SL Energy + SG Ready

What Zerofy can do with SL Energy 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 SL Energy home system (3–12 kW) can cover on sunny days.
• Zerofy gets new SL Energy data every 5 minutes. Heat pumps shouldn’t switch often, so set a minimum runtime in Autopilot.
• Zerofy also shows your SL Energy 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 SL Energy and SG Ready offer on their own

SL Energy: SL Energy sells its own heat pumps (SL-HP9KL and SL-HP12/18KR, 12.6 to 23.8 kW, R32) in the iShare-Home package, and its SmartBox gathers data from inverter, meter, wallbox and heat pump. Whether the heat pump runs on solar surplus isn’t documented publicly.

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.

Zerofy connects the two: it reads SL Energy production and controls your SG Ready heat pump to match, together with your other devices in one app, with dynamic tariffs and forecast-based Smart mode.

Setting up SL Energy and SG Ready in Zerofy

1. Connect SL Energy

Zerofy connects to the SL Energy cloud: you log in with your SL Energy monitoring account (the one you use in the Smart M app).

1. Make sure your inverter is online and registered on the SL Energy monitoring platform.
2. In Zerofy, choose SL Energy and log in with your SL Energy account to grant access.

Good to know: For the battery, Zerofy supports forced charging but not switching the battery mode.

Step-by-step guide for SL Energy

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 SL Energy solar production.

Learn more about Smart Mode

About SL Energy and SG Ready

SL Energy – SL Energy (Slenergy Technology (Anhui) Co., Ltd., China) makes hybrid inverters such as the single-phase SL3.6-6KLV-W and SL3-10KLH-W and the three-phase SL5-12KRH-W, plus SL-BH high-voltage batteries. It also sells complete home packages (iShare-Home) with its own heat pumps and wallbox. Monitoring app: Smart M.

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 SL Energy