, electrochromic glass has been an emerging product, not widely deployed due to cost and manufacturing challenges. This alliance will trigger economies of scale, making possible a new era of high-performance windows that are both eco-friendly and economically sound,” says John Van Dine, Sage CEO.