From f67668eb417d1f4077498afb792bc681020b2f99 Mon Sep 17 00:00:00 2001
From: Khalim Conn-Kowlessar <kconnkowlessar@gmail.com>
Date: Mon, 7 Oct 2024 12:43:40 +0100
Subject: [PATCH] tweaking google solar api ranking algorithm

---
 backend/apis/GoogleSolarApi.py | 20 +++++++-------------
 backend/app/assumptions.py     |  3 +++
 2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/backend/apis/GoogleSolarApi.py b/backend/apis/GoogleSolarApi.py
index 606b6970..f6e1b96d 100644
--- a/backend/apis/GoogleSolarApi.py
+++ b/backend/apis/GoogleSolarApi.py
@@ -69,7 +69,7 @@ class GoogleSolarApi:
         self.floor_area = None
         self.roof_area = None
         self.roof_segment_indexes = None
-        self.panel_area = None
+        self.panel_area = assumptions.RDSAP_AREA_PER_PANEL
         self.panel_wattage = None
         self.panel_performance = None
 
@@ -166,10 +166,6 @@ class GoogleSolarApi:
 
         self.roof_area = self.insights_data["solarPotential"]["wholeRoofStats"]['areaMeters2']
         self.floor_area = self.insights_data["solarPotential"]["wholeRoofStats"]['groundAreaMeters2']
-        self.panel_area = (
-            self.insights_data["solarPotential"]["panelHeightMeters"] *
-            self.insights_data["solarPotential"]["panelWidthMeters"]
-        )
         self.panel_wattage = self.insights_data["solarPotential"]["panelCapacityWatts"]
         if self.panel_wattage != 400:
             # In the API documentation, it claims that the default output is 250W, however we've only seen 400W, so if
@@ -450,8 +446,8 @@ class GoogleSolarApi:
 
         # We want max roi, minimal generation deficit, and max generation value - we create a ranking score
         # Assign equal weights to each metric
-        weights = {'roi': 0.6, 'generation_value': 0.2, 'generation_deficit': 0.2}
-        metrics = panel_performance[['roi', 'generation_value', 'generation_deficit']]
+        weights = {'roi': 0.8, 'generation_value': 0.2}
+        metrics = panel_performance[['roi', 'generation_value']].copy()
 
         # Normalize the columns (0 to 1 scale)
         scaler = MinMaxScaler()
@@ -459,12 +455,11 @@ class GoogleSolarApi:
 
         # Convert normalized metrics back to a dataframe
         normalized_metrics_df = pd.DataFrame(
-            normalized_metrics, columns=['roi', 'generation_value', 'generation_deficit']
+            normalized_metrics, columns=['roi', 'generation_value']
         )
         normalized_metrics_df['combined_score'] = (
             normalized_metrics_df['roi'] * weights['roi'] +
-            normalized_metrics_df['generation_value'] * weights['generation_value'] +
-            (1 - normalized_metrics_df['generation_deficit']) * weights['generation_deficit']
+            normalized_metrics_df['generation_value'] * weights['generation_value']
         )
 
         panel_performance['combined_score'] = normalized_metrics_df['combined_score'].values
@@ -799,7 +794,6 @@ class GoogleSolarApi:
                     "panel_performance": solar_api_client.panel_performance,
                     "unit_share_of_energy": 1
                 },
-                roof_area=solar_api_client.roof_area
             )
 
         return input_properties
@@ -825,7 +819,7 @@ class GoogleSolarApi:
                         n_panels=10, has_battery=False, n_floors=property_instance.number_of_floors
                     )["total"],
                     'weighted_ratio': None,
-                    'panneled_roof_area': 10 * 1.8,
+                    'panneled_roof_area': 10 * assumptions.RDSAP_AREA_PER_PANEL,
                     'array_wattage': 4000,
                     'initial_ac_kwh_per_year': 4000 * 0.95,  # Assumed 95% efficient wattage -> ac
                     'lifetime_ac_kwh': None,
@@ -845,7 +839,7 @@ class GoogleSolarApi:
                         n_panels=6, has_battery=False, n_floors=property_instance.number_of_floors
                     )["total"],
                     'weighted_ratio': None,
-                    'panneled_roof_area': 6 * 1.8,
+                    'panneled_roof_area': 6 * assumptions.RDSAP_AREA_PER_PANEL,
                     'array_wattage': 2400,
                     'initial_ac_kwh_per_year': 2400 * 0.95,  # Assumed 95% efficient wattage -> ac
                     'lifetime_ac_kwh': None,
diff --git a/backend/app/assumptions.py b/backend/app/assumptions.py
index 80baa69f..371b226d 100644
--- a/backend/app/assumptions.py
+++ b/backend/app/assumptions.py
@@ -7,6 +7,9 @@ AVERAGE_ASHP_EFFICIENCY = 250
 # be exported
 SOLAR_CONSUMPTION_PROPORTION = 0.5
 
+# Typically, each solar panel takes up around 3.4 m2 of roof space under RdSAP. This was been verified in Elmhurst
+RDSAP_AREA_PER_PANEL = 3.4
+
 DESCRIPTIONS_TO_FUEL_TYPES = {
     "Air source heat pump, radiators, electric": {
         "fuel": "Electricity", "cop": AVERAGE_ASHP_EFFICIENCY / 100