Electrochromic Film for More Efficient Windows

Electrochromic Film for More Efficient Windows

OPEN 2009
Littleton, Colorado
Project Term:
01/01/2010 - 06/30/2013

Critical Need:

Buildings account for 40% of all energy used in the U.S., and windows alone are responsible for 25% of the energy consumed by a typical building. Electrochromic windows can reduce cooling requirements in summer and heating requirements in winter by applying electric current changes the window's color, and thereby its heat transmission properties. The primary challenge to broader adoption is the high cost resulting from small-scale manufacturing of electrochromic film onto rigid surfaces.

Project Innovation + Advantages:

ITN Energy Systems is addressing the high cost of electrochromic windows with a new manufacturing process: roll-to-roll deposition of the film onto flexible plastic surfaces. Production of electrochromic films on plastic requires low processing temperatures and uniform film quality over large surface areas. ITN is overcoming these challenges using its previous experience in growing flexible thin-film solar cells and batteries. By developing sensor-based controls, ITN's roll-to-roll manufacturing process yields more film over a larger area than traditional film deposition methods. Evaluating deposition processes from a control standpoint ultimately strengthens the ability for ITN to handle unanticipated deviations quickly and efficiently, enabling more consistent large-volume production. The team is currently moving from small-scale prototypes into pilot-scale production to validate roll-to-roll manufacturability and produce scaled prototypes that can be proven in simulated operating conditions. Electrochromic plastic films could also open new markets in building retrofit applications, vastly expanding the potential energy savings.

Potential Impact:

If successful, ITN's roll-to-roll processing technique would lower the cost of electrochromic windows to the point that building developers will use them in new installations and in retrofitting existing buildings, reducing heating and cooling costs up to 40%.


Improving the energy efficiency of our buildings reduces pressure on the electrical grid, improving its stability.


Improvements in heating and cooling efficiency can save homeowners and businesses thousands of dollars on their utility bills.


Improvements in heating and cooling efficiency could save homeowners and businesses thousands of dollars on their utility bills.


ARPA-E Program Director:
Dr. Mark Johnson
Project Contact:
Dr. Brian Berland
Press and General Inquiries Email:
Project Contact Email:


MAG Industrial Automation Systems, LLC
Esgee Technologies, Inc.
Electric Power Research Institute, Inc. (EPRI)

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