diff --git a/scripts/plot_validation_electricity_production.py b/scripts/plot_validation_electricity_production.py
index 5c5569d0..e95a8126 100644
--- a/scripts/plot_validation_electricity_production.py
+++ b/scripts/plot_validation_electricity_production.py
@@ -45,6 +45,12 @@ if __name__ == "__main__":
         header=[0, 1],
         parse_dates=True,
     )
+    subset_technologies = ["Geothermal", "Nuclear", "Biomass", "Lignite", "Oil", "Coal"]
+    lowercase_technologies = [
+        technology.lower() if technology in subset_technologies else technology
+        for technology in historic.columns.levels[1]
+    ]
+    historic.columns = historic.columns.set_levels(lowercase_technologies, level=1)
 
     colors = n.carriers.set_index("nice_name").color.where(
         lambda s: s != "", "lightgrey"