OpenEVT ☀️ Envertec EVT800 Client ⚡

Take control of your solar energy monitoring with OpenEVT!

OpenEVT is tool that empowers you to directly communicate with your Envertec solar microinverter, giving you complete ownership of your solar performance data - without being restricted to the Envertec APIs. OpenEVT connects directly to your microinverter on your LAN and can be used to integrate and monitor your inverter in Home Assistant or Prometheus.

• Improved Stability: Continue monitoring your PV performance even during an Envertec Cloud outage.
• Data Privacy: Be in charge of your data. Monitor your PV performance within your own private network.
• Integration Ready: Integrate PV monitoring into Home Assistant, Grafana and other monitoring tools and home automation systems.
• Improved Resolution: Poll your PV system more often with lower latency for better resolution in your monitoring tools.

OpenEVT is known to work with the following Envertec inverters:

• EVT800B

Install

To install OpenEVT (Go 1.21+):

$ go install https://github.com/brandon1024/OpenEVT/cmd/openevt@latest

Usage

To connect to your microinverter, you need:

• the LAN address and port number (e.g. 192.0.2.1:14889),
• the inverter serial number (e.g. 31583078)

Before connecting to your inverter, you must set up the inverter following the instructions provided by the manufacturer. The inverter must be connected to your LAN and must be configured in TCP-Server mode in the Network Parameter Settings.

The inverter enters a low-power standby mode when there's no sunlight, so OpenEVT won't be able to connect during the night.

$ openevt --addr 192.168.2.54:14889 --serial-number 31583078

To read inverter status:

$ curl localhost:9090/inverter

Or configure Prometheus scrape target:

global:
  scrape_interval: 15s
scrape_configs:
  - job_name: openevt
    metrics_path: '/metrics'
    static_configs:
      - targets: ['localhost:9090']

To configure Home Assistant to read from OpenEVT, add the following to your configuration.yaml:

# Envertech Inverter Configuration
rest:
  - scan_interval: 15
    resource: "http://openevt:9090/inverter"
    method: "GET"
    sensor:
      - name: "Envertech Inverter [EVT-1] DC Voltage"
        value_template: "{{ value_json.Module1.InputVoltageDC | round(2) }}"
        unit_of_measurement: V
        device_class: voltage
      - name: "Envertech Inverter [EVT-1] AC Voltage"
        value_template: "{{ value_json.Module1.OutputVoltageAC | round(2) }}"
        unit_of_measurement: V
        device_class: voltage
      - name: "Envertech Inverter [EVT-1] Power"
        value_template: "{{ value_json.Module1.OutputPowerAC | round(2) }}"
        unit_of_measurement: W
        device_class: power
      - name: "Envertech Inverter [EVT-1] Frequency"
        value_template: "{{ value_json.Module1.OutputFrequencyAC | round(2) }}"
        unit_of_measurement: Hz
        device_class: frequency
      - name: "Envertech Inverter [EVT-1] Energy (Total)"
        value_template: "{{ value_json.Module1.TotalEnergy | round(2) }}"
        unit_of_measurement: kWh
        device_class: energy
        state_class: total
      - name: "Envertech Inverter [EVT-1] Temperature"
        value_template: "{{ value_json.Module1.Temperature | round(2) }}"
        unit_of_measurement: ℃
        device_class: temperature
  - scan_interval: 15
    resource: "http://openevt-prod:9090/inverter"
    method: "GET"
    sensor:
      - name: "Envertech Inverter [EVT-2] DC Voltage"
        value_template: "{{ value_json.Module2.InputVoltageDC | round(2) }}"
        unit_of_measurement: V
        device_class: voltage
      - name: "Envertech Inverter [EVT-2] AC Voltage"
        value_template: "{{ value_json.Module2.OutputVoltageAC | round(2) }}"
        unit_of_measurement: V
        device_class: voltage
      - name: "Envertech Inverter [EVT-2] Power"
        value_template: "{{ value_json.Module2.OutputPowerAC | round(2) }}"
        unit_of_measurement: W
        device_class: power
      - name: "Envertech Inverter [EVT-2] Frequency"
        value_template: "{{ value_json.Module2.OutputFrequencyAC | round(2) }}"
        unit_of_measurement: Hz
        device_class: frequency
      - name: "Envertech Inverter [EVT-2] Energy (Total)"
        value_template: "{{ value_json.Module2.TotalEnergy | round(2) }}"
        unit_of_measurement: kWh
        device_class: energy
        state_class: total
      - name: "Envertech Inverter [EVT-2] Temperature"
        value_template: "{{ value_json.Module2.Temperature | round(2) }}"
        unit_of_measurement: ℃
        device_class: temperature

To show usage information, use the --help flag:

$ openevt --help
  -addr string
        address and port of the microinverter (e.g. 192.0.2.1:14889)
  -poll-interval duration
        attempt to poll the inverter status more frequently than advertised
  -reconnect-interval duration
        interval between connection attempts (e.g. 1m) (default 1m0s)
  -serial-number string
        serial number of your microinverter (e.g. 31583078)
  -web.disable-exporter-metrics
        exclude metrics about the exporter itself (go_*)
  -web.listen-address string
        address on which to expose metrics (default ":9090")
  -web.telemetry-path string
        path under which to expose metrics (default "/metrics")

Finding your Inverter on the LAN

To find the address and port of your inverter, connect to the wireless access point of your inverter. The SSID is the serial number of your inverter, like 31583078. Once connected, login using your credentials.

