In the image d. above, the unit was able to produce at high levels for only the first cycle of clear to opaque. The unit quickly falls from 1 mA to 50% by the 3rd shift. NREL notes this, obviously, need be fixed.
The paper, in the section titled ‘Mechanism of switchable device degradation’, breaks down the observations of the chemical issues leading to the degradation. Existing smart windows work for 50,000 cycles. A standard solar panel is expected to be above 80% efficiency for 9,125 full day cycles (25 years).
The ‘champion’ prototype peaked at 11.3% efficiency – while the average of the five units was 10.3%.
Recently, a group released an analysis suggesting that 40% of US electricity could be supplied via the windows of structures. Their model projected that the 5 to 7 million square feet of glass would need be about 5% efficiency in order to hit those numbers.