Interesting! If I understand this correctly the panels used the thermoelectric effect [1],[2].
60W per panel of that size (see [1], PDF p.5, subtitle of image) would of course be rather low for today's standards.
I guess one could build something like the mentioned panels with lots of peltier elements but I'd imagine that it would be quite a bit more expensive per generated power nowadays (otherwise someone would probably already do this). (As far as I know the thermoelectric effect is mostly used in RTGs for producing electricity.)
60W per panel of that size (see [1], PDF p.5, subtitle of image) would of course be rather low for today's standards.
I guess one could build something like the mentioned panels with lots of peltier elements but I'd imagine that it would be quite a bit more expensive per generated power nowadays (otherwise someone would probably already do this). (As far as I know the thermoelectric effect is mostly used in RTGs for producing electricity.)
[1] https://www.worldradiohistory.com/Archive-Modern-Electrics/M..., PDF pages 5,6 & 34 (content pages 243, 244 & 272)
[2] https://upload.wikimedia.org/wikipedia/commons/b/bb/G._H._CO...