From 4df903ec9e2f46392370aa53b4b7ec6f0b456481 Mon Sep 17 00:00:00 2001
From: Bryn Pickering <17178478+brynpickering@users.noreply.github.com>
Date: Tue, 20 Aug 2024 11:20:28 +0100
Subject: [PATCH] Remove array copy (#666)

---
 src/calliope/backend/backend_model.py | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/src/calliope/backend/backend_model.py b/src/calliope/backend/backend_model.py
index 536938f8..ab0cd78f 100644
--- a/src/calliope/backend/backend_model.py
+++ b/src/calliope/backend/backend_model.py
@@ -1071,13 +1071,14 @@ def _get_variable_bound(
                 name,
                 f"Applying bound according to the {bound} parameter values.",
             )
-            bound_array = self.get_parameter(bound).copy()
+            bound_array = self.get_parameter(bound)
             fill_na = bound_array.attrs.get("default", fill_na)
             references.add(bound)
         else:
             bound_array = xr.DataArray(bound)
-        bound_array.attrs = {}
-        return bound_array.fillna(fill_na)
+        filled_bound_array = bound_array.fillna(fill_na)
+        filled_bound_array.attrs = {}
+        return filled_bound_array
 
     @contextmanager
     def _datetime_as_string(self, data: xr.DataArray | xr.Dataset) -> Iterator: