It seems unlikely that the pyramids were power plants and obelisks energy receivers [1], but maybe power plants of the future will look like the pyramids and energy receivers like obelisks.
The pyramids seem to have been built in the 26th century BCE rather than 100th, but an advanced ur-civilization may have developed the means and will that "they actually got out with whisk brooms, scoop shovels and little spoons and cleared out every single trace of their daily lives, their utensils, their pottery, their wood, their tools and so on" [2].
1. https://medium.com/understanding-reality/were-the-pyramids-p...
2. https://www.pbs.org/wgbh/nova/pyramid/explore/howold2.html