diff --git a/scripts/add_electricity.py b/scripts/add_electricity.py
index 7cea165b..68d2d5fa 100755
--- a/scripts/add_electricity.py
+++ b/scripts/add_electricity.py
@@ -426,6 +426,13 @@ def attach_conventional_generators(
     add_missing_carriers(n, carriers)
     add_co2_emissions(n, costs, carriers)
 
+    # Replace carrier "natural gas" with the respective technology (OCGT or
+    # CCGT) to align with PyPSA names of "carriers" and avoid filtering "natural
+    # gas" powerplants in ppl.query("carrier in @carriers")
+    ppl.loc[ppl["carrier"] == "natural gas", "carrier"] = ppl.loc[
+        ppl["carrier"] == "natural gas", "technology"
+    ]
+
     ppl = (
         ppl.query("carrier in @carriers")
         .join(costs, on="carrier", rsuffix="_r")
diff --git a/scripts/add_existing_baseyear.py b/scripts/add_existing_baseyear.py
index 062e21aa..b2c534e6 100644
--- a/scripts/add_existing_baseyear.py
+++ b/scripts/add_existing_baseyear.py
@@ -129,10 +129,14 @@ def add_power_capacities_installed_before_baseyear(n, grouping_years, costs, bas
         "Oil": "oil",
         "OCGT": "OCGT",
         "CCGT": "CCGT",
-        "Natural Gas": "gas",
         "Bioenergy": "urban central solid biomass CHP",
     }
 
+    # Replace Fueltype "Natural Gas" with the respective technology (OCGT or CCGT)
+    df_agg.loc[df_agg["Fueltype"] == "Natural Gas", "Fueltype"] = df_agg.loc[
+        df_agg["Fueltype"] == "Natural Gas", "Technology"
+    ]
+
     fueltype_to_drop = [
         "Hydro",
         "Wind",
@@ -601,12 +605,13 @@ if __name__ == "__main__":
 
         snakemake = mock_snakemake(
             "add_existing_baseyear",
+            configfiles="config/test/config.myopic.yaml",
             simpl="",
-            clusters="45",
-            ll="v1.0",
+            clusters="5",
+            ll="v1.5",
             opts="",
-            sector_opts="8760H-T-H-B-I-A-solar+p3-dist1",
-            planning_horizons=2020,
+            sector_opts="24H-T-H-B-I-A-solar+p3-dist1",
+            planning_horizons=2030,
         )
 
     logging.basicConfig(level=snakemake.config["logging"]["level"])
diff --git a/scripts/build_powerplants.py b/scripts/build_powerplants.py
index f25f111b..cbe94505 100755
--- a/scripts/build_powerplants.py
+++ b/scripts/build_powerplants.py
@@ -98,13 +98,15 @@ def add_custom_powerplants(ppl, custom_powerplants, custom_ppl_query=False):
 
 
 def replace_natural_gas_technology(df):
-    mapping = {"Steam Turbine": "OCGT", "Combustion Engine": "OCGT"}
-    tech = df.Technology.replace(mapping).fillna("OCGT")
-    return df.Technology.where(df.Fueltype != "Natural Gas", tech)
+    mapping = {"Steam Turbine": "CCGT", "Combustion Engine": "OCGT"}
+    tech = df.Technology.replace(mapping).fillna("CCGT")
+    return df.Technology.mask(df.Fueltype == "Natural Gas", tech)
 
 
 def replace_natural_gas_fueltype(df):
-    return df.Fueltype.where(df.Fueltype != "Natural Gas", df.Technology)
+    return df.Fueltype.mask(
+        (df.Technology == "OCGT") | (df.Technology == "CCGT"), "Natural Gas"
+    )
 
 
 if __name__ == "__main__":