It is possible to radiate heat a clear night sky very effectively, because it is about 3K. Thus, systems built in areas where clouds are less common (e.g., deserts) usually have a very good heat sink at night. Thermal storage could store solar heat in the day and loose heat at night (storing cold).
A single cylinder(i.e., engine-alternator) Sterling engine-alternator might reliable enough to compete with solar PV--especially if the displacer is moved magnetically; thus, eliminating the crankshaft, seals, bearings, etc.