Solar powered vacuum tubes

 an interesting juxtaposition of modern technology and a 1904 technology that is still in use today.

You might have your history a tad wrong.

It all began with Edmond Becquerel, a young physicist working in France, who in 1839 observed and discovered the photovoltaic effect— a process that produces a voltage or electric current when exposed to light or radiant energy. 

OP is talking about the inventor of the thermionic valve, John Ambrose Fleming.

OP is talking about the inventor of the thermionic valve, John Ambrose Fleming

Yes that, and his "modern" solar panel power.