Solar Divert using the P1 port of Dutch and Belgian DSMR5 Smart Meter

[pdhoogh]

The DSMRv5 Smart Meter has a P1 port. You can stick a SmartGateways WiFi gateway in there: https://smartgateways.nl/en/product/smart-meter-wifi-gateway/ it is powered by the smart meter P1 port, reads out the smart meter and makes it available on MQTT / WiFi.

On the Synology NAS, a MQTT Broker is installed (Mosquito Docker) to which the SmartGateway thing connects and publishes all the data read out from the DSMRv5 smart meter. To date, no data element in there can be directly used for OpenEVSE, but it is almost there. A tiny transform is necessary: multiply by 1000 to have the reading in Watts as used by OpenEVSE rather than the kWatts read out from the smart meter.

On the Synology NAS, one can run a small Python program to do the transform and publish the result to "Power1", similar to what the OpenEnergyMonitor team is using.

In the OpenEVSE, connect to the MQTT broker and subscribe to the transformed item. Here called DS220PLUS/POWER1. Use it in Export mode as +I/-E.

I have used it for three years now and it worked very well. Recently, the code stopped working because of changes in Mosquito MQTT. Here is the fixed code, without any comments to keep this post short:

import paho.mqtt.client as mqtt

# Callback running on connection
def on_connect(client, userdata, flags, rc):
    print("Connected with result code "+str(rc))
    client.subscribe("dsmr/reading/power_delivered_netto")

def on_message(client, userdata, message):
    powerkW = float(message.payload.decode("utf-8"))
    power1 = powerkW * 1000
    client.publish("DS220PLUS/POWER1", str(power1), qos=0, retain=False)


# MQTT broker address
mqttBroker = "192.168.xxx.yy"

# Create an MQTT client instance
client = mqtt.Client(mqtt.CallbackAPIVersion.VERSION1,"DS220PLUS")
client.on_connect = on_connect
client.on_message = on_message  

# Connect to the broker (specify port and keepalive)
client.connect(mqttBroker, port=1883, keepalive=60)

client.loop_forever()