Tesla Solar Charger
Home Assistant Blueprint to charge Tesla car using surplus solar electricity and weather forecast.
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Disclaimer:
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Even though this automation has been created with care, the author cannot be responsible for any damage caused by this automation. Use at your own risk.
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Installation
- Set up "Grid Power Net" sensor in Home Assistant (HA) config, eg.
/config/configuration.yaml
template:
# For Enphase, grid_power_net is an integer in watts. Positive value means importing power from grid. Negative value means exporting power to grid.
- sensor:
name: Grid Power Net
state_class: measurement
icon: mdi:transmission-tower
unit_of_measurement: W
device_class: power
state: >
{{ states('sensor.envoy_[YourEnvoyId]_current_power_consumption')|int - states('sensor.envoy_[YourEnvoyId]_current_power_production')|int }}-
Copy the Blueprint file to, \HOMEASSISTANT\config\blueprints\automation\flashg\Tesla_solar_charger_automation.yaml
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Restart HA.
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Create 2 helper booleans, eg. Settings > Devices & Services > Helpers > Create Helper > Toggle
- Telsa Model3 charge from grid
- Tesla Model3 stop charging
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Config the Blueprint automation specifying charger voltage, maximum current and helper booleans created above, ie. Settings > Automations & Scenes > Blueprints > Tesla solar charger automation
My setup
- Home Assistant, https://www.home-assistant.io/
- Enphase Envoy Integration configured for 30 seconds update interval, https://github.com/briancmpbll/home_assistant_custom_envoy
- Tesla Custom Integration v3.20.4, https://github.com/alandtse/tesla
- Tesla UMC charger, 230V, max 15A.
- Tesla Model 3.
Features
- Charge from excess solar adjusting Tesla car charging current according to feedback loop value "Grid Power Net". The "Grid Power Net" sensor expresses negative power in Watts when exporting to grid, and positive power when consuming from grid.
- Support multi-day solar charging using sunrise trigger to start and sunset trigger to stop.
- Compatible with off-peak night time charging.
- Configurable daily car charge limit for 7 days. Default is to use the Tesla app charge limit.
- Automatically adjust to the highest charge limit set within a rainy forecast period. The highest charge limit is selected from the 7 days charge limit settings that are within the forecast period taking into account the charge limit on bad weather setting. The objective is to charge more before a rainy period. Default disabled.
- Might be possible to prolong car battery life by setting daily charge limit to 70%, and only charge more before a rainy period by enabling option to adjust daily car charge limit based on weather.
How to use
- Set your charging limit in app or car.
- Connect charger to car. Normal charging at constant current should begin immediately if schedule charging is disabled. After a little while, the script will take over and manage the charging current during daylight hours. Please see work-arounds below if automation cannot be triggered.
- There are 2 options on how to charge the car (see below).
- The script will stop if charger is turned off manually or automatically by car when reaching charge limit.
- To abort charging, turn on "Tesla Model3 stop charging". The script will take about a minute to terminate if using default values.
2 options on how to charge the car:
Option 1
To charge from excess solar, just plug in the charger. The initial charge current is 6A. After about 1 minute it will adjust the current according to amount of excess power exported to grid.
Option 2
To charge from grid, set your desired charging current and turn on "Telsa Model3 charge from grid".
Notes
Automation cannot be triggered
The Tesla triggers and conditions are slow to update unless car is polled often. Polling too often can drain the car battery. So might have to wait a minute or two for the conditions to refresh and the triggers to work. Please see below for possible work-arounds.
Work-arounds:
- Run the automation manually by selecting the automation and then select "Run Actions".
- Turn polling off, then on.
- Press the "Force data update" button before and after plugging in the charger.
Daily car charge limit settings
- If charge limit for day is not set, ie. set to -1, charge limit will be set according to the Tesla app.
- If charge limit for day is set and charge car based on weather is disabled, charge limit will be set according to the limit configured for the day. If necessary, user can manually override the charge limit setting within 30 seconds after it has been set by this automation.
- If charge limit for day is set and charge car based on weather is enabled, charge limit will be adjusted to the highest limit set within the rainy forecast period taking into account the car charge limit on bad weather setting. If necessary, user can manually override the charge limit setting within 30 seconds after it has been set by this automation.
- If charge car based on weather is enabled, charge limit and weather provider settings must be configured.
GUI display examples
Dashboard Tesla power card
https://github.com/reptilex/tesla-style-solar-power-card
type: custom:tesla-style-solar-power-card
name: Power Usage
show_w_not_kw: 1
# 3 flows between bubbles
grid_to_house_entity: sensor.grid_power_import
generation_to_grid_entity: sensor.grid_power_export
generation_to_house_entity: sensor.solar_power_consumption
# optional appliances with consumption and extra values
appliance1_consumption_entity: sensor.charger_power
appliance1_extra_entity: sensor.battery
# optional 3 main bubble icons for clickable entities
grid_entity: sensor.grid_power_net
house_entity: sensor.envoy_[YourEnvoyId]_current_power_consumption
generation_entity: sensor.solar_power_production
Dashboard Tesla solar charger control
type: entities
entities:
- entity: automation.[YourTeslaName]_solar_charger_automation
- type: attribute
entity: automation.[YourTeslaName]_solar_charger_automation
attribute: current
name: Running instance count
- type: attribute
entity: automation.[YourTeslaName]_solar_charger_automation
attribute: last_triggered
name: Last triggered
- entity: input_boolean.[YourTeslaName]_charge_from_grid
- entity: input_boolean.[YourTeslaName]_stop_charging
- entity: button.wake_up
- entity: button.force_data_update
- entity: device_tracker.location_tracker
- entity: binary_sensor.charger
- entity: binary_sensor.charging
- entity: number.charging_amps
- entity: sensor.range
- entity: sensor.battery
- entity: number.charge_limit
- entity: sensor.time_charge_complete
- entity: lock.charge_port_latch