Smart glass adds up to energy savings

  • Article by: STEVE FISCHER , Star Tribune
  • Updated: February 22, 2014 - 2:00 PM

RiverCentre aims to get better control of its boardroom environment – and its energy costs – with variable-tinted windows from Sage Electrochromics of Faribault.


RiverCentre in St. Paul has installed windows built by Sage Electrochromics of Faribault in the boardroom. The glass lightens and dims with the use of a control panel.

Photo: Bruce Bisping •,

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For years, visitors to the St. Paul RiverCentre’s boardroom have sweltered from heat buildup from the summer sun. To solve this problem, the center installed “smart glass” windows last month — 26 in all — that can be tinted depending on the level of sun.

The installation is part of the RiverCentre’s three-year sustainability plan, nicknamed “80-20 in three.” The plan began in April 2010 to reduce the conventions center’s carbon footprint by 80 percent and become 20 percent more efficient than an average building of like size.

Jim Ibister, RiverCentre general manger, said the new windows will lower the cost to cool the room in the summer and manage sunlight better in the winter.

The high-tech windows are the most recent — and most visible — example of energy-saving improvements designed to meet the center’s ambitious energy agenda.

“We think we will hit [the goal] this year, though we will be a few months behind,” Ibister said.

The windows, manufactured by Sage Electrochromics in Faribault, Minn., can be set to automatically switch from four set points of tint. This is expected to prevent the heat buildup during the summer, saving energy in the process. The energy-saving feature of the windows is their thin ceramic coating, which tints the glass when activated by a current of low-voltage electricity.

Derek Malmquist, Sage Electrochromics vice president of marketing, said “the project is a retrofitting. The building and room already existed, we came in to correct a problem.”

Global initiative

The RiverCentre’s sustainability plan is one local example of a global initiative to rein in pollution and reduce energy consumption in commercial and industrial buildings.

This month, Maplewood-based 3M Co. joined Sage Electrochromics in an international clean-energy consortium between the U.S. and China. The consortium, which was launched in 2009 by President Obama and Hu Jintao, then president of China, is called the U.S. China Clean Energy Research Center.

Each country, through public and private funding, contributed $75 million to the fund, in hopes of facilitating “joint research and development on clean-energy technology.”

The consortium estimates that in the next 20 years, China will build more square footage of floor space than the current total in the United States. The goal to make those buildings as energy efficient as possible.

“Both countries,” the consortium says, “have large domestic coal reserves and use coal to generate the majority of their electricity [roughly 50 percent in the U.S. and 80 percent in China].”

In 2012, Sage Electrochromics hired an executive to manage its operations in China.

“As China continues to build out its urban centers, architects and building owners are looking for a balance of sustainability and energy efficiency while still advancing bold designs with an abundant use of glass,” the company said in a statement at the time.

Pike Research, which studies emerging technologies for international companies, estimates that the market value of smart glass will reach at least $700 million by 2020.

In line with the expansion of the smart-glass market, Sage Electrochromics recently opened a new $150 million factory in Faribault, positioning itself to ramp up sales of its variable-tint glass in the United States.

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