Charles W. Thurston, Contributing Writer
The illusive market for solar coatings took another step forward in February, when organic coatings maker SolarWindows announced collaboration with Corning
for applications utilizing the latter’s flexible Willow Glass. This
combination is promising in that the glass can be produced on
long rolls and processed – including lamination – at high pressure and temperature in the 500° C range, beyond the capability
of solar film.
The Willow Glass, as thin as 100 microns (μm), is said to be
capable of supporting thinner backplanes and color filters for
both Organic Light Emitting Diodes (OLED) and liquid crystal
displays (LCD). The glass also is said to be malleable enough
to produce 4000 square feet of glass on one spool; Corning
cites availability in widths up to 1.3 meters and lengths of up
to 300 meters.
One solar product already on the market utilizing 2 mm flex
glass is the 2.5 kilowatts-per-hour SmartFlower, from Austria, a
flower-shaped set of solar petals that follows the sun on a dou-ble-axis tracker. The residential or commercial product, with 18
square meters of thin film solar panels laminated to flex glass, is
available for about $10,000.
The most likely near-term application for the solar flex glass
or veneer, as the company prefers to label it, is in commercial
Building Integrated Photovoltaic (BIPV) retrofitting or new construction, with a payback of less than the expected 20 year warranty for the solar photovoltaic production. SolarWindows has
been working with the U.S. Department of Energy’s National
Renewable Energy Laboratory under a commercialization
agreement for some time.
“While generating electricity on flexible glass presents obvious commercial opportunities, this approach is especially
attractive to high-speed roll-to-roll manufacturing for maximizing output while lowering production costs,” said Dr.
Maikel van Hest, a senior scientist in the Thin Film Material
Science and Processing Group within the Material Science
Center at NREL.
The NREL agreement is a Cooperative Research and
Development Agreement (CRADA) under which SolarWindow
began work in March 2016 to jointly “enhance product per-
formance, increase scale, and improve reliability; and develop
new features and obtain important performance certifications
required for a commercial rollout,” NREL notes.
In addition, the team will focus on various SolarWindow
product-specific goals, including: “large scale window fabrica-
tion; interconnection development for easy ‘plug-n-play’ on-site
installation; advanced performance measurement and modeling
of SolarWindow when installed in various building types and
geographies; and Solar Window performance under varying ar-
tificial and natural light conditions,” NREL noted.
Other flexible solar glass applications include transporta-
tion, where smart glass applications could co-exist on solar glass
windshields and other glass surfaces. Similarly, flexible glass,
which weighs very little, can be incorporated into electronics
devices, clothing, and a variety of military mobile applications.
The value of the flexible solar glass market is difficult to
estimate, given the novelty of the technology, covered under a
host of patents. One market research house indicates that the
global flexible display market is expected to approximate $4
billion by 2020. Another research report suggests that some
$40 billion in value is added to the basic $20 billion-plus
global flat glass market by laminating, tempering, coating and
silvering processes. CW
Solar Coatings
Meet Flexible Glass
Willow Glass on a roll. Credit: Stemmerich
