README.rst

pyess

Python library for LG ESS Solar power converters with EnerVU app compatibility

Python library for communication with LG ESS power converter / energy storage devices for photovoltaic solar generators

This library is not endorsed by the manufacturer. It was written for lack of an official API. It should allow to design home automation around the current state of a solar energy system - e.g. turn appliances on when there is surplus solar power. LG only offers access via a badly scriptable web page or alternatively via a proprietary app that - at least on my phone - crashes at least twice for every successful startup.

Disclaimer: For this python module I reverse-engineered the communication between the LG EnerVu Plus 1.2.3 Android App and the Energy Storage / Inverter device, so there is some likelihood that it will work for devices that can be accessed via that app. Nevertheless it looks like some of the interface is delivered by the ESS as html via the network. Therefore it may be that not all commands work against all boxes. I only have customer-level access to my own box, so this module only offers those parts of the API that are accessible to me as a customer. As far as I can tell the installer has higher privileges and can fiddle with internal parameters of the system from what I saw him do when he installed the system.

Usage

Command Line

This module comes with a rudimentary command line interface that allows for the following actions.

Fetch the device password

Caveat: To fetch the device password you need to be connected to the devices wifi. Once you are on the wifi you can run the following to get the password. Write it down, it seems it is a static password per device:

esscli --action get_password

The command assumes that the ess device is listening on 192.168.23.1 on its own wifi, in my setup it reproducibly chooses that IP.

Find the esses on your network

Get a list of ESS devices on the local network (your home wifi, not the one of ess):

esscli --action list_ess

Fetch the state from ess as json

fetch a bunch of json states as json and display the result on the command line:

esscli --action get_data --password <your ess_password>

Examples for the data available: - current power from and to the grid and the battery - current voltage and power from both strings of the photovoltaic system independently - current ip address - details on grid power, battery state, daily and monthly statistics

Log ess state into a graphite server

This command will fetch the home and common info from ess every 10 seconds and log them against a graphite server (assuming standard port and udp as protocol). Running this command requires the ess password to be passed on the command line:

esscli --action log_against_graphite --password <your_ess_password> --graphite <ip_of_graphite_server>

MQTT wrapper

Sync ess state with an mqtt server (also accepts commands)

To connect your ESS with an mqtt server run the following in your venv:

essmqtt --mqtt_server=<your_mqtt_server> --mqtt_user <your_mqtt_username> --mqtt_password <your_mqtt_password> --ess_password <your_ess_password>

Your ESS will show up in ess/# on mqtt.

Available values to control the ess (write true/false) Remember that this is an MIT-Licensed software and I take no responsibility for the usage of this library. That being said I send the same commands the app would send to trigger these actions to my best knowledge.:

ess/control/winter_mode
ess/control/fastcharge
ess/control/active

Available paths with metrics to read from:

ess/home/statistics/pcs_pv_total_power 0
ess/home/statistics/batconv_power 190
ess/home/statistics/bat_use 1
ess/home/statistics/bat_status 2
ess/home/statistics/bat_user_soc 81.25
ess/home/statistics/load_power 191
ess/home/statistics/load_today 0.0
ess/home/statistics/grid_power 1
ess/home/statistics/current_day_self_consumption 0.0
ess/home/statistics/current_pv_generation_sum 0
ess/home/statistics/current_grid_feed_in_energy 0
ess/home/direction/is_direct_consuming_ 0
ess/home/direction/is_battery_charging_ 0
ess/home/direction/is_battery_discharging_ 1
ess/home/direction/is_grid_selling_ 0
ess/home/direction/is_grid_buying_ 1
ess/home/direction/is_charging_from_grid_ 0
ess/home/operation/status start
ess/home/operation/mode 1
ess/home/wintermode/winter_status on
ess/home/pcs_fault/pcs_status pcs_ok
ess/common/PV/brand LGE-SOLAR
ess/common/PV/capacity 5850
ess/common/PV/pv1_voltage 26.500000
ess/common/PV/pv2_voltage 26.700001
ess/common/PV/pv1_power 0
ess/common/PV/pv2_power 0
ess/common/PV/pv1_current 0.110000
ess/common/PV/pv2_current 0.000000
ess/common/PV/today_pv_generation_sum 0
ess/common/PV/today_month_pv_generation_sum 438389
ess/common/BATT/status 2
ess/common/BATT/soc 81.2
ess/common/BATT/dc_power 190
ess/common/BATT/winter_setting on
ess/common/BATT/winter_status on
ess/common/BATT/safty_soc 20
ess/common/BATT/today_batt_discharge_enery 135
ess/common/BATT/today_batt_charge_energy 0
ess/common/BATT/month_batt_charge_energy 72692
ess/common/BATT/month_batt_discharge_energy 51250
ess/common/GRID/active_power 2.790000
ess/common/GRID/a_phase 230.899994
ess/common/GRID/freq 49.959999
ess/common/GRID/today_grid_feed_in_energy 0
ess/common/GRID/today_grid_power_purchase_energy 0
ess/common/GRID/month_grid_feed_in_energy 266094
ess/common/GRID/month_grid_power_purchase_energy 7037
ess/common/LOAD/load_power 191
ess/common/LOAD/today_load_consumption_sum 135
ess/common/LOAD/today_pv_direct_consumption_enegy 0
ess/common/LOAD/today_batt_discharge_enery 135
ess/common/LOAD/today_grid_power_purchase_energy 0
ess/common/LOAD/month_load_consumption_sum 157890
ess/common/LOAD/month_pv_direct_consumption_energy 99603
ess/common/LOAD/month_batt_discharge_energy 51250
ess/common/LOAD/month_grid_power_purchase_energy 7037
ess/common/PCS/today_self_consumption 0.0
ess/common/PCS/month_co2_reduction_accum 311256
ess/common/PCS/today_pv_generation_sum 0
ess/common/PCS/month_pv_generation_sum 438389
ess/common/PCS/today_grid_feed_in_energy 0
ess/common/PCS/month_grid_feed_in_energy 266094
ess/common/PCS/pcs_stauts 3
ess/common/PCS/feed_in_limitation 70
ess/common/PCS/operation_mode 0

