diff --git a/core/edge_mining/adapters/domain/forecast/providers/home_assistant_api.py b/core/edge_mining/adapters/domain/forecast/providers/home_assistant_api.py
index fdcedf2..87d5a1c 100644
--- a/core/edge_mining/adapters/domain/forecast/providers/home_assistant_api.py
+++ b/core/edge_mining/adapters/domain/forecast/providers/home_assistant_api.py
@@ -66,8 +66,7 @@ def create(
         forecast_provider_config: ForecastProviderHomeAssistantConfig = config
         service_home_assistant_api = cast(ServiceHomeAssistantAPI, external_service)
 
-        # Use the builder to configure the provider, in this way we can
-        # ensure that all required entities are set.
+        # Use the builder to configure only the entities supplied by the user.
         builder = HomeAssistantForecastProviderBuilder(home_assistant=service_home_assistant_api, logger=logger)
 
         # Configure the builder with the entities and units
@@ -205,10 +204,20 @@ def set_remaining_today_energy_entity(
 
     def build(self) -> "HomeAssistantForecastProvider":
         """Builds the HomeAssistantForecastProvider instance."""
-        if not self.entity_forecast_power_actual_h:
-            raise ValueError("Entity ID for actual solar power forecast is required.")
-        if not self.entity_forecast_energy_actual_h:
-            raise ValueError("Entity ID for actual solar energy forecast is required.")
+        if not any(
+            (
+                self.entity_forecast_power_actual_h,
+                self.entity_forecast_power_next_1h,
+                self.entity_forecast_power_next_12h,
+                self.entity_forecast_power_next_24h,
+                self.entity_forecast_energy_actual_h,
+                self.entity_forecast_energy_next_1h,
+                self.entity_forecast_energy_today,
+                self.entity_forecast_energy_tomorrow,
+                self.entity_forecast_energy_remaining_today,
+            )
+        ):
+            raise ForecastError("At least one Home Assistant forecast entity is required.")
 
         forecast_provider = HomeAssistantForecastProvider(
             home_assistant=self.home_assistant,
diff --git a/core/tests/unit/adapters/domain/forecast/test_home_assistant_api.py b/core/tests/unit/adapters/domain/forecast/test_home_assistant_api.py
new file mode 100644
index 0000000..361c9c6
--- /dev/null
+++ b/core/tests/unit/adapters/domain/forecast/test_home_assistant_api.py
@@ -0,0 +1,48 @@
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from edge_mining.adapters.domain.forecast.providers.home_assistant_api import (
+    HomeAssistantForecastProviderFactory,
+)
+from edge_mining.domain.forecast.exceptions import ForecastError
+from edge_mining.shared.adapter_configs.forecast import ForecastProviderHomeAssistantConfig
+from edge_mining.shared.external_services.common import ExternalServiceAdapter
+
+
+@pytest.mark.asyncio
+async def test_factory_accepts_partial_entity_configuration():
+    home_assistant = MagicMock()
+    home_assistant.external_service_type = ExternalServiceAdapter.HOME_ASSISTANT_API
+    home_assistant.get_entity_state = AsyncMock(return_value=("1.5", {}))
+    home_assistant.parse_energy.return_value = 1.5
+    config = ForecastProviderHomeAssistantConfig(
+        entity_forecast_energy_today="sensor.solar_forecast_today",
+    )
+
+    provider = HomeAssistantForecastProviderFactory().create(
+        config=config,
+        logger=None,
+        external_service=home_assistant,
+    )
+
+    assert provider.entity_forecast_energy_today == "sensor.solar_forecast_today"
+    assert provider.entity_forecast_power_actual_h is None
+    assert provider.entity_forecast_energy_actual_h is None
+
+    forecast = await provider.get_forecast()
+
+    assert len(forecast.intervals) == 1
+    home_assistant.get_entity_state.assert_awaited_once_with("sensor.solar_forecast_today")
+
+
+def test_factory_rejects_empty_entity_configuration():
+    home_assistant = MagicMock()
+    home_assistant.external_service_type = ExternalServiceAdapter.HOME_ASSISTANT_API
+
+    with pytest.raises(ForecastError, match="At least one Home Assistant forecast entity is required"):
+        HomeAssistantForecastProviderFactory().create(
+            config=ForecastProviderHomeAssistantConfig(),
+            logger=None,
+            external_service=home_assistant,
+        )