Solar thermal power plant using indirect evaporation, comprising at least the following components: - a primary circuit having a heat transfer medium conduction system, comprising at least one solar thermal subassembly for heating the heat transfer medium by means of solar energy, - a steam secondary circuit having at least: - a preheating stage to preheat feedwater, - a steam generation stage downstream from the preheating stage to generate steam, - a steam superheating stage downstream from the steam generation stage to superheat the steam, - a steam turbine system (21, 22, 23) linked to an outlet of the steam superheating stage via a steam conduction system, which is fed when operational with the superheated steam, - a condensing system installed downstream from the steam turbine system (21, 22, 23) on the exhaust steam side to condense the steam, and - a water conduction system having a feedwater tank located between the condensing system and the preheating stage, and - a generator, which is coupled directly or indirectly to the steam turbine system (21, 22, 23), wherein the primary circuit comprises a heat exchanger group having a heat transfer medium conduction system to transfer the heat energy from the heat transfer medium of the primary circuit to the steam superheating stage, the steam generation stage and the preheating stage of the steam secondary circuit, characterised in that the heat transfer medium conduction system has at least one bypass conduction path (B1, B2, B3) around the steam superheating stage and/or the steam generation stage, which is fed back into the main mass flow of the heat transfer medium conduction system before the preheating stage. - a primary circuit having a heat transfer medium conduction system, comprising at least one solar thermal subassembly for heating the heat transfer medium by means of solar energy, - a steam secondary circuit having at least: - a preheating stage to preheat feedwater, - a steam generation stage downstream from the preheating stage to generate steam, - a steam superheating stage downstream from the steam generation stage to superheat the steam, - a steam turbine system (21, 22, 23) linked to an outlet of the steam superheating stage via a steam conduction system, which is fed when operational with the superheated steam, - a condensing system installed downstream from the steam turbine system (21, 22, 23) on the exhaust steam side to condense the steam, and - a water conduction system having a feedwater tank located between the condensing system and the preheating stage, and - a preheating stage to preheat feedwater, - a steam generation stage downstream from the preheating stage to generate steam, - a steam superheating stage downstream from the steam generation stage to superheat the steam, - a steam turbine system (21, 22, 23) linked to an outlet of the steam superheating stage via a steam conduction system, which is fed when operational with the superheated steam, - a condensing system installed downstream from the steam turbine system (21, 22, 23) on the exhaust steam side to condense the steam, and - a water conduction system having a feedwater tank located between the condensing system and the preheating stage, and - a generator, which is coupled directly or indirectly to the steam turbine system (21, 22, 23), wherein the primary circuit comprises a heat exchanger group having a heat transfer medium conduction system to transfer the heat energy from the heat transfer medium of the primary circuit to the steam superheating stage, the steam generation stage and the preheating stage of the steam secondary circuit, characterised in that the heat transfer medium conduction system has at least one bypass conduction path (B1, B2, B3) around the steam superheating stage and/or the steam generation stage, which is fed back into the main mass flow of the heat transfer medium conduction system before the preheating stage.