It had already happened even by 1922.<quoted text>
You might ought to read that book that he quoted from - all of it. It is apparent that he didn't. Nope. King Coal probably just went to Google Books and put in "coal" and "civilization" and then quoted what came up.'Cause line 1 of chapter 1 is a real shocker:
"Scientists tell us that the energy poured by the sun on the Desert of Sahara in a single day exceeds by fourfold the energy stored in the annual production of all the coal fields in the world. They dream of a time when the radiant energy of the sun will be captured and turned to the uses of man. Then the wheels of our myriad machines will spin with the sun and stars."
When that book was written 91 years ago, the day when solar technology would replace coal was thought to be a hundred years away. For someone living in 1922 it was more than a lifetime away, a time to dream about that the author knew neither he nor his immediate readers would live to see. For us living today, it is only 9 years away.
I have pictures of solar water heaters on the roofs of buildings in San Francisco, circa 1890. I don't know how well they worked, but dozens of houses had them.
In the Southern US, the sun was taken into account, with our wide shaded porches and shotgun houses. In the Mediterranean region, houses are massive and light colored, to both use and defeat the heat.
Even "dumb" animals know to use the sun in various ways, and how to avoid it if need be.
We all know this in our DNA. We have lived with the sun for billions of years, from our most primitive forms, to our "apex" of evolutionary development today.
Those SF heaters were the birth; we live now in the teenage years of active/passive solar, when it's growing wildly and weirdly, and trying to find it's place in the world while improving constantly.