diff --git a/README b/README
index fa7f379..c1280fb 100644
--- a/README
+++ b/README
@@ -1,3 +1,17 @@
+This is the docker container and script to publish the energy consumption of the Huette to the MQTT broker. 
+
+The data is a json array with index 0 means today, index 1 one day in the past, index 2 two days in the past and so on. The data is in watt hours.
+
+e.g. [1000, 2000, 3000, 4000, 5000, 6000, 7000, 8000]
+
+# Environment variables
+
+MQTT_HOST: The host of the MQTT broker
+MQTT_PORT: (Optional) The port of the MQTT broker
+MQTT_TOPIC: The topic to publish to
+MQTT_USERNAME: (Optional) The user for the MQTT broker
+MQTT_PASSWORD: (Optional) The password for the MQTT broker
+
 # Build
 
 ```
diff --git a/main.py b/main.py
index a61c1e7..e8e2fcb 100644
--- a/main.py
+++ b/main.py
@@ -44,7 +44,17 @@ def main():
     port = int(os.getenv("MQTT_PORT", 1883))
     topic = os.getenv("MQTT_TOPIC")
 
+    username = os.getenv("MQTT_USERNAME")
+    password = os.getenv("MQTT_PASSWORD")
+
     mqttc = mqtt.Client(mqtt_enums.CallbackAPIVersion.VERSION2)
+
+    if username:
+        if not password:
+            raise ValueError("MQTT_USERNAME is set but MQTT_PASSWORD is not set")
+
+        mqttc.username_pw_set(username, password)
+
     mqttc.connect(host, port)
     mqttc.loop_start()