Add tests for effective irradiance behavior in noct_sam

Author: Chirag3841

tests/test_noct_sam_eff_irradiance.py

@@ -0,0 +1,51 @@
+import numpy as np
+from pvlib.temperature import noct_sam
+
+def test_noct_sam_effective_irr_reduces_temp():
+    # Effective irradiance should lower predicted module temp
+    t_full = noct_sam(
+        poa_global=800, temp_air=20, wind_speed=2,
+        noct=45, module_efficiency=0.20
+    )
+
+    t_eff_600 = noct_sam(
+        poa_global=800, temp_air=20, wind_speed=2,
+        noct=45, module_efficiency=0.20,
+        effective_irradiance=600
+    )
+
+    t_eff_200 = noct_sam(
+        poa_global=800, temp_air=20, wind_speed=2,
+        noct=45, module_efficiency=0.20,
+        effective_irradiance=200
+    )
+
+    assert t_eff_600 < t_full
+    assert t_eff_200 < t_eff_600
+
+
+def test_noct_sam_oc_case_reduces_temp():
+    # Open-circuit (efficiency=0) should still respond to effective irradiance
+    t_oc_full = noct_sam(
+        poa_global=800, temp_air=20, wind_speed=2,
+        noct=45, module_efficiency=0.0
+    )
+
+    t_oc_eff = noct_sam(
+        poa_global=800, temp_air=20, wind_speed=2,
+        noct=45, module_efficiency=0.0,
+        effective_irradiance=300
+    )
+
+    assert t_oc_eff < t_oc_full
+
+
+def test_noct_sam_not_below_ambient_for_small_eff():
+    # Very small effective irradiance should not predict cooling below ambient
+    t_small = noct_sam(
+        poa_global=800, temp_air=20, wind_speed=2,
+        noct=45, module_efficiency=0.20,
+        effective_irradiance=1.0
+    )
+
+    assert t_small >= 20.0 - 1e-6  # small numerical tolerance