Fronius + OCPP chargers

What Zerofy can do with Fronius and OCPP chargers

In practice

• Zerofy adjusts the charging current of your OCPP charger but doesn’t switch phases. On a three-phase connection, solar charging needs at least about 4.1 kW of surplus (6 A × 3 × 230 V); on a single-phase connection about 1.4 kW.
• A typical Fronius home system (3–10 kW) needs a sunny midday to reach the 4.1 kW three-phase minimum. Wired single-phase, the charger starts from about 1.4 kW but charges at no more than about 3.7 kW.
• 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.
• Many chargers switch off their own app or solar mode while an external OCPP backend is active (for example enercab, Growatt THOR, SolaX in its OCPP scene), so Zerofy takes over. Zerofy sets the power over OCPP but not the phases, so a three-phase charger needs about 4.1 kW of surplus (3×6 A) unless it switches phases by itself.

What Fronius and OCPP chargers 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.

OCPP chargers: OCPP itself has no solar mode: since 1.6 it carries smart-charging profiles, so the backend sets the current limit and decides when to charge. Solar behaviour therefore comes from whichever system is the backend, or from the charger’s own meter-based mode.

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

Setting up Fronius and OCPP chargers 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 OCPP chargers

You enter Zerofy’s OCPP URL in your charger’s OCPP settings; Zerofy then acts as the backend and can start, stop and set the charging power.

1. Check that your charger supports OCPP 1.6 and lets you change the backend address.
2. In Zerofy, add an OCPP charger and copy the OCPP URL.
3. Paste it into the OCPP settings of your charger’s app or web page and wait for it to connect.

Good to know: Not every OCPP charger lets the owner choose the backend: some need the installer’s service tool (Alfen, ABB), some pick from a preset list (Peblar) or whitelist the address first (Smappee), and some offer no owner OCPP at all (Tesla Wall Connector, Ohme).

Step-by-step guide for OCPP chargers

3. Turn on Autopilot

In Zerofy, open your OCPP 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 OCPP 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 OCPP chargers

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.

OCPP chargers – OCPP (Open Charge Point Protocol) is the open standard from the Open Charge Alliance for communication between a charger and a management system; version 1.6 from 2015 is the most widely used, in its JSON variant 1.6J. A charger can only be connected to one OCPP backend at a time. Products: Any charger with OCPP 1.6J and a freely configurable backend, e.g. Alfen Eve, KEBA KeContact P40, Charge Amps Halo, Autel MaxiCharger, enercab smart.

Manufacturer information last checked: October 2026.

All devices that work with Fronius