Smart Windows with Electrochromic Film: Almost Ready for Prime Time

Estimated reading time: 3 minutes

How much do you expect the technology to cost? How competitive will it be with existing technologies (e.g. price/performance)?

We target a price level of 200 €/m2, which is about a factor of 4 less than standard EC windows based on glass. To be really competitive, an even lower price may be required, but 200 €/m2 is usually discussed in the community as a threshold price for competitiveness. A full performance evaluation is currently in progress. According to discussions with potential end-users, producers and customers, price is the major driver, while some performance aspects may be negotiable, depending on the application.

How easy or difficult will the technology be to commercialise?

It is a complex process presumably requiring an industrial development phase of 2-3 years after the end of the project and substantial investment (currently estimated: €10 million).

Which are the most promising application areas?

Smart windows for energy-efficient buildings, vehicle sunroofs, smart aircraft cabin windows, switchable appliance doors, smart eyewear and visors.

What are the main benefits provided by the technology (any quantitative data would be welcome in addition to a qualitative description)?

There are many benefits. What we are developing is a film-based technology suitable for window integration and retrofitting. It will have short switching times (<1 min as compared to 10-15 min for state-of-the-art EC windows), and most importantly cost-effective, high-throughput production will be possible (roll-to-roll manufacturing).

Our technology will also have a higher bleached state visual light transmittance as compared to state-of-the-art EC windows (60-65 % vs. 50-55 %); a lower darkened state visual light transmittance as compared to state-of-the-art EC windows (5-10 % vs. 10-15 %); it will be fully colourless ("neutral tint") bleached state with no residual colour or hue.; it will have an appreciable g-value modulation as opposed to liquid crystal-based smart window film technologies; it is mechanically rugged; and it has a large thermal operation range (-25 to +60 °C).

Once the project is completed, what will be the next steps? How do you see the technology evolving in the future?

We will then have to focus on industrial development – scaling from pilot to production scale. Huge markets will become accessible in the future if the price target can be met and minimum performance requirements are fulfilled.