Engineering360: "Windows as transparent solar-thermoelectric systems"

"A prototype system was demonstrated to produce an output voltage of 4 V within an area of 0.01 m² exposed to sunshine."

4 volts open circuit but how much power?

0.4 mW / cm² max (figure 4b below, 40mW for 10cm x 10cm)

Transparent Power‐Generating Windows Based on Solar‐Thermal‐Electric Conversion - Zhang - 2021 - Advanced Energy Materials - Wiley Online Library

Ah but like all Windows systems will it crash when you need it most?

Windows will always be poor solar panels. Transmitting light and absorbing light to convert to electricity are conflicting requirements. In this case, converting light (UV and IR) to heat and then back to electricity adds the loss factor of Carnot efficiency as well as the losses inherent in thermoelectric conversion, electrical resistance and thermal conductance.