diff --git a/doc/release_notes.rst b/doc/release_notes.rst
index 988b8803d..ae003d072 100644
--- a/doc/release_notes.rst
+++ b/doc/release_notes.rst
@@ -10,6 +10,8 @@ Release Notes
 Upcoming Release
 ================
 
+* Set p_nom = p_nom_min for generators with baseyear == grouping_year in add_existing_baseyear. This has no effect on the optimization but helps n.statistics to correctly report already installed capacities.
+
 * Reverted outdated hotfix for doubled renewable capacity in myopic optimization.
 
 * Added Enhanced Geothermal Systems for generation of electricity and district heat.
diff --git a/scripts/add_existing_baseyear.py b/scripts/add_existing_baseyear.py
index 4e6f5ddaa..a209e934d 100644
--- a/scripts/add_existing_baseyear.py
+++ b/scripts/add_existing_baseyear.py
@@ -272,9 +272,9 @@ def add_power_capacities_installed_before_baseyear(n, grouping_years, costs, bas
 
             # this is for the year 2020
             if not already_build.empty:
-                n.generators.loc[already_build, "p_nom_min"] = capacity.loc[
-                    already_build.str.replace(name_suffix, "")
-                ].values
+                n.generators.loc[already_build, "p_nom"] = n.generators.loc[
+                    already_build, "p_nom_min"
+                ] = capacity.loc[already_build.str.replace(name_suffix, "")].values
             new_capacity = capacity.loc[new_build.str.replace(name_suffix, "")]
 
             if "m" in snakemake.wildcards.clusters: