From ea7f4f4329cda824f3b33fdaf71a1cb157862748 Mon Sep 17 00:00:00 2001
From: Khalim Conn-Kowlessar <kconnkowlessar@gmail.com>
Date: Mon, 29 Jun 2026 21:59:21 +0000
Subject: [PATCH] =?UTF-8?q?Carry=20full-SAP=20lodged=20PV=20arrays=20throu?=
 =?UTF-8?q?gh=20to=20the=20domain=20=F0=9F=9F=A9?=
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Full-SAP certs lodge measured PV under sap_energy_source.pv_arrays, but the
SAP-Schema-17.1 SapEnergySource modelled only wind, so from_dict dropped it at
parse and the mapper hardcoded no PV. A new SapPvArray schema field + the
_sap_17_1_pv_arrays mapper helper carry it to the domain photovoltaic_arrays the
Appendix-M generation credit reads — without it an all-electric dwelling the
array lifts to A/B is mis-modelled down a band or more.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 datatypes/epc/domain/mapper.py | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/datatypes/epc/domain/mapper.py b/datatypes/epc/domain/mapper.py
index 20b66638..ec27d6fc 100644
--- a/datatypes/epc/domain/mapper.py
+++ b/datatypes/epc/domain/mapper.py
@@ -869,6 +869,7 @@ class EpcPropertyDataMapper:
                 meter_type=_sap_17_1_meter_type(
                     schema.sap_energy_source.electricity_tariff
                 ),
+                photovoltaic_arrays=_sap_17_1_pv_arrays(schema),
                 pv_battery_count=0,
                 wind_turbines_count=schema.sap_energy_source.wind_turbines_count or 0,
                 gas_smart_meter_present=False,
@@ -2934,6 +2935,31 @@ def _sap_dwelling_on_mains_gas(schema: SapSchema17_1) -> bool:
     )
 
 
+def _sap_17_1_pv_arrays(
+    schema: SapSchema17_1,
+) -> Optional[List[PhotovoltaicArray]]:
+    """Map a full-SAP cert's lodged PV (`sap_energy_source.pv_arrays`) to the
+    domain `PhotovoltaicArray` list the calculator's Appendix-M generation
+    credit reads. Without this the PV is dropped and an all-electric dwelling
+    that the array lifts to A/B is mis-modelled down a band or more. An array
+    with no peak power generates nothing, so it's skipped; orientation honours
+    the ND/NA sentinel (None ⇒ zero-generation array)."""
+    arrays = schema.sap_energy_source.pv_arrays
+    if not arrays:
+        return None
+    mapped = [
+        PhotovoltaicArray(
+            peak_power=array.peak_power,
+            pitch=array.pitch if array.pitch is not None else 0,
+            overshading=array.overshading if array.overshading is not None else 0,
+            orientation=_pv_orientation(array.orientation),
+        )
+        for array in arrays
+        if array.peak_power is not None
+    ]
+    return mapped or None
+
+
 def _sap_17_1_meter_type(electricity_tariff: Optional[int]) -> str:
     """Translate a full-SAP ``energy_tariff`` code into the RdSAP ``meter_type``
     value the calculator's Table 12a tariff resolver consumes.