If you have a heat pump, you should operate it with self-generated PV electricity wherever possible. This will make your investment pay for itself all the quicker.
However, there are often insufficient options for running the heat pump when there is sufficient solar power available. In the worst case scenario, your heat pump will start at night and draw power from the grid to increase your storage temperature. This is because there is no communication between your solar system and the heat pump.
Our app has a solution for this.
Control via SG-Ready or PV-Ready
Most modern heat pumps have an SG-Ready (Smart Grid Ready) or PV-Ready (Photovoltaic Ready) input. Via this input, your heat pump receives the signal that sufficient solar power is available and it starts producing hot water by increasing the set temperature of the storage tank. You are therefore storing electricity in the form of thermal energy. In most cases, this increase in the cylinder temperature is sufficient for the heat pump to hardly need any electricity at night.
The activation of the input, the temperature increase and the minimum running time must be set via the control unit on the heat pump. Information on this can be found in the operating instructions for your heat pump.
SG-Ready operating states
SG-Ready provides for a total of 4 operating states, 2 of which are used. If there is a PV surplus, operating state 3 is used, which is a “switch-on recommendation”. The heat pump therefore decides independently whether to switch back to operating state 2 (normal operation) if there is no longer a PV surplus.
- More information on the operating states on the website of the German Heat Pump Association
- e.V.Database on SG-Ready capable heat pumps
Structure of the circuit
We recommend operating the Shelly Plus 1 with 12/24 V DC. Electrical work on 230V may only be carried out by a qualified electricianMaterial:Shelly Plus 1Power supply 12V DCCable/plug
Connect the output of the Shelly Plus 1 to the SG/PV-Ready interface of your heat pump.
A voltage of 3.6-5V DC is usually applied to the heat pump interface. No external voltage may be applied to the switching input of the heat pump.
Setting up the heat pump
First you need to set up the Shelly Plus 1 and connect it to the internet and the Shelly Cloud.
Then you can connect the Shelly Plus 1 to our app.
When setting up, you must ensure that you enter the correct rated output. The rated output corresponds to the power requirement of your heat pump in PV mode and is the switch-on point at which the switch is activated so that your heat pump starts to convert excess solar power into heat energy. Please note that the heat pump returns to its normal operating mode when the grid is drawn.
In the settings area of our app, you can use the ECO offset to define the minimum power to be kept as a buffer for the building or the minimum grid draw permitted before a switch switches off. 200W, for example, means that at least 200W will always be fed into the public grid. If the feed-in is less than 200 W, the switch is switched off. If the ECO offset is -500 W, for example, grid supply is permitted. The switch is only switched off if more than 500 W is drawn from the grid. This allows you to adapt the control system to your individual needs and system dimensions.