Fronius + Zaptec

What Zerofy can do with Fronius and Zaptec

In practice

• Zerofy can switch your Zaptec charger between one and three phases. Solar charging can therefore start at about 1.4 kW of surplus (6 A on one phase) and move to three phases once the surplus passes about 4.1 kW.
• A typical Fronius home system (3–10 kW) reaches the 1.4 kW single-phase minimum on most bright days; three-phase charging from about 4.1 kW needs a sunny midday or a larger system.
• Zerofy gets new Fronius data every 5 minutes and adjusts accordingly. A minimum runtime and an activation threshold in Autopilot keep passing clouds from interrupting charging.
• Zerofy also shows your Fronius battery, so you can see whether surplus goes into the battery or into the car.
• If your car is connected to Zerofy too, turn on Autopilot for either the car or the charger, not both.
• Ask whoever set up the charger to make you site owner in the Zaptec portal or to grant the permissions; otherwise Zerofy can only switch charging on and off instead of following the surplus. With phase switching the Go 2 starts at about 1.4 kW on one phase; on three phases it needs about 4.1 kW.

What Fronius and Zaptec offer on their own

Fronius: Fronius sells its own Wattpilot wallboxes, manufactured by go-e in Austria, a company Fronius holds a stake in. Wattpilot charges on solar surplus from 1.38 kW with automatic 1/3-phase switching, but only with a compatible Fronius inverter (GEN24, Verto, SnapINverter with Datamanager 2.0) and a Fronius Smart Meter at the grid connection point.

Zaptec: Since June 2026 Zaptec offers its own solar charging in the Netherlands, Belgium, Germany, Switzerland and Luxembourg for Go, Go 2 and Pro. It needs a Zaptec Sense (Generic or P1) that detects local production, a Home installation with up to three chargers and a TN grid; the app then offers “Surplus + grid” and “Surplus only”.

Zerofy connects the two: it reads Fronius production and controls your Zaptec charger to match, together with your other devices in one app, with dynamic tariffs and forecast-based Smart mode.

Setting up Fronius and Zaptec in Zerofy

1. Connect Fronius

Zerofy reads your system from Fronius Solar.web through a guest account that you create for Zerofy.

1. Make sure your Fronius inverter is online and shows up in Solar.web.
2. In Solar.web, go to Settings → Permissions and create a new guest account.
3. Add Fronius in Zerofy and log in with the guest account credentials.

Step-by-step guide for Fronius

2. Connect Zaptec

Zerofy connects with your Zaptec portal login and controls charging, current and phases through the Zaptec cloud.

1. Make sure your Zaptec charger is online and registered in the Zaptec portal.
2. In Zerofy, add a Zaptec charger and enter your Zaptec portal credentials.

Good to know: Only the site owner in the Zaptec portal may change current and phases. Without that permission Zerofy can only start and stop charging, and the app tells you so. Charging sessions only appear in the history after the car has been unplugged.

Step-by-step guide for Zaptec

3. Turn on Autopilot

In Zerofy, open your Zaptec charger, 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 Zaptec charger 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 Fronius solar production.

Learn more about Smart Mode

About Fronius and Zaptec

Fronius – Austrian manufacturer of inverters, welding and battery-charging technology. Homeowners typically have a Primo GEN24 (single-phase, 3–6 kW) or Symo GEN24 (three-phase, 3–10 kW) hybrid inverter, older Primo/Symo SnapINverters, and the Fronius Reserva battery (6.3–15.8 kWh). Monitoring app: Fronius Solar.web.

Zaptec – Zaptec is a Norwegian charger maker. The Zaptec Go 2 is a very compact 22 kW charger with a MID meter, free built-in 4G and automatic switching between one and three phases, and like Easee it also runs on 3×230 V IT grids. Products: Zaptec Go 2, Zaptec Go, Zaptec Pro.

Manufacturer information last checked: October 2026.

All devices that work with Fronius