Under the System tab, the LAN IP address can be found in the STA Mode IP Address field.

Under the Other Settings tab, you can find the port number in the Port ID field.

Alternatively, you can scan your network with a tool like nmap:

nmap -p 14889 192.168.2.0/24

Building

To build OpenEVT (Go 1.21+):

make

Contributing

Help us support more inverter models! If your inverter also supports a local mode connection, send us your packet captures to help us expand support for more inverters.

If OpenEVT doesn't work for your particular inverter model, please create an issue and we'll do our best to support you.

Technical Info

OpenEVT was developed by reverse engineering the communication between the EnverView app and the microinverter's local mode port. There's a lot we don't understand yet, but here's what we've found so far.

Poll Message Format

When we first connect to the inverter, we issue a poll message to the inverter to request it's current state. The microinverter will immediately respond with an inverter state message. The message is 32 bytes long and has the following format:

RAW:    3638 3030 3130 3638 3130 3737 3332 3332 3332 3332 3030 3030 3030 3030 3966 3136
ASCII:   68   00   10   68   10   77   32   32   32   32   00   00   00   00   9f   16
        |----------------------|      |-----------------| |-----------------|      |--|
                 FIXED                |   INVERTER SN   | |     PADDING     |      DONE

This message looks quite similar to the acknowledge message, the key differences being the 77 and 9f words.

Inverter State Message Format

Periodically, the inverter will push a message to the client that contains performance metrics of both inverter modules. The message is 86 bytes long and has the following format:

RAW: 6800 5668 1051 3232 3232 7001 7900 0000 0000 0000 3232 3232 7079 2f47 00e6 0003 49dc 22b3 3a7e 31f8 0200 0000 0000 0000 0000 0000 3232 3233 7079 302b 00e4 0002 c7f6 2319 3a7e 31f8 0200 0000 0000 0000 0000 0000 9b16
                    |-------| |-------| |------------| |-------| |--| |--| |--| |-------| |--| |--| |--| |---------------------------| |-------| |--| |--| |--| |-------| |--| |--| |--| |---------------------------|   ||
                      EVTID      FW?                      MID     FW   #1   #2     #3      #4   #5   #6                                   MID     FW   #1   #2     #3      #4   #5   #6

Metrics for the first module are decoded as follows:

• #1: [26,27] DC Input Voltage: 23.64V (* 64 / 32768)
• #2: [28,29] AC Output Power: 3.59W (* 512 / 32768)
• #3: [30-33] Total Energy: 26.31kWh (* 4 / 32768)
• #4: [34,35] Temperature: 29.40C (* (256 / 32768) - 40)
• #5: [36,37] AC Output Voltage: 233.97V (* 512 / 32768)
• #6: [38,39] AC Output Frequency: 49.97Hz (* 128 / 32768)

Metrics for the second module are decoded as follows:

• #1: [58,59] DC Input Voltage: 24.08V (* 64 / 32768)
• #2: [60,61] AC Output Power: 3.56W (* 512 / 32768)
• #3: [62-65] Total Energy: 22.25kWh (* 4 / 32768)
• #4: [66,67] Temperature: 30.20C (* (256 / 32768) - 40)
• #5: [68,69] AC Output Voltage: 233.97V (* 512 / 32768)
• #6: [70,71] AC Output Frequency: 49.97Hz (* 128 / 32768)

Acknowledge Message Format

Once we receive an inverter state message from the inverter, we need to acknowledge it with an acknowledge message. The message format is quite similar to the poll message (the 50 and 78 words are relevant):

HEX:    3638 3030 3130 3638 3130 3530 3332 3332 3332 3332 3030 3030 3030 3030 3738 3136
ASCII:   68   00   10   68   10   50   32   32   32   32   00   00   00   00   78   16
        |----------------------|      |-----------------| |-----------------|      |--|
                                      |   INVERTER SN   | |     PADDING     |

It was found that the client needs to acknowledge messages otherwise the inverter hangs up the connection and disconnects the client.

Acknowledgements and Mentions

A special thanks to Manuelimnetz for offering hints on how to decode messages.

For a Node-Red implementation leveraging UDP mode of the inverter, see the implementation from @alarbiere.

License

MIT License. Copyright (c) 2022 Brandon Richardson.