I use mosquitto_sub to find the values I'm interested in while debugging like so:

mosquitto_sub -v -h <your_mqtt_server> -p 1883 -u <your_mqtt_user> -P <your_mqtt_password> -t "#"

Configuring essmqtt with a config file

To permanently configure essmqtt you can create a config file in either /etc/essmqtt.conf or ~/essmqtt.conf of the user running essmqtt or you can specify which config file to load by using the argument --config_file. The config file can contain any of the command line arguments. Example:

ess_password = <your_ess_password>
mqtt_server = <your_mqtt_server>
mqtt_user = <your_mqtt_username>
mqtt_password = <your_mqtt_password>

essmqtt autoconfig for homeassistant

Essmqtt can provide autoconfiguration for [homeassistant](https://www.home-assistant.io/).

prerequisites: [mqtt must be set up with matt discovery in homeassistant](https://www.home-assistant.io/docs/mqtt/discovery/)

To select the sensors that should be autodiscovered by homeassistant, provide the --hass_autoconfig_sensors argument with a comma separated list of all mqtt pathes you want to see as sensors in homeassistant. Some autodetection of the value type is done so for instance if an mqtt path contains power it is assumed to be a power value in watts. Of course this can also be configured in a config file.

Example config file:

ess_password = <your_ess_password>
mqtt_server = <your_mqtt_server>
mqtt_user = <your_mqtt_username>
mqtt_password = <your_mqtt_password>
hass_autoconfig_sensors= ess/common/BATT/soc,ess/home/statistics/pcs_pv_total_power,ess/common/GRID/active_power,ess/common/LOAD/load_power

essmqtt as systemd service

To set up essmqtt as a daemon (systemd service) it is recommended to install it in a venv first:

python3.7 -m venv <path_to_venv>
<path_to_venv>/bin/pip install pyess

from then on essmqtt can be called via <path_to_venv>/bin/essmqtt.

A systemd service file /etc/systemd/system/essmqtt.service could look like so:

[Unit]
Description=ESS MQTT wrapper

[Service]
# all essmqtt command line arguments can be used here. it is recommended to configure essmqtt in a config file
# for this use case
ExecStart=<path_to_venv>/bin/essmqtt
# Restart will keep the service alive for instance in case the mqtt server goes down or isn't up yet
# when esmqqt starts
Restart=on-failure
# a sensible restart delay prevents fast restart loops potentially denial-of-servicing the ess.
RestartSec=10

[Install]
# we'd like to start, but only after network is up
WantedBy=default.target
Wants=network-online.target

It can be started like any regular service via systemctl start essmqtt or enabled for boot up starts via systemctl enable essmqtt. Logs can be displayed using systemctl as well via systemctl status essmqtt or for more lines systemctl status -n 100 essmqtt`

API

For the time being please use the docstrings in the code on https://github.com/gluap/pyess as documentation for the API. A good place to start is pyess/cli.py where you can find the implementation of the CLI. One thing available via the API but not yet via the CLI is the data for the daily / weekly / monthly / yearly statistics graphs that can be accessed via the EnerVu App.

Changelog

2020-06-01 0.1.10

• add another possible fix for #7 after logging showed that an MQTT error might be the cause.

2020-06-01 0.1.9

• add homeassistant auto config

2020-05-30 0.1.8

• refactor uploading to MQTT to avoid accidentally trying to access a string by key (should fix #8)

2020-05-30 0.1.7

• add config file to allow storing settings for essmqtt

2020-05-30 0.1.6

• repair crash introduced with 0.1.5

2020-05-30 0.1.5

• some extra logging, timeouts and exception handling. Might fix #7

2020-05-13 0.1.3

• add argument to increase polling time for "common" by a factor.

2020-05-05 0.1.3

• add argument to set ess hostname explicitly (avoiding mdns timeouts if necessary)

2020-04-29 0.1.2

• fix issue where esscli and essmqtt were incompatible with the app and confusing the web interface

2020-04-26 0.1.1

• fix issue where commands via mqtt were not working
• add --interval_seconds parameter for mqtt client to allow experimenting with poll timeouts on user side
• fix logout handling on aiohttp

2020-04-15 0.1.0

• fix issue with fetch_password using wrong IP
• fix documentation
• add new mqtt synchronization service script

2019-11-03 0.0.3

• add aiohttp-based backend for use with asyncio

2019-10-12 0.0.2

• some minor fixes

2019-10-09 0.0.1

• More documentation
• Initial commit for pypi relase

License:

Copyright (c) 2019 Paul Görgen

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.