A new solar power plant design that utilizes a “Light Room” built underground, commercially available mirrors used in CSP and CPV power plants, and also commercially available PV modules. The usage of a Light Room built underground significantly increases sunlight to electricity conversion efficiency by a higher percentage of sunlight directed towards the PV modules, which are kept cool and clean via fans. Construction, operations and maintenance become easier, faster and cheaper. Overall land usage requirement, investment cost per unit installed power and LCOE are significantly reduced. The design allows installation in rural and urban areas, making it possible for applications not feasible with the current state of the art.