Augustin Mouchot's Solar Concentrator (1878)
One of the, and perharps the, earliest solarpunk was the French inventor, Augustin Mouchot.
I had a chance to visit the Musée des Arts et Métiers de Paris yesterday, which among others expositions traces the evolution of machines that have enabled our society to tap into all sorts of energy sources. There is a heavy focus on steam, petrol, and nuclear engines but among those, Mouchot's solar concentrator replica stands out beautifully.
1/3 Replica at Musée des Arts et Métiers de Paris.
Close-up view of the darken copper collector, covered by transparent glass.
There was little information about the concentrator in the exhibit itself, but I have found much more interesting stuff in the documentation center (in French).
Collected technical and historical information available in the documentation center (in French).
I did not have much time to read everything available, next time I will reserve an entire day for the matter. Yet, skimming through, I have learned a few bits of trivia and read correspondance with the Academy of Science, the latter seemed to serve the purpose of today's scientific publications for disseminating ideas and experiment results.
Contrary to inventors of coal-powered steam engines and later petroleum internal combustion engines, which powered the industrial revolution and therefore made their inventors (and investors) quite wealthy, the solar inventions of Mouchot remained novelties with limited adoption in France. Mouchot worked on them in his spare time, beside a teaching career. He was motivated by a desire to improve the living conditions for all. He patented his invention in 1861 (no 48622) but quickly abandoned the patent after a positive reception of his first public displays, to avoid having the patents being the object of speculation . He was already anticipating by then the end of coal and other fossil fuels.
He died poor, a lesson that any sufficiently radical innovator should keep in mind, yet we still remember him today and who knows what impact his inventions have yet to have. Maybe he was simply 150 years too early and the fossil fuels will have had to fully run their course before we will truly learn to base on society on the Sun and other renewable energies.
 A. Mouchot "La Chaleur Solaire et ses Applications Industrielles." 1869 pdf