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.)

[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...

Not sure about others but I personally am not a big fan of generalising that much: I'd prefer it if people would ideally say that it was for example the "most power efficient general purpose CPU/SoC" or at least something in that regard, not just "the best".

For example, have a look at https://openbenchmarking.org/vs/Processor/AMD%20Ryzen%20Thre... (user benchmarks of M1 and Threadripper). Compiling Linux on the 2990WX appears to be about 4 times faster than on the M2. (There are lots of other examples of one of the two CPUs being faster than the other but compiling Linux is the most time-expensive task I regularly do on my 2990WX. The energy usage in this task on the 2990WX is almost certainly a lot higher of course; this will be true for most tasks. However, the 2990WX is also 4 years older of course, manufactured in a different node, not very optimized for power saving and not operated in a very power saving mode.)