A Stirling engine design which is solar powered is disclosed. A solar receiver converts solar radiation to thermal energy, which is stored in a storage chamber. The engine includes a displacer chamber with a displacer piston which divides the chamber into hot and cold subchambers, the hot subchamber being heated by the storage chamber. A mechanism is provided for cooling the cold subchamber. The engine also includes an alternator chamber with an alternator piston which divides the chamber into working and bounce subchambers, the working subchamber being in fluid communication with the cold subchamber of the displacer. The working fluid circulates through the cold subchamber and the working subchamber and obtains heat from the storage chamber. The working fluid is displaced by the displacer piston to drive the alternator piston, and work output is obtained from the alternator piston.