diff --git a/homeassistant/components/opower/coordinator.py b/homeassistant/components/opower/coordinator.py
index f6f3524d630..6957ae4984c 100644
--- a/homeassistant/components/opower/coordinator.py
+++ b/homeassistant/components/opower/coordinator.py
@@ -5,18 +5,16 @@ import logging
 from types import MappingProxyType
 from typing import Any, cast
 
-import aiohttp
 from opower import (
     Account,
     AggregateType,
-    CannotConnect,
     CostRead,
     Forecast,
-    InvalidAuth,
     MeterType,
     Opower,
     ReadResolution,
 )
+from opower.exceptions import ApiException, CannotConnect, InvalidAuth
 
 from homeassistant.components.recorder import get_instance
 from homeassistant.components.recorder.models import StatisticData, StatisticMetaData
@@ -89,7 +87,7 @@ class OpowerCoordinator(DataUpdateCoordinator[dict[str, Forecast]]):
             raise UpdateFailed(f"Error during login: {err}") from err
         try:
             forecasts: list[Forecast] = await self.api.async_get_forecast()
-        except aiohttp.ClientError as err:
+        except ApiException as err:
             _LOGGER.error("Error getting forecasts: %s", err)
             raise
         _LOGGER.debug("Updating sensor data with: %s", forecasts)
@@ -102,7 +100,7 @@ class OpowerCoordinator(DataUpdateCoordinator[dict[str, Forecast]]):
         """Insert Opower statistics."""
         try:
             accounts = await self.api.async_get_accounts()
-        except aiohttp.ClientError as err:
+        except ApiException as err:
             _LOGGER.error("Error getting accounts: %s", err)
             raise
         for account in accounts:
@@ -271,7 +269,7 @@ class OpowerCoordinator(DataUpdateCoordinator[dict[str, Forecast]]):
             cost_reads = await self.api.async_get_cost_reads(
                 account, AggregateType.BILL, start, end
             )
-        except aiohttp.ClientError as err:
+        except ApiException as err:
             _LOGGER.error("Error getting monthly cost reads: %s", err)
             raise
         _LOGGER.debug("Got %s monthly cost reads", len(cost_reads))
@@ -290,7 +288,7 @@ class OpowerCoordinator(DataUpdateCoordinator[dict[str, Forecast]]):
             daily_cost_reads = await self.api.async_get_cost_reads(
                 account, AggregateType.DAY, start, end
             )
-        except aiohttp.ClientError as err:
+        except ApiException as err:
             _LOGGER.error("Error getting daily cost reads: %s", err)
             raise
         _LOGGER.debug("Got %s daily cost reads", len(daily_cost_reads))
@@ -308,7 +306,7 @@ class OpowerCoordinator(DataUpdateCoordinator[dict[str, Forecast]]):
             hourly_cost_reads = await self.api.async_get_cost_reads(
                 account, AggregateType.HOUR, start, end
             )
-        except aiohttp.ClientError as err:
+        except ApiException as err:
             _LOGGER.error("Error getting hourly cost reads: %s", err)
             raise
         _LOGGER.debug("Got %s hourly cost reads", len(hourly_cost_reads))
diff --git a/homeassistant/components/opower/manifest.json b/homeassistant/components/opower/manifest.json
index 7227f7171ac..d168cba5752 100644
--- a/homeassistant/components/opower/manifest.json
+++ b/homeassistant/components/opower/manifest.json
@@ -7,5 +7,5 @@
   "documentation": "https://www.home-assistant.io/integrations/opower",
   "iot_class": "cloud_polling",
   "loggers": ["opower"],
-  "requirements": ["opower==0.8.8"]
+  "requirements": ["opower==0.8.9"]
 }
diff --git a/homeassistant/components/opower/sensor.py b/homeassistant/components/opower/sensor.py
index 7f8eb22d1e6..f9d0fe62332 100644
--- a/homeassistant/components/opower/sensor.py
+++ b/homeassistant/components/opower/sensor.py
@@ -97,7 +97,7 @@ ELEC_SENSORS: tuple[OpowerEntityDescription, ...] = (
         device_class=SensorDeviceClass.DATE,
         entity_category=EntityCategory.DIAGNOSTIC,
         entity_registry_enabled_default=False,
-        value_fn=lambda data: data.start_date,
+        value_fn=lambda data: str(data.start_date),
     ),
     OpowerEntityDescription(
         key="elec_end_date",
@@ -105,7 +105,7 @@ ELEC_SENSORS: tuple[OpowerEntityDescription, ...] = (
         device_class=SensorDeviceClass.DATE,
         entity_category=EntityCategory.DIAGNOSTIC,
         entity_registry_enabled_default=False,
-        value_fn=lambda data: data.end_date,
+        value_fn=lambda data: str(data.end_date),
     ),
 )
 GAS_SENSORS: tuple[OpowerEntityDescription, ...] = (
@@ -169,7 +169,7 @@ GAS_SENSORS: tuple[OpowerEntityDescription, ...] = (
         device_class=SensorDeviceClass.DATE,
         entity_category=EntityCategory.DIAGNOSTIC,
         entity_registry_enabled_default=False,
-        value_fn=lambda data: data.start_date,
+        value_fn=lambda data: str(data.start_date),
     ),
     OpowerEntityDescription(
         key="gas_end_date",
@@ -177,7 +177,7 @@ GAS_SENSORS: tuple[OpowerEntityDescription, ...] = (
         device_class=SensorDeviceClass.DATE,
         entity_category=EntityCategory.DIAGNOSTIC,
         entity_registry_enabled_default=False,
-        value_fn=lambda data: data.end_date,
+        value_fn=lambda data: str(data.end_date),
     ),
 )
 
diff --git a/requirements_all.txt b/requirements_all.txt
index 84a2cd7ad2e..2d1d4b1cca9 100644
--- a/requirements_all.txt
+++ b/requirements_all.txt
@@ -1592,7 +1592,7 @@ openwrt-luci-rpc==1.1.17
 openwrt-ubus-rpc==0.0.2
 
 # homeassistant.components.opower
-opower==0.8.8
+opower==0.8.9
 
 # homeassistant.components.oralb
 oralb-ble==0.17.6
diff --git a/requirements_test_all.txt b/requirements_test_all.txt
index 326670c9f63..d699ae56a97 100644
--- a/requirements_test_all.txt
+++ b/requirements_test_all.txt
@@ -1328,7 +1328,7 @@ openhomedevice==2.2.0
 openwebifpy==4.3.1
 
 # homeassistant.components.opower
-opower==0.8.8
+opower==0.8.9
 
 # homeassistant.components.oralb
 oralb-ble==0.17.6