"Let There Be Light" is a science fiction short story by American writer Robert A. Heinlein, originally published in Super Science Stories magazine in May 1940 under the pseudonym Lyle Monroe.
This story draws on Heinlein's early leftist ideas, and makes references to George Bernard Shaw's The Apple Cart.
In the course of their discovery, the inventors also discover that these panels can also be used to derive power from light.
In attempting to bring their discovery to market, they encounter the active opposition of the Power Syndicate, a conglomeration of energy-producing companies dedicated to preserving their monopoly on power production.
"Douglas-Martin sunpower screens" appear in several other Heinlein stories, such as "The Roads Must Roll".