Operating method for a plant in primary industry, - wherein a basic part of the plant is operated in accordance with a plant cycle, - wherein during the plant cycles hot exhaust gases are produced in a first phase of the respective plant cycle and in a second phase of the respective plant cycle either no hot exhaust gases are produced or the hot exhaust gases are produced only to a considerably reduced extent with respect to the first phase, - wherein the hot exhaust gases, to the respective extent to which they are produced, are discharged from the basic part of the plant via a system of pipelines, - wherein in an evaporator device (5, 7) installed in the system of pipelines, at least in the first phase, water is evaporated by means of the hot exhaust gases to form saturated steam and the saturated steam is fed to a steam storage device (9, 11), - wherein in the first phase -- the saturated steam stored in the steam storage device (9, 11) is passed through a superheater installed in the system of pipelines and is superheated there by means of the hot exhaust gases to form superheated steam, -- a first part of the superheated steam is passed in a charging direction through the buffer store by means of a first valve device arranged between the superheater and a buffer store, -- the first part of the superheated steam in the buffer store heats a storage medium located there, and -- a second part of the superheated steam, complementary to the first part, is passed by means of the first valve device to a steam turbine while bypassing the buffer store and characterised in that in the second phase - saturated steam is removed from the steam storage device (9, 11), at least partially passed through the superheater and combined by means of the first valve device with superheated steam which is removed from the buffer store counter to the charging direction, and - the combination of steam which has passed through the superheater and superheated steam removed from the buffer store is passed to the steam turbine. - wherein a basic part of the plant is operated in accordance with a plant cycle, - wherein during the plant cycles hot exhaust gases are produced in a first phase of the respective plant cycle and in a second phase of the respective plant cycle either no hot exhaust gases are produced or the hot exhaust gases are produced only to a considerably reduced extent with respect to the first phase, - wherein the hot exhaust gases, to the respective extent to which they are produced, are discharged from the basic part of the plant via a system of pipelines, - wherein in an evaporator device (5, 7) installed in the system of pipelines, at least in the first phase, water is evaporated by means of the hot exhaust gases to form saturated steam and the saturated steam is fed to a steam storage device (9, 11), - wherein in the first phase -- the saturated steam stored in the steam storage device (9, 11) is passed through a superheater installed in the system of pipelines and is superheated there by means of the hot exhaust gases to form superheated steam, -- a first part of the superheated steam is passed in a charging direction through the buffer store by means of a first valve device arranged between the superheater and a buffer store, -- the first part of the superheated steam in the buffer store heats a storage medium located there, and -- a second part of the superheated steam, complementary to the first part, is passed by means of the first valve device to a steam turbine while bypassing the buffer store and -- the saturated steam stored in the steam storage device (9, 11) is passed through a superheater installed in the system of pipelines and is superheated there by means of the hot exhaust gases to form superheated steam, -- a first part of the superheated steam is passed in a charging direction through the buffer store by means of a first valve device arranged between the superheater and a buffer store, -- the first part of the superheated steam in the buffer store heats a storage medium located there, and -- a second part of the superheated steam, complementary to the first part, is passed by means of the first valve device to a steam turbine while bypassing the buffer store and - saturated steam is removed from the steam storage device (9, 11), at least partially passed through the superheater and combined by means of the first valve device with superheated steam which is removed from the buffer store counter to the charging direction, and - the combination of steam which has passed through the superheater and superheated steam removed from the buffer store is passed to the steam turbine.