this is Giovanni from EI2030.org!
I have posted a concept mod for the Pi-Top [v3]: I was thinking more of a cyberdeck idea since the solar powered display would need a larger panel since it would use more power. Under the keyboard fits a 5" screen, although I plan to order a different one without HDMI since the one in the photo arrived doa.
The project is part of a low-power OS development: https://forum.ei2030.org/t/low-power-e-paper-os/138 Eventually with optimizations, an e-paper display may be able to use a larger display and the solar panel could use less than half of the 14" screen. Hope you like the pics!