diff --git a/nowcasting_dataset/data_sources/gsp/gsp_data_source.py b/nowcasting_dataset/data_sources/gsp/gsp_data_source.py
index 23495893..e7116101 100644
--- a/nowcasting_dataset/data_sources/gsp/gsp_data_source.py
+++ b/nowcasting_dataset/data_sources/gsp/gsp_data_source.py
@@ -550,6 +550,10 @@ def drop_gsp_by_threshold(
     if len(gsp_power) == 0:
         return gsp_power, meta_data
 
+    # There is an extra GSP in the new data, GSP ID 0 for the national forecast,
+    # which is not in the metadata, so dropping here
+    gsp_power = gsp_power.drop(columns=0)
+
     maximum_gsp = gsp_power.max()
 
     keep_index = maximum_gsp >= threshold_mw
diff --git a/tests/data/gsp/test.zarr/.zmetadata b/tests/data/gsp/test.zarr/.zmetadata
index 75d19b26..8ec61b21 100644
--- a/tests/data/gsp/test.zarr/.zmetadata
+++ b/tests/data/gsp/test.zarr/.zmetadata
@@ -6,7 +6,7 @@
         },
         "datetime_gmt/.zarray": {
             "chunks": [
-                25201
+                37657
             ],
             "compressor": {
                 "blocksize": 0,
@@ -29,7 +29,7 @@
                 "datetime_gmt"
             ],
             "calendar": "proleptic_gregorian",
-            "units": "minutes since 2016-01-01"
+            "units": "minutes since 2014-01-01"
         },
         "generation_mw/.zarray": {
             "chunks": [
@@ -70,7 +70,7 @@
                 "id": "blosc",
                 "shuffle": 1
             },
-            "dtype": "<U2",
+            "dtype": "<U21",
             "fill_value": null,
             "filters": null,
             "order": "C",
diff --git a/tests/data/gsp/test.zarr/datetime_gmt/.zarray b/tests/data/gsp/test.zarr/datetime_gmt/.zarray
index e7b20649..c5f38f43 100644
--- a/tests/data/gsp/test.zarr/datetime_gmt/.zarray
+++ b/tests/data/gsp/test.zarr/datetime_gmt/.zarray
@@ -1,6 +1,6 @@
 {
     "chunks": [
-        25201
+        37657
     ],
     "compressor": {
         "blocksize": 0,
diff --git a/tests/data/gsp/test.zarr/datetime_gmt/.zattrs b/tests/data/gsp/test.zarr/datetime_gmt/.zattrs
index 49c8d550..83ad40ac 100644
--- a/tests/data/gsp/test.zarr/datetime_gmt/.zattrs
+++ b/tests/data/gsp/test.zarr/datetime_gmt/.zattrs
@@ -3,5 +3,5 @@
         "datetime_gmt"
     ],
     "calendar": "proleptic_gregorian",
-    "units": "minutes since 2016-01-01"
+    "units": "minutes since 2014-01-01"
 }
diff --git a/tests/data/gsp/test.zarr/datetime_gmt/0 b/tests/data/gsp/test.zarr/datetime_gmt/0
index 376709e1..1a5a3fd8 100644
Binary files a/tests/data/gsp/test.zarr/datetime_gmt/0 and b/tests/data/gsp/test.zarr/datetime_gmt/0 differ
diff --git a/tests/data/gsp/test.zarr/generation_mw/0.0 b/tests/data/gsp/test.zarr/generation_mw/0.0
index 3f005ca7..93acda52 100644
Binary files a/tests/data/gsp/test.zarr/generation_mw/0.0 and b/tests/data/gsp/test.zarr/generation_mw/0.0 differ
diff --git a/tests/data/gsp/test.zarr/gsp_id/.zarray b/tests/data/gsp/test.zarr/gsp_id/.zarray
index 7917cc83..495cef80 100644
--- a/tests/data/gsp/test.zarr/gsp_id/.zarray
+++ b/tests/data/gsp/test.zarr/gsp_id/.zarray
@@ -9,7 +9,7 @@
         "id": "blosc",
         "shuffle": 1
     },
-    "dtype": "<U2",
+    "dtype": "<U21",
     "fill_value": null,
     "filters": null,
     "order": "C",
diff --git a/tests/data/gsp/test.zarr/gsp_id/0 b/tests/data/gsp/test.zarr/gsp_id/0
index 042a70a9..a11f948b 100644
Binary files a/tests/data/gsp/test.zarr/gsp_id/0 and b/tests/data/gsp/test.zarr/gsp_id/0 differ
diff --git a/tests/data/gsp/test.zarr/installedcapacity_mwp/0.0 b/tests/data/gsp/test.zarr/installedcapacity_mwp/0.0
index 8785d2f9..3a046fe6 100644
Binary files a/tests/data/gsp/test.zarr/installedcapacity_mwp/0.0 and b/tests/data/gsp/test.zarr/installedcapacity_mwp/0.0 differ