Fronius

Getting Started

Connect your Fronius inverter system to monitor real-time solar generation, battery state of charge, and grid flows in Joule Genie. Note that the Fronius Solar.web public API does not support timed charge scheduling — this is a monitoring integration.

Step 1: Enable API Access in Solar.web

Log in to your Fronius Solar.web account at solarweb.com. Navigate to Service > REST API (or the equivalent in your portal version). Click Create API Key to generate a new key pair. You will receive an Access Key ID (starting with FKIA) and an Access Key Value (a GUID). Copy both immediately — the Access Key Value is shown once and cannot be retrieved later.

Step 2: Add the Integration in Joule Genie

In Joule Genie, go to Settings > Integrations > Add Integration and select Fronius from the Inverter category. Enter your Access Key ID and Access Key Value.

Step 3: Select Your PV System

Click Find my systems. Joule Genie will connect to Solar.web and list all PV systems registered to your account. Select the site you want to monitor. The peak power (kWp) is shown to help identify the correct site.

Step 4: Verify Connection

Within a few minutes, the dashboard will show real-time solar generation, battery state of charge, and grid flows. Data is sourced from the Solar.web flowdata endpoint and updates on the same 5-minute cycle as Solar.web itself.

API Access Notes

• The Fronius Solar.web API is a pay-per-use service billed by data points. Joule Genie uses the flowdata endpoint which counts as a single data point per poll. At the default polling interval this is well within the free tier allowance.
• If your system uses a Fronius Datamanager or Fronius Smart Meter, ensure the device is online and reporting to Solar.web before connecting.

Troubleshooting

• "Unauthorized"? Regenerate the API key in Solar.web — keys cannot be retrieved after initial creation. Note the new Access Key Value immediately.
• No systems listed? Ensure at least one system is visible and actively logging data in your Solar.web account.
• Readings showing zero? The system may be offline or the Solar.web flowdata endpoint may return null when the inverter is in night mode. This is normal.