NOVELTY - The system (10) has a main fluid circuit (102) including a set of solar boiler panels for generating power from solar energy, and an auxiliary fluid circuit (110) in fluid communication with the main fluid circuit by a set of valves (120, 136, 138, 140). An auxiliary boiler (112) is connected to the auxiliary fluid circuit, and the valves are opened and closed to selectively place the auxiliary boiler in fluid communication with portions of the main fluid circuit to supply heat to the portions of the main fluid circuit in preparation to produce power from solar energy.    USE - Startup system for a solar boiler.    ADVANTAGE - The system reduces start up time, allows earlier completion of start up on a daily basis, and preserves the fatigue and creep/fatigue life of the solar boiler components. The system preserves the temperature to a controlled point during overnight layover of solar boilers, or during shut down. The system is easy to manufacture and use, and allows improved startup and shut down of the solar boiler.    DETAILED DESCRIPTION - The auxiliary boiler is selected from a group consisting of a liquid fuel fired type auxiliary boiler, a coal fired type auxiliary boiler, a biomass fired type auxiliary boiler, a natural gas fired type auxiliary boiler, a nuclear type auxiliary boiler, a geothermal type auxiliary boiler, and an electric type auxiliary boiler. The solar boiler panels include a set of steam generator panels, a set of superheater panels, and a set of reheater panels. INDEPENDENT CLAIMS are also included for the following:    (1) a method for starting up a solar boiler    (2) a method for shutting down a solar boiler to enable subsequent rapid startup.    DESCRIPTION OF DRAWING(S) - The drawing shows a circuit diagram of a startup system illustrating main and auxiliary fluid circuits of a solar boiler in a no-flow state when shut down during a night time layover.    Startup system (10)    Main fluid circuit (102)    Auxiliary fluid circuit (110)    Auxiliary boiler (112)    Valves (120, 136, 138, 140)    Condenser (126)