diff --git a/pvnet_app/app.py b/pvnet_app/app.py
index 4e6bd0a..8f4fe89 100644
--- a/pvnet_app/app.py
+++ b/pvnet_app/app.py
@@ -77,6 +77,12 @@
 model_name_ocf_db = "pvnet_v2"
 use_adjuster = os.getenv("USE_ADJUSTER", "True").lower() == "true"
 
+# If environmental variable is true, the sum-of-GSPs will be computed and saved under a different
+# model name. This can be useful to compare against the summation model and therefore monitor its
+# performance in production
+save_gsp_sum = os.getenv("SAVE_GSP_SUM", "False").lower() == "true"
+gsp_sum_model_name_ocf_db = "pvnet_gsp_sum"
+
 # ---------------------------------------------------------------------------
 # LOGGER
 formatter = logging.Formatter(
@@ -213,6 +219,8 @@ def app(
 
     logger.info(f"Using `pvnet` library version: {pvnet.__version__}")
     logger.info(f"Using {num_workers} workers")
+    logger.info(f"Using adjduster: {use_adjuster}")
+    logger.info(f"Saving GSP sum: {save_gsp_sum}")
 
     # Allow environment overwrite of model
     model_name = os.getenv("APP_MODEL", default=default_model_name)
@@ -491,6 +499,18 @@ def app(
         logger.info(
             f"National forecast is {da_abs.sel(gsp_id=0, output_label='forecast_mw').values}"
         )
+        
+    if save_gsp_sum:
+        # Compute the sum if we are logging the sume of GSPs independently
+        logger.info("Summing across GSPs to for independent sum-of-GSP saving")
+        da_abs_sum_gsps = (
+            da_abs.sum(dim="gsp_id")
+            # Only select the central forecast for the GSP sum. The sums of different p-levels 
+            # are not a meaningful qauntities
+            .sel(output_label=["forecast_mw"])
+            .expand_dims(dim="gsp_id", axis=0)
+            .assign_coords(gsp_id=[0])
+        )
 
     # ---------------------------------------------------------------------------
     # Escape clause for making predictions locally
@@ -514,6 +534,24 @@ def app(
             update_gsp=True,
             apply_adjuster=apply_adjuster,
         )
+        
+        if save_gsp_sum:
+            # Save the sum of GSPs independently - mainly for summation model monitoring
+            sql_forecasts = convert_dataarray_to_forecasts(
+                da_abs_sum_gsps, 
+                session, 
+                model_name=gsp_sum_model_name_ocf_db, 
+                version=pvnet_app.__version__
+            )
+
+            save_sql_forecasts(
+                forecasts=sql_forecasts,
+                session=session,
+                update_national=True,
+                update_gsp=False,
+                apply_adjuster=False,
+            )
+            
 
     logger.info("Finished forecast")
 
diff --git a/tests/test_app.py b/tests/test_app.py
index 931769d..dfc4c8b 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -1,4 +1,3 @@
-from pvnet_app.app import app
 import tempfile
 import zarr
 import os
@@ -36,21 +35,24 @@ def test_app(db_session, nwp_data, sat_data, gsp_yields_and_systems, me_latest):
         # Set model version
         os.environ["APP_MODEL_VERSION"] = "96ac8c67fa8663844ddcfa82aece51ef94f34453"
         os.environ["APP_SUMMATION_MODEL_VERSION"] = "4a145d74c725ffc72f482025d3418659a6869c94"
+        os.environ["SAVE_GSP_SUM"] = "True"
 
         # Run prediction
+        # This import needs to come after the environ vars have been set
+        from pvnet_app.app import app
         app(gsp_ids=list(range(1, 318)))
 
     # Check forecasts have been made
-    # (317 GSPs + 1 National) = 318 forecasts
+    # (317 GSPs + 1 National + GSP-sum) = 319 forecasts
     # Doubled for historic and forecast
     forecasts = db_session.query(ForecastSQL).all()
-    assert len(forecasts) == 318 * 2
+    assert len(forecasts) == 319 * 2
 
     # Check probabilistic added
     assert "90" in forecasts[0].forecast_values[0].properties
     assert "10" in forecasts[0].forecast_values[0].properties
 
     # 318 GSPs * 16 time steps in forecast
-    assert len(db_session.query(ForecastValueSQL).all()) == 318 * 16
-    assert len(db_session.query(ForecastValueLatestSQL).all()) == 318 * 16
-    assert len(db_session.query(ForecastValueSevenDaysSQL).all()) == 318 * 16
+    assert len(db_session.query(ForecastValueSQL).all()) == 319 * 16
+    assert len(db_session.query(ForecastValueLatestSQL).all()) == 319 * 16
+    assert len(db_session.query(ForecastValueSevenDaysSQL).all()) == 319 * 16