Method for increasing the yield produced by a solar collector over a prescribed observation period (T 1 to T N), wherein the solar collector has a collector surface impinged upon by sunlight, which is inclined relative to the horizontal by a first elevation angle (α) and rotated relative to the north-south direction (N, S) by an azimuth angle (β), and wherein a reflector inclined relative to the horizontal by a second elevation angle (γ) is arranged opposite the collector surface and reflects a portion, dependent on the position of the sun, of the sunlight incident on the reflector onto the collector surface, the second elevation angle (γ) being fixed, characterized in that the second elevation angle (γ) is selected in dependence on the geographical installation location of the solar collector and the size of the first elevation angle (α) and the azimuth angle (β) in such a way that the sum of the products, summed in successive observation intervals over a prescribed observation period (T 1) to (T N), of the portion of the sunlight reflected onto the collector surface per observation interval (ΔT) and a yield value assigned to the solar collector is at a maximum, wherein the yield value is the measured or simulated mean value of the local yields in the respective observation interval at the geographical location of the solar collector in at least two previous years, and wherein the size of the second elevation angle (γ) is determined by the following method steps: a) prescribing a value (L R) for the length of the reflector, b) prescribing a time-of-year initial value (T 1) and end value (T N) and also the observation intervals (ΔT) for the observation period, c) prescribing an initial value (γ 1) and end value (γ N) for the second elevation angle (γ) and the intervals for the changing of the second elevation angle (Δγ), d) prescribing a time-of-day initial value (t 1) and end value (t N) for a sub-observation time period and the sub-observation intervals (Δt), e) prescribing the average yield (E T1) to (E TN) for the respectively assigned observation interval (T 1) to (T N), f) forming the yield values (E Vγ1,T1) to (E Vγ1, TN) by adding up the average portion of the sunlight reflected by the reflector onto the solar collector for the second elevation angle (γ 1) in a respective observation interval (T 1) in dependence on the position of the sun in the observation time period (t 1) to (t N) and multiplying the value obtained by an average yield (E T1) assigned to this observation interval (T 1) for the solar collector in successive observation intervals (ΔT) in the observation time period (T 1) to (T N), g) forming the mean value of the values (E Vγ1,T1) to (E Vγ1,TN) determined under f) to form a total value (E VM,γ1), assigned to the initial value (γ 1), for the yield in the prescribed observation time period (T 1) to (T N), h) varying the value for the second elevation angle (γ) within the initial and end values (γ 1) to (γ N) by a prescribed amount (Δγ) and determining the total value (E VM,γi), assigned to this angle value (γ i), for the yield in the prescribed observation time period (T 1) to (T N) by repeating steps e) to g), i) determining the greatest total value (E VM,γmax) for the yield in the prescribed observation time period (T 1) to (T N) from the values (E VM,γ1) to (E VM,γN) determined in method steps g) and h) and the angle value (γ max) assigned to this total value. a) prescribing a value (L R) for the length of the reflector, b) prescribing a time-of-year initial value (T 1) and end value (T N) and also the observation intervals (ΔT) for the observation period, c) prescribing an initial value (γ 1) and end value (γ N) for the second elevation angle (γ) and the intervals for the changing of the second elevation angle (Δγ), d) prescribing a time-of-day initial value (t 1) and end value (t N) for a sub-observation time period and the sub-observation intervals (Δt), e) prescribing the average yield (E T1) to (E TN) for the respectively assigned observation interval (T 1) to (T N), f) forming the yield values (E Vγ1,T1) to (E Vγ1, TN) by adding up the average portion of the sunlight reflected by the reflector onto the solar collector for the second elevation angle (γ 1) in a respective observation interval (T 1) in dependence on the position of the sun in the observation time period (t 1) to (t N) and multiplying the value obtained by an average yield (E T1) assigned to this observation interval (T 1) for the solar collector in successive observation intervals (ΔT) in the observation time period (T 1) to (T N), g) forming the mean value of the values (E Vγ1,T1) to (E Vγ1,TN) determined under f) to form a total value (E VM,γ1), assigned to the initial value (γ 1), for the yield in the prescribed observation time period (T 1) to (T N), h) varying the value for the second elevation angle (γ) within the initial and end values (γ 1) to (γ N) by a prescribed amount (Δγ) and determining the total value (E VM,γi), assigned to this angle value (γ i), for the yield in the prescribed observation time period (T 1) to (T N) by repeating steps e) to g), i) determining the greatest total value (E VM,γmax) for the yield in the prescribed observation time period (T 1) to (T N) from the values (E VM,γ1) to (E VM,γN) determined in method steps g) and h) and the angle value (γ max) assigned to this total value.