Using Powston in Home Assistant

Ian Connor
Jul 15, 2024By Ian Connor

When you signup to Powston, we provide you with an MQTT username and password. This will allow your inverter to read important metrics, including today's forecasts and price thresholds for devices. These thresholds help you determine the optimal price point for running a device for 1 to 5 hours a day. To set up Powston, we have made the MQTT topics discoverable.

Install MQTT in Home Assistant:

* Open Home Assistant

* Go to Configuration > Integrations > Add Integration.

* Search for MQTT and install it.

* Enter your issued username and password.

MacBook Pro near white open book

Configure Discovery Topic:

* Your username is also the prefix for the discovery topic.

* Replace "ian" with your username in the Home Assistant topic.

* Enable discovery to allow Home Assistant to find your devices automatically.

person catching light bulb


Receive Price Updates:

* Prices are pushed every five minutes.

* After a few minutes, you should start to see entities you can use.

* For example, search for "4_hour" to find the price for approximately 4 hours of runtime.
 
As an example, today's price for a 4-hour runtime might be about 2c/kWh. Set your automation rule to turn on when the price is below this threshold and off when it is above it.

orange megaphone on orange wall

The prices are always changing, so for devices that need to run a certain number of hours per day, such as a pool pump, it's best to choose the cheapest price rather than a fixed amount.

PS:  If you ask LocalVolts to add you to Powston, we will push their API's expected costs through for the most accurate price possible. This can help automate processes with prices that factor in certificates, market fees, and other variable costs. Additionally, it accounts for elements of fixed costs and semi-variable fees such as demand charges and maximum levels, which are crucial for optimization and specific to you.