HBM's Nuclear Tech Wiki:Heliothermal Power Plant

A generator that uses reflector panels to concentrate sunlight on a boiler heating and generating steam that is used for power generation. Generating a small amount of energy more still very useful at the beginning of the game.

Make your generator as in the image below, very simples.

To place the panels facing the boiler use the Mirror Adjustemet Tool by clicking on the boiler and the panels.