If you own a heat pump, you should operate it using as much self-generated PV power as possible. This helps your investment pay off much faster.
However, options for running the heat pump only when sufficient solar power is available are often limited. In the worst-case scenario, your heat pump starts up at night and relies on grid import to increase your storage tank temperature. This happens because there is no communication between your PV system and the heat pump.
Our app provides a solution for this.
Add heat pump directly
We already support adding various heat pumps directly in our app.
To do this, go to:
-> Devices
-> Add device
-> Heat pump
Control via SG-Ready or PV-Ready
Most modern heat pumps feature an SG-Ready (Smart Grid Ready) or PV-Ready (Photovoltaic Ready) input. Via this input, your heat pump receives a signal that sufficient solar power is available and starts producing hot water by increasing the target temperature of the storage tank. In effect, you are storing electricity in the form of thermal energy. In most cases, this increase in storage tank temperature ensures that the heat pump requires almost no electricity at night.β
Activating the input, configuring the temperature increase, and setting the minimum runtime must be done directly on the heat pump controller. You can find detailed information in your heat pump's user manual.
SG-Ready Operating States
SG-Ready defines a total of 4 operating states, 2 of which are typically used. When PV surplus is available, operating state 3 is switched. This acts as an "ON recommendation," allowing the heat pump to decide independently. βOnce PV surplus is no longer available, the heat pump switches back to operating state 2 (normal operation).
- - More information about operating states on the website of the German Heat Pump Association (BWP)
- - Database of SG-Ready compatible heat pumps
Circuit Setup
We recommend operating the Shelly 1 with 12/24 V DC. Electrical work on 230 V must only be carried out by a qualified electrician. Materials required: Shelly 1, 12 V DC power supply, cables/connectors.
Connect the output of the Shelly 1 to the SG/PV-Ready interface on your heat pump.
The heat pump interface usually operates at a voltage of 3.6β5 V DC. Do not apply external voltage to the switching input of the heat pump.

Setting up the heat pump
During setup, make sure to enter the correct power rating. The power rating corresponds to the power consumption of your heat pump in PV mode and serves as the switch-on threshold for activating the switch so your heat pump can begin converting excess solar power into heat energy. Please note that if grid import occurs, the heat pump will return to its normal operating mode.
In the settings section of our app, you can use the feed-in buffer to define the minimum power reserved as a buffer for the building or the maximum allowed grid import before a switch turns off.βFor example, if your feed-in buffer is set to 200 W, at least 200 W will always be exported to the public grid. If grid feed-in drops below 200 W, the switch turns off. If the feed-in buffer is set to -500 W, grid import is permitted. The switch will only turn off if grid import exceeds 500 W. This allows you to customize control based on your individual requirements and system size.