diff --git a/linerate/models/cigre207.py b/linerate/models/cigre207.py
index 4fe5407..ce0e212 100644
--- a/linerate/models/cigre207.py
+++ b/linerate/models/cigre207.py
@@ -14,11 +14,13 @@
 
 class Cigre207(ThermalModel):
     def __init__(
-        self, span: Span, weather: Weather, time: Date, include_diffuse_radiation: bool = True
+        self, span: Span, weather: Weather, time: Date, include_diffuse_radiation: bool = True,
+            direct_radiation_factor: float = 1.0
     ):
         super().__init__(span, weather)
         self.time = time
         self.include_diffuse_radiation = include_diffuse_radiation
+        self.direct_radiation_factor = direct_radiation_factor
 
     @_copy_method_docstring(ThermalModel)
     def compute_joule_heating(
@@ -49,7 +51,8 @@ def compute_solar_heating(
         )
         sin_eta = switch_cos_sin(cos_eta)
 
-        I_B = cigre207.solar_heating.compute_direct_solar_radiation(sin_H_s, y)
+        I_B = (self.direct_radiation_factor
+               * cigre207.solar_heating.compute_direct_solar_radiation(sin_H_s, y))
         if self.include_diffuse_radiation:
             I_d = cigre207.solar_heating.compute_diffuse_sky_radiation(I_B, sin_H_s)
             F = self.span.ground_albedo