Sungrow + SG Ready

What Zerofy can do with Sungrow and SG Ready

In practice

• When there’s enough surplus, Zerofy switches the relay and the heat pump receives the SG Ready signal. How it reacts – for example by heating the hot-water tank to a higher temperature – is set in the heat pump’s own controller.
• A heat pump draws roughly 1–3 kW while running, which a typical Sungrow home system (3–10 kW) can cover on sunny days.
• Zerofy gets new Sungrow data every 5 minutes. Heat pumps shouldn’t switch often, so set a minimum runtime in Autopilot.
• Zerofy also shows your Sungrow battery, so you can see whether surplus goes into the battery or into the heat pump.
• Set in the heat pump controller how many degrees the hot-water and heating setpoints rise in the boost state (“recommended operation”); the default differs by manufacturer. Fronius and Enphase only switch between normal and recommended operation, so the heat pump keeps its own minimum run times.

What Sungrow and SG Ready offer on their own

Sungrow: SH-RT inverters have a DO relay that the iSolarCloud app can switch on export (Intelligent Mode: on once export reaches a set power, for at least 20 minutes), for example for an SG Ready heat pump via a contactor. The iHomeManager also has a DO port for heat pump control.

SG Ready: Several inverter energy managers drive SG Ready directly: Fronius (GEN24 or Datamanager 2.0 with Smart Meter and a 12 V relay), SMA Sunny Home Manager 2.0 (relay or I/O module), Huawei EMMA, SolarEdge Home Load Controller or Smart Energy Relay, Sungrow SH-RT hybrids (built-in DO relay) and the Enphase IQ Energy Router+. Most of them switch on a fixed surplus threshold.

Directly, without Zerofy: The inverter’s DO relay (or the iHomeManager’s DO port) can drive an SG Ready heat pump input, switched by iSolarCloud on surplus export.

Zerofy is the alternative if you want Sungrow, SG Ready and your other devices in one app, with dynamic tariffs and forecast-based Smart mode.

Setting up Sungrow and SG Ready in Zerofy

1. Connect Sungrow

Zerofy connects to your Sungrow system through the iSolarCloud cloud, using your iSolarCloud login.

1. Make sure your Sungrow inverter is online and registered in iSolarCloud.
2. Add Sungrow in Zerofy and log in with your iSolarCloud credentials.

Step-by-step guide for Sungrow

2. Connect SG Ready

Zerofy switches the SG Ready inputs through a smart relay such as a Shelly that you connect to Zerofy; Autopilot then sends SG Ready signals based on solar surplus and low electricity prices.

1. Have an electrician wire a smart relay (e.g. Shelly) to the heat pump’s SG Ready inputs.
2. Add the relay to Zerofy.
3. Configure the relay as SG Ready controller in the app and turn on Autopilot.

Good to know: SG Ready gives Zerofy on/off-style states, not temperature readings or setpoints. To use all four states, the relay needs two channels, one per SG Ready input.

Step-by-step guide for SG Ready

3. Turn on Autopilot

In Zerofy, open your SG Ready heat pump, turn on Autopilot and choose Solar – or Smart to also use dynamic tariffs and forecasts. Set the priority, activation threshold and minimum runtime.

Dynamic tariffs

Zerofy can also run your SG Ready heat pump on dynamic electricity prices (EPEX Spot or Nord Pool, e.g. Tibber or aWATTar) or on a fixed time-of-use tariff. Smart mode combines those prices with forecasts of your household consumption and your Sungrow solar production.

Learn more about Smart Mode

About Sungrow and SG Ready

Sungrow – Chinese inverter and storage maker based in Hefei. Homes typically have an SH-RS single-phase hybrid inverter (3–6 kW) or an SH-RT three-phase hybrid inverter (5–10 kW) with the SBR battery (6.4–25.6 kWh, 3.2 kWh modules), connected to the cloud through a WiNet-S/S2 dongle. Monitoring app: Sungrow iSolarCloud.

SG Ready – SG Ready (Smart Grid Ready) is a label introduced in 2012 by the German Heat Pump Association (BWP) for heat pumps that an external controller can switch between four operating states via two contacts. It is a signalling convention, not a data protocol: the heat pump’s own controller decides how far to raise temperatures in the boost state. Products: Heat pumps with the SG Ready label (two potential-free control inputs), from many manufacturers.

Manufacturer information last checked: October 2026.

All devices that work with Sungrow