diff --git a/homeassistant/components/watttime/sensor.py b/homeassistant/components/watttime/sensor.py
index f44249ecde1..4453044e0d2 100644
--- a/homeassistant/components/watttime/sensor.py
+++ b/homeassistant/components/watttime/sensor.py
@@ -17,8 +17,9 @@ from homeassistant.const import (
     MASS_POUNDS,
     PERCENTAGE,
 )
-from homeassistant.core import HomeAssistant, callback
+from homeassistant.core import HomeAssistant
 from homeassistant.helpers.entity_platform import AddEntitiesCallback
+from homeassistant.helpers.typing import StateType
 from homeassistant.helpers.update_coordinator import (
     CoordinatorEntity,
     DataUpdateCoordinator,
@@ -115,20 +116,7 @@ class RealtimeEmissionsSensor(CoordinatorEntity, SensorEntity):
         self._attr_unique_id = f"{coordinator.config_entry.entry_id}_{description.key}"
         self.entity_description = description
 
-    @callback
-    def _handle_coordinator_update(self) -> None:
-        """Respond to a DataUpdateCoordinator update."""
-        self.update_from_latest_data()
-        self.async_write_ha_state()
-
-    async def async_added_to_hass(self) -> None:
-        """Handle entity which will be added."""
-        await super().async_added_to_hass()
-        self.update_from_latest_data()
-
-    @callback
-    def update_from_latest_data(self) -> None:
-        """Update the state."""
-        self._attr_native_value = self.coordinator.data[
-            self.entity_description.data_key
-        ]
+    @property
+    def native_value(self) -> StateType:
+        """Return the value reported by the sensor."""
+        return self.coordinator.data[self.entity_description.data_